Tadalafil (Cialis) Interactions You Should Know About

For some, tadalafil (Cialis) may be a preferred medication to get or maintain an erection.

Why? Because tadalafil lasts longer than other similar medications.

However, high blood pressure and heart disease are also more common as men get older. And medications used to treat them can interact with tadalafil. Some interactions can have dangerous effects and should be avoided altogether. Others just require monitoring.

Your regular provider, or a telehealth service like GoodRx Care, may have prescribed tadalafil for your ED. In any case, it’s important to know about tadalafil interactions and how to manage them.

Common tadalafil interactions you should be aware of

Tadalafil is a phosphodiesterase-5 (PDE-5) inhibitor commonly used to treat ED. But it can be used to treat other medical conditions, too. This includes symptoms of benign prostatic hyperplasia (BPH) with or without ED. It’s also available as Adcirca and Alyq for treating pulmonary hypertension.

No matter why you’re taking tadalafil, these interactions still apply. Some people take tadalafil daily, while others only take it as needed. And one dose can stick around in your body for several days. This can result in interactions — even if you didn’t take tadalafil and another medication on the same day. So, it’s best to check with your healthcare provider first before starting a new medication.

Below, we’ll detail nine of the most common tadalafil interactions to keep in mind.

1. Nitrates

Nitrates are used to treat and prevent angina (chest pain) caused by heart disease. Examples include nitroglycerin (Nitrostat), isosorbide mononitrate (Monoket), and isosorbide dinitrate (Isordil).

PDE-5 inhibitors, like tadalafil, are contraindicated with nitrates. This means the combination should be avoided since it can cause harm. Taking these medications together can result in a severe drop in blood pressure (called hypotension). This can make you feel dizzy and possibly cause you to faint or pass out.

2. Alpha blockers

Alpha blockers are a medication class used to treat high blood pressure. Some are also used to help with urinary symptoms from BPH. Examples include terazosin (Hytrin), tamsulosin, (Flomax), and doxazosin (Cardura). Alpha blockers can cause your blood vessels to widen. This can result in a decrease in your blood pressure.

Tadalafil also causes your blood vessels to widen. So taking an alpha blocker with tadalafil can significantly reduce your blood pressure. This can cause dizziness and fainting in some people. If you’re taking tadalafil for ED, use caution when taking these medications together. However, it’s not recommended to take them together at all for BPH.

Let your healthcare provider know if you experience dizziness or fainting with this combination.

3. Blood pressure medications

It’s not uncommon to take a blood pressure medication with tadalafil. That’s because having high blood pressure can be a contributing factor for ED. What’s more, some blood pressure medications can also cause ED.

There are several types of medications available to lower your blood pressure if it’s too high. And they all work differently to achieve this effect. Examples include diuretics (water pills), angiotensin-converting enzyme (ACE) inhibitors, and calcium channel blockers. When they’re taken with tadalafil, some people experience a small drop in blood pressure.

This interaction may not cause meaningful blood pressure changes for everyone. But it’s still important to use caution with this combination.

4. sGC stimulators

Riociguat (Adempas) is used to control pulmonary hypertension. And vericiguat (Veroquvo) is used in certain types of heart failure. Both medications are soluble guanylate cyclase (sGC) stimulators. They work by relaxing blood vessels to improve blood flow.

Like nitrates, these medications should not be taken with tadalafil. That’s because your blood pressure could drop dangerously low with this combination.

5. PDE-5 inhibitors

As discussed earlier, tadalafil is a PDE-5 inhibitor. Other common examples of this class include sildenafil (Viagra, Revatio) and vardenafil (Levitra).

For most people, taking more than one PDE-5 inhibitor may not provide an added benefit. Instead, you may be more likely to experience side effects, like dizziness, headache, and flushing.

Your healthcare provider may recommend taking two PDE-5 inhibitors in certain situations. But you should always check with them before taking more than one of these medications at the same time.

6. Protease inhibitors

Protease inhibitors are medications used to treat viral infections like hepatitis C and HIV. Examples include ritonavir (Norvir), darunavir (Prezista), and atazanavir (Reyataz). Sometimes they’re combined with medications to help them work better. One example of this is Paxlovid (nirmatrelvir/ritonavir) for COVID-19.

Ritonavir has been shown to raise the blood levels of tadalafil when taken together. Other protease inhibitors may have a similar interaction. This can increase the risk of side effects like vision changes, low blood pressure, and prolonged erections.

Your healthcare provider may limit your tadalafil dosage with this combination. This may depend on how often you’re taking it.

7. Anti-infective medications

Certain anti-infective medications, including antibiotics and antifungals, interact with many medications. Examples of these include erythromycin (Ery-Tab), ketoconazole, and itraconazole (Sporonax).

Similar to protease inhibitors, these medications may increase tadalafil levels in the blood. This may result in dizziness and fainting. Your tadalafil dosage may need to be adjusted if you’re also taking one of these medications.

8. Grapefruit

You’ve probably heard that grapefruit can interact with medications. And tadalafil — as well as other PDE-5 inhibitors — is no exception. For some people, this combination may cause a drop in blood pressure. But this can vary by person.

Is consuming grapefruit or grapefruit juice part of your regular routine? If so, ask your healthcare provider about how much is safe with your medications.

9. Alcohol

Both tadalafil and alcohol can cause your blood vessels to relax. When you combine the two, this effect can cause your blood pressure to drop. This may be more apparent when changing positions (like from sitting to standing). You may feel dizzy and be more likely to fall.

Because of this, it’s best to minimize or avoid alcohol while taking tadalafil. And if you’re taking tadalafil for ED, alcohol isn’t going to do you any favors. Talk to your healthcare provider about how much alcohol is safe for you to drink.

Tadalafil Warnings

This drug comes with several warnings.

Allergy warning

Tadalafil can cause a severe allergic reaction. Symptoms can include:

      • rash
      • hives
      • trouble breathing or swallowing
      • swelling of your lips, throat, or tongue

If you develop these symptoms, call 911 or go to the nearest emergency room.

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

Grapefruit interaction warning

Eating grapefruit or drinking grapefruit juice may increase the levels of tadalafil in your blood. This raises your risk for side effects.

Alcohol interaction warning

Don’t drink large amounts of alcohol when taking tadalafil. Both alcohol and tadalafil can dilate (widen) your blood vessels. When used together, they can cause your blood pressure to drop.

Warnings for people with certain health conditions

For people with heart disease: Sexual activity creates a risk for your heart. Using tadalafil may increase that risk. Don’t use tadalafil if you have a heart condition and your doctor has advised against sexual activity.

For people at risk for prolonged erections: Tadalafil may cause priapism. This condition causes a painful, long-lasting erection. It is a medical emergency. Talk with your doctor before using tadalafil if you have a condition that puts you at higher risk for priapism. These conditions include blood cell conditions such as sickle cell anemia, multiple myeloma, or leukemia Peyronie’s disease (a curved or deformed penis).

For people with vision problems: Retinitis pigmentosa is a rare genetic eye disease. Tadalafil hasn’t been studied in people with this condition, and its use isn’t recommended. Tell your doctor if you’ve ever had severe vision loss, including a condition called NAION (non-arteritic anterior ischemic optic neuropathy). If you’ve had NAION and take tadalafil, you may be at increased risk for having NAION again.

For people with kidney disease or on dialysis: Your body may not be able to get rid of tadalafil correctly. This means the drug would stay in your body longer and raise your risk for side effects. Your doctor may start you on a lower dosage, have you take it less often, or not prescribe it at all.

For people with liver problems: Your body may not process tadalafil correctly. This means the drug would stay in your body longer and raise your risk for side effects. Your doctor may start you on a lower dosage, have you take it less often, or not prescribe it at all.

For people with bleeding disorders or peptic ulcers: Tadalafil hasn’t been studied in people with these conditions. Using tadalafil may cause or worsen bleeding or ulcers. If you take tadalafil, your doctor may monitor you more closely.

Warnings for other groups

For pregnant women: Studies of this drug in pregnant animals haven’t shown risk to the fetus. However, there aren’t enough studies done in pregnant women using the drug for PAH to show whether the drug poses a risk to a human fetus.

Talk with your doctor if you’re pregnant or planning to become pregnant. Animal studies don’t always predict the way humans would respond. Therefore, this drug should only be used in pregnancy if clearly needed.

For women who are breastfeeding: It isn’t known if tadalafil passes into breast milk. If it does, it may cause serious effects in a child who is breastfed. Talk with your doctor if you’re taking tadalafil and you want to breastfeed.

For seniors: If you are age 65 years or older, your body may process this drug more slowly. Your doctor may start you on a lower dosage so that tadalafil doesn’t build up too much in your body. High levels of the drug in your body can be dangerous.

For children: Children younger than 18 years old shouldn’t use tadalafil. It’s not known if tadalafil is safe and effective in children.

Serious Side Effects of Taking Cialis

Call your doctor right away if you have serious side effects of Cialis.

Call 911 if your symptoms feel life threatening or if you think you’re having a medical emergency.

Serious side effects and their symptoms can include the following:

  • Priapism (in men). Symptoms can include:
    • a painful erection that won’t go away
  • Vision changes. Symptoms can include:
    • seeing a shade of blue when looking at objects
    • trouble telling the difference between the colors blue and green
    • a sudden decrease or loss of vision in one or both eyes
  • Hearing loss. Symptoms can include:
    • a sudden loss or decrease in hearing
    • ringing in the ears
    • dizziness
  • Low blood pressure. Symptoms can include:
    • feeling lightheaded or dizzy
    • fainting
    • angina (chest pain

Taking Tadalafil With Other Medicines and Herbal Supplements

Taking tadalafil with other medicines and herbal supplements – Brand names: Cialis, Adcirca

Cautions with other medicines

Some medicines do not mix well with tadalafil.

Tell your doctor or pharmacist if you’re taking these medicines before you start tadalafil:

    • nitrates for chest pain, such as glyceryl trinitrate (GTN)
    • riociguat for pulmonary hypertension

Mixing tadalafil with herbal remedies and supplements

There are lots of treatments that claim to be a “herbal Cialis”, but there is no such thing.

A herbal Cialis has never been approved as a treatment for erectile dysfunction. These treatments may also be fake or unsafe.

Some complementary therapies may have ingredients that could affect the way tadalafil works and cause side effects.

There’s not enough information to say whether complementary medicines, herbal remedies and supplements are safe to take with tadalafil. They’re not tested in the same way as pharmacy and prescription medicines. They’re generally not tested for the effect they have on other medicines.

Pregnancy, Breastfeeding and Fertility While Taking Tadalafil

Tadalafil is not often prescribed in pregnancy, but it may be recommended if you have pulmonary hypertension.

Pulmonary hypertension is an extremely serious condition in pregnancy. If you have this condition, it’s important to use reliable contraception (for example a contraceptive implant or a coil) and to talk to your doctor before trying for a baby. You heart condition will need to be assessed so that you can be given information on the risks of pregnancy to your health.

If you become pregnant while taking tadalafil, you will usually be recommended to continue to take it throughout pregnancy. This is because the risks from pulmonary hypertension are potentially life-threatening without treatment.

It’s important to let your doctors know that you are pregnant as early as possible. This is because you will need to be reviewed in a specialist pregnancy and heart clinic throughout your pregnancy. You will be considered a high-risk pregnancy and will have a lot of additional care.

Tadalafil and breastfeeding

If you are breastfeeding and have pulmonary hypertension, tadalafil is not usually prescribed, unless a specialist recommends it.

Tadalafil and fertility

There’s no evidence to suggest that taking tadalafil will reduce fertility in either women or men.

However, speak to a pharmacist or doctor before taking it if you’re trying to get pregnant.

Who Can Not Take Cialis ?

Tadalafil is not suitable for some people.

To make sure it’s safe for you, tell your doctor if you:

    • have ever had an allergic reaction to tadalafil or any other medicine
    • are taking medicines called nitrates for chest pain (angina)
    • have a serious heart and liver problem
    • have recently had a stroke or a heart attack
    • have low blood pressure (hypotension) or uncontrolled high blood pressure (hypertension)
    • have ever lost your vision due to reduced blood flow to the eye
    • have sickle cell anaemia (an abnormality of red blood cells)
    • have leukaemia (cancer of blood cells)
    • have multiple myeloma (cancer of bone marrow)
    • have Peyronie’s disease (curved penis) or a similar problem with your penis
    • have a liver or kidney condition
    • have a heart condition – your doctor will advise you whether your heart can take the additional strain of having sex

Why am I using CIALIS?

Why am I using CIALIS?

CIALIS contains the active ingredient tadalafil. CIALIS belongs to a group of medicines called phosphodiesterase type 5 inhibitors.
CIALIS is used to treat:
  • erectile dysfunction, also known as impotence, in men. This is when a man cannot get, or maintain, a hard erect penis suitable for sexual activity. Following sexual stimulation, CIALIS works by helping the blood vessels in your penis to relax, allowing the flow of blood into your penis. The result of this is improved erectile function. CIALIS will only treat erectile dysfunction if you are sexually aroused. You and your partner will need to engage in foreplay, just as you would if you were not taking a medicine for erectile dysfunction.
  • urinary symptoms associated with a common condition called benign prostatic hyperplasia. This is when the prostate gland gets bigger with age. Symptoms include difficulty in starting to pass urine, a feeling of not completely emptying the bladder and a more frequent need to pass urine even at night. CIALIS improves blood flow to, and relaxes the muscles of, the prostate and bladder which may reduce symptoms of benign prostatic hyperplasia.
Your doctor may have prescribed you CIALIS to treat either, or both of these conditions.
CIALIS contains the active ingredient tadalafil. CIALIS is used to treat erectile dysfunction and urinary symptoms associated with benign prostatic hyperplasia in adult men.

What should I know before I use CIALIS?

Do not use if you have ever had an allergic reaction to CIALIS or any of the ingredients listed at the end of the CMI.
Do not take CIALIS if you are currently taking any nitrates or amyl nitrite.
Talk to your doctor if you have any other medical conditions such as heart problems or take any other medicines.

What if I am taking other medicines?

Some medicines may interfere with CIALIS and affect how it works.
A list of these medicines is in Section

How do I use CIALIS?

Always take CIALIS exactly as your doctor has told you.
Follow all directions given to you by your doctor or pharmacist.
More instructions can be found in Section in the full CMI.

What should I know while using CIALIS?

Things you should do
Remind any doctor, dentist or pharmacist you visit that you are using CIALIS.
If you have emergency treatment for any suspected heart condition tell the emergency medical or ambulance staff that you are taking CIALIS.
Things you should not do
Do not take CIALIS to treat any other complaints.
Do not give your medicine to anyone else, even if they have the same condition as you.
Driving or using machines
Be careful driving or operating machinery until you know how CIALIS affects you.
Drinking alcohol
CIALIS can be taken with or without food or alcohol. However, drinking alcohol may affect your ability to get an erection, so avoid excessive alcohol.
Looking after your medicine
Store below 25°C.
Keep it where young children cannot reach it.

Are there any side effects?

CIALIS may cause chest pain, headache or migraine, flushing, sweating, nausea or vomiting, fatigue, back pain, muscle pain.
Active ingredient: tadalafil
Consumer Medicine Information (CMI)
This leaflet provides important information about using CIALIS. You should also speak to your doctor or pharmacist if you would like further information or if you have any concerns or questions about using CIALIS.

Side Effects of Cialis

Tadalafil is used to treat men who have erectile dysfunction (also called sexual impotence). Tadalafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where this enzyme works.

Erectile dysfunction is a condition where the penis does not harden and expand when a man is sexually excited, or when he cannot keep an erection. When a man is sexually stimulated, his body’s normal response is to increase blood flow to his penis to produce an erection. By controlling the enzyme, tadalafil helps to maintain an erection after the penis is stroked by increasing blood flow to the penis. Without physical action to the penis, such as that occurring during sexual intercourse, tadalafil will not work to cause an erection.

Tadalafil is also used to treat men who have signs and symptoms of benign prostatic hyperplasia (BPH). BPH is caused by an enlarged prostate. Men with BPH usually have difficulty urinating, a decreased flow of urination, hesitation at the beginning of urination, and a need to get up at night to urinate. Tadalafil will make these symptoms less severe and reduce the chance that prostate surgery will be needed. This medicine is also used to treat erectile dysfunction and signs and symptoms of BPH.

Tadalafil is also used in both men and women to treat the symptoms of pulmonary arterial hypertension to improve your ability to exercise. This is high blood pressure that occurs in the main artery that carries blood from the right side of the heart (the ventricle) to the lungs. When the smaller blood vessels in the lungs become more resistant to blood flow, the right ventricle must work harder to pump enough blood through the lungs. Tadalafil works on the PDE5 enzyme in the lungs to relax the blood vessels. This will increase the supply of blood to the lungs and reduce the workload of the heart.

This medicine is available only with your doctor’s prescription. .

This product is available in the following dosage forms:

  • Suspension
  • Tablet

Before Using

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Use of Cialis® tablet is not indicated for use in the pediatric population. Safety and efficacy have not been established.

Appropriate studies have not been performed on the relationship of age to the effects of Adcirca® and Alyq™ tablet in the pediatric population. Safety and efficacy have not been established.


Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of tadalafil in the elderly. However, elderly patients are more sensitive to the effects of this medicine than younger adults.


There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Amyl Nitrite
  • Boceprevir
  • Erythrityl Tetranitrate
  • Isosorbide Dinitrate
  • Isosorbide Mononitrate
  • Nitroglycerin
  • Pentaerythritol Tetranitrate
  • Propatyl Nitrate
  • Riociguat
  • Telaprevir
  • Vericiguat

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Alfuzosin
  • Atazanavir
  • Bunazosin
  • Clarithromycin
  • Cobicistat
  • Conivaptan
  • Darunavir
  • Erythromycin
  • Fosamprenavir
  • Idelalisib
  • Indinavir
  • Itraconazole
  • Ketoconazole
  • Lenacapavir
  • Lopinavir
  • Moxisylyte
  • Nefazodone
  • Nelfinavir
  • Phenoxybenzamine
  • Phentolamine
  • Posaconazole
  • Prazosin
  • Ritonavir
  • Saquinavir
  • Simeprevir
  • Simvastatin
  • Tamsulosin
  • Telithromycin
  • Terazosin
  • Tipranavir
  • Trimazosin
  • Urapidil
  • Voriconazole

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Doxazosin
  • Rifampin
  • Silodosin

Other Interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

  • Grapefruit Juice

Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.

  • Ethanol

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Abnormal penis, including curved penis and birth defects of the penis (eg, angulation, cavernosal fibrosis, or Peyronie’s disease) or
  • Leukemia (blood related cancer) or
  • Multiple myeloma (blood related cancer) or
  • Sickle-cell anemia (blood disorder)—Use with caution. May increase risk of unwanted side effects (eg, prolonged erection of the penis).
  • Age greater than 50 years or
  • Coronary artery disease or
  • Diabetes or
  • Hyperlipidemia (high lipids or fats in the blood) or
  • Hypertension (high blood pressure) or
  • Low cup to disc ratio (eye condition also called “crowded disc”) or
  • Smoking—Use with caution. May increase risk for non–arteritic anterior ischemic optic neuropathy (NAION).
  • Angina (severe chest pain) or
  • Arrhythmia (irregular heartbeat), uncontrolled or
  • Heart attack (within the last 3 months) or
  • Heart failure (within the last 6 months) or
  • Hypertension (high blood pressure), uncontrolled or
  • Hypotension (low blood pressure) or
  • Retinal disorders (eye problem) or
  • Retinitis pigmentosa (an inherited eye disorder) or
  • Stroke, recent history of—Should not be used in patients with these conditions.
  • Bleeding disorders or
  • Stomach ulcers—Use must be determined by your doctor. May increase your risk of bleeding.
  • Heart or blood vessel disease or
  • Pulmonary veno-occlusive disease or PVOD (a type of lung disease)—Use with caution. May make this condition worse.
  • Kidney disease, mild or moderate or
  • Liver disease, mild or moderate—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
  • Non–arteritic anterior ischemic optic neuropathy (NAION, serious eye condition) in one or both eyes, history of—Use with caution. May increase your risk of getting NAION again.

Proper Use

Use tadalafil exactly as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered. Also, do not stop taking this medicine without checking first with your doctor.

This medicine comes with a patient information leaflet. Read and follow these instructions carefully. Read it again each time you refill your prescription in case there is new information. Ask your doctor if you have any questions.

You may take this medicine with or without food.

Swallow the tablet whole. Do not split, break, chew, or crush it.

When using this medicine for erectile dysfunction, the ability to have sexual activity may be improved for up to 36 hours after taking the tablet.

Use only the brand of this medicine that your doctor prescribed. Different brands may not work the same way.


The dose of this medicine will be different for different patients. Follow your doctor’s orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (tablets):
    • For treatment of benign prostatic hyperplasia (daily use):
      • Adults—5 milligrams (mg) as a single dose, no more than once a day, taken at the same time each day.
      • Children—Use is not recommended.
    • For treatment of erectile dysfunction (as needed):
      • Adults—10 milligrams (mg) as a single dose, no more than once a day, taken 30 minutes before you think sexual activity may occur. Your doctor may adjust your dose as needed.
      • Children—Use is not recommended.
    • For treatment of erectile dysfunction (daily use):
      • Adults—2.5 milligrams (mg) once a day, taken at the same time each day, without regard for the timing of sexual activity. Your doctor may adjust your dose as needed.
      • Children—Use is not recommended.
    • For treatment of erectile dysfunction and benign prostatic hyperplasia (daily use):
      • Adults—5 milligrams (mg) once a day, taken at the same time each day, without regard for the timing of sexual activity.
      • Children—Use is not recommended.
    • For treatment of pulmonary arterial hypertension:
      • Adults—40 milligrams (mg) (two 20 mg tablets) taken once a day. Take both tablets at the same time each day. Do not divide the 40 mg dose. Your doctor may adjust your dose as needed.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.


It is important that you tell all of your doctors that you take tadalafil. If you need emergency medical care for a heart problem, it is important that your doctor knows when you last took tadalafil.

If you will be taking this medicine for pulmonary arterial hypertension, it is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. Blood and urine tests may be needed to check for unwanted effects.

If you take tadalafil for pulmonary arterial hypertension, do not take Cialis® or other PDE5 inhibitors, such as sildenafil (Revatio® or Viagra®) or vardenafil (Levitra®). Cialis® also contains tadalafil. If you take too much tadalafil or take it together with these medicines, the chance for side effects will be higher.

If you experience a prolonged erection for more than 4 hours or a painful erection for more than 6 hours, contact your doctor immediately. This condition may require prompt medical treatment to prevent serious and permanent damage to your penis.

This medicine does not protect you against sexually transmitted diseases (including HIV or AIDS). Use protective measures and ask your doctor if you have any questions about this.

It is important to tell your doctor about any heart problems you have now or may have had in the past. This medicine can cause serious side effects in patients with heart problems.

Do not use this medicine if you are also using riociguat or a nitrate medicine, often used to treat angina (chest pain). Nitrate medicines include nitroglycerin, isosorbide, Imdur®, Nitro-Bid®, Nitrostat®, Nitro-Dur®, Transderm Nitro®, Nitrol® Ointment, and Nitrolingual® Spray. Some illegal (“street”) drugs called “poppers” (such as amyl nitrate, butyl nitrate, or nitrite) also contain nitrates. If you need to use a nitrate medicine, take it at least 48 hours after your last dose of tadalafil.

Do not drink excessive amounts of alcohol (eg, 5 or more glasses of wine or 5 or more shots of whiskey) when taking tadalafil. When taken in excess, alcohol can increase your chances of getting a headache or dizziness, increase your heart rate, or lower your blood pressure.

If you experience sudden loss of vision in one or both eyes, contact your doctor immediately.

Check with your doctor right away if you have a sudden decrease in hearing or loss of hearing, which may be accompanied by dizziness and ringing in the ears.

Do not eat grapefruit or drink grapefruit juice while you are using this medicine. Grapefruit and grapefruit juice may change the amount of this medicine that is absorbed in the body.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common

  1. Arm, back, or jaw pain
  2. blurred vision
  3. chest pain, discomfort, tightness, or heaviness
  4. chills
  5. cold sweats
  6. confusion
  7. dizziness
  8. fainting
  9. faintness or lightheadedness when getting up suddenly from a lying or sitting position
  10. fast or irregular heartbeat
  11. headache
  12. hearing loss
  13. increased erection
  14. nausea
  15. nervousness
  16. pain or discomfort in the arms, jaw, back, or neck
  17. pounding in the ears
  18. slow or fast heartbeat
  19. spontaneous penile erection
  20. sweating
  21. unusual tiredness or weakness
  22. vomiting


  1. Painful or prolonged erection of the penis

Incidence not known

  1. Blindness
  2. blistering, peeling, or loosening of the skin
  3. cough
  4. cracks in the skin
  5. decrease or change in vision
  6. diarrhea
  7. difficulty with speaking
  8. double vision
  9. fast, irregular, pounding, or racing heartbeat or pulse
  10. headache, severe and throbbing
  11. hives or welts, itching, skin rash
  12. inability to move the arms, legs, or facial muscles
  13. inability to speak
  14. joint or muscle pain
  15. loss of heat from the body
  16. numbness or tingling of the face, hands, or feet
  17. red skin lesions, often with a purple center
  18. red, irritated eyes
  19. red, swollen skin
  20. redness of the skin
  21. redness or soreness of the eyes
  22. scaly skin
  23. slow speech
  24. sores, ulcers, or white spots in the mouth or on the lips
  25. stomach pain
  26. sudden cardiac death
  27. swelling of the feet or lower legs

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  1. Belching
  2. heartburn
  3. indigestion
  4. stomach discomfort, upset, or pain

Less common

  1. Bloody nose
  2. body aches or pain
  3. burning, crawling, itching, numbness, prickling, “pins and needles”, or tingling feelings
  4. burning, dry, or itching eyes
  5. burning feeling in the chest or stomach
  6. congestion
  7. difficulty with moving
  8. difficulty with swallowing
  9. dry mouth
  10. dryness or soreness of the throat
  11. excessive eye discharge
  12. eye pain
  13. feeling of constant movement of self or surroundings
  14. feeling of warmth, redness of the face, neck, arms and occasionally, upper chest
  15. fever
  16. hoarseness
  17. lack or loss of strength
  18. loose stools
  19. muscle aching, cramping, or stiffness
  20. neck pain
  21. pain in the arms or legs
  22. pain or burning in the throat
  23. redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
  24. reduced sensitivity to touch
  25. runny or stuffy nose
  26. sensation of spinning
  27. sleepiness or unusual drowsiness
  28. stomach upset
  29. swelling of the eyelids
  30. swelling or puffiness of the eyes or face
  31. swollen joints
  32. tearing
  33. tender, swollen glands in the neck
  34. tenderness in the stomach area
  35. trouble with sleeping
  36. upper stomach pain
  37. voice changes
  38. watering of the eyes


  1. Changes in color vision

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

How to Take Viagra ?

Viagra is an oral medication that comes in pill form. In the U.S., it’s prescribed as needed to men with ED.

As-needed Viagra is taken before sex, so you’ll need to do some planning. Be sure to take Viagra one hour (but no more than four hours) before you plan to engage in sexual activity.

Also, you can take it on an empty stomach or with food, though if you’re hitting up a burger joint, know it may take Viagra longer to kick in when taken with fatty foods. For more tips, check out our blog on how to take sildenafil citrate (Viagra).

When you filled your prescription, the pharmacist probably gave you a quick rundown of the basics, which probably included a fair amount of confusing medical jargon. We’re here to break it down for you, so you know exactly how to take sildenafil for erectile dysfunction.

To start, there are typically three dose strengths of sildenafil that healthcare providers will prescribe, based on your needs — 25mg, 50mg and 100mg. For most patients, the recommended dose of sildenafil is 50mg taken as needed, approximately one hour before sexual stimulation. Hims now offers a sildenafil chew at different dosages allowing you to take sildenafil as-needed to suit your sex life.

Based on the effectiveness and ability to tolerate the drug, your healthcare professional may adjust the dosage up to 100mg or down to 25mg.

It is important to note here that the maximum dose per day is 100mg of sildenafil, so don’t take another 100mg if the first isn’t working the way it should.

How to Take Sildenafil With Food

Before popping that little blue pill, there are a few things you should know.

Sildenafil does not protect you from STIs. Therefore, you should always practice safe sex and wear a condom.

You can take sildenafil with food or on an empty stomach. However, avoid high-fat foods, high-fat meal can block the absorption of sildenafil citrate and can make the drug less effective for your erection.

If you do plan to eat a meal before taking sildenafil, make sure to have it as your breakfast or lunch. That way, it gives your body time to digest the food, making it quick and easier for sildenafil to absorb into the bloodstream.

Grapefruit juice may also impede or delay the absorption of sildenafil in the body. Make sure to seek medical advice from a healthcare provider about eating grapefruit and drinking grapefruit juice while taking sildenafil.

How Viagra® Works ?

Millions of men use the brand name medication Viagra® every year, making it the single-most popular medication used to treat erectile dysfunction in the country.

And we can see why — it works. Used at the proper dose, Viagra is considered very effective at helping men achieve and maintain an erection and is approved by the Food and Drug Administration for the treatment of ED.

It’s also not a bad thing if you can’t exactly explain how it works. Either way, the famous Pfizer little blue pill can help men aged 18 or older affected by ED to get hard and stay hard when aroused, making sexual activity easier and enhancing sexual performance in general.

But we’re pretty into knowing what we’re putting in our bodies, and we bet you are, too.

So if you’re wondering to yourself “how does Viagra work in the body?” let’s dig a little deeper than “pill makes peen go up,” because although Viagra might seem like an on/off switch for your penis, the way the medication works is fairly complex.

How Viagra Works

Let’s just begin with this very obvious starting question: what does Viagra do? Is it something to do with ball bearings? Quarks? String theory?

Sadly, no. It’s a boring old biological reaction.

Viagra works by inhibiting the enzyme that’s responsible for controlling blood flow in and out of your penis when you’re sexually aroused. Viagra inhibits this phosphodiesterase-5 (PDE5) enzyme — which explains Viagra’s (creatively named) classification as a PDE5 inhibitor.

Now, before we get into this in more detail, it’s important to briefly explain how erectile dysfunction happens and the role PDE5 plays in the process.

Erectile dysfunction, or ED, happens when you get aroused but the PDE5 enzyme stops a sufficient amount of the blood you need to get you hard from flowing into the corpora cavernosa.

Phosphodiesterase type 5 plays a normal role in making the penis flaccid after sex, but in men with erectile dysfunction, PDE5 can make getting erect and staying erect during sex difficult (or impossible). PDE5 is, essentially, number one among the causes of ED.

Viagra then, is the treatment for that cause.

  • By inhibiting PDE5, Viagra makes it easier for blood to flow into the blood vessels in your penis, allowing you to get — and stay — hard during sex.
  • It also reduces the risk of blood flowing back out of your penis during sex, meaning you’re less likely than normal to lose your erection.
  • This makes Viagra (as well as similar medications, such as Cialis® and Levitra®) a highly effective treatment for erectile dysfunction in most men.
  • Other erectile dysfunction medications, such as Cialis and Levitra, also work by inhibiting the PDE5 enzyme.
  • These medications differ from Viagra in how long their effects last — Tadalafil (generic Cialis), for example, can provide relief from erectile dysfunction for as long as 36 hours.

By the way, ED can range in severity — you could find it difficult to get fully erect when you’re sexually aroused but still get a moderate erection. If your ED is severe, your penis might stay entirely flaccid even when you’re aroused, making penetrative sex impossible.

Be sure to seek medical advice from a healthcare professional before you take Viagra and discuss any pre-existing health conditions and any over-the-counter or prescription drugs (such as nitrates) you currently are taking, as these may cause an interaction.

How Long Does it Take for Viagra to Work?

If this is your first time taking Viagra, make sure you plan your sexual activities accordingly — it may not work exactly the way you’ve read online.

Depending on where you got your initial information, the internet suggests that a dose of Viagra could work minutes to hours after taking the pill, and to an extent that’s true. But sticking strictly to the FDA guidelines, Viagra typically kicks in about 30 minutes after you take it, and can work for up to four hours thereafter.

That time frame may be affected by food, your weight, whether you find interesting porn or if your partner does that thing where they run their fingers through your hair.

All we can do is point to the window of effect, and remind you that everyone will have a slightly different experience. Oh, and if you’d like to learn more you can read our blog on how long Viagra lasts.