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Cialis (Tadalafil) Side Effects

In 30 seconds…

Tadalafil (known by the brand name Cialis) is an effective treatment for erectile dysfunction, but some people do experience side effects.  

Most side effects are easily manageable and are the result of vasodilation. This is what causes increased blood flow for an erection — but it can also relax blood vessels elsewhere in the body. 

To lower your risks of side effects, start with a smaller dose and scale up slowly if required.

Taking Cialis can definitely help heat up your bedroom antics, but it’s important to be aware of its possible side effects, so you don’t land yourself in proverbial hot water. 

While most side effects of Cialis or Tadalafil are harmless, the same mechanism that makes it a popular (and effective) treatment for erectile dysfunction (ED) make it inadvisable for a minority of people.

The active ingredient in Cialis and Tadalafil affects your blood pressure, which is completely harmless to most of us — but you should know if and when to avoid it so you can be confident you’re safe.

What Happens When You Take Cialis or Tadalafil?

What is Tadalafil or Cialis — and how does it work? The first thing to know is that Tadalafil and Cialis are the same: Cialis is the brand name for Tadalafil. This is similar to Sildenafil (and the branded drug, Viagra). The main difference is Cialis lasts longer.

Approved by both the FDA and MHRA, Cialis works by supporting the way your body naturally gets an erection. When you become erect, the arteries in your penis relax and open up, which allows more blood to flow in. 

This increased blood flow causes your penis to get larger and harder. Cialis helps set off this chain reaction by allowing your blood vessels to relax — meaning as soon as you’re aroused by sexual stimulation, your erection starts to kick in. 

A PDE5 Inhibitor

Cialis is what’s known as a phosphodiesterase-5 (PDE5) inhibitor, which means it prevents a specific enzyme in your blood vessels from working, causing them to relax. Depending on the dose, it usually takes 30 to 60 minutes for Cialis to work for erectile dysfunction. 

You can take it once a day, ideally at least 30 minutes before sexual activity.

The main thing to note is that Cialis acts on blood vessels, as PDE5 is found in the blood vessels throughout the body. So, while the most obvious effect you’ll see is in your penis, blood vessels will also be relaxing elsewhere. Normally this isn’t visible (or even noticeable) but it can cause some side effects. 

What Are the Common Side Effects of Cialis (Tadalafil)?

Not all side effects are equal. The common side effects of Cialis are insignificant, but you should be aware of the rarer, more serious side effects, just in case. 

  • The most common side effect is a mild headache. This happens to about 11% of men who take Cialis. Eating a small meal about an hour before ingesting the tablet can help, but avoid fatty foods as this inhibits Cialis’ effectiveness. It’s also safe to take a small dose of over-the-counter pain medication such as paracetamol if you feel a headache coming on.
  • The next most common side effect is dyspepsia — i.e. indigestion. This affects less than one in ten men taking Cialis. If you have stomach trouble after taking Cialis, you may find eating light meals or sipping a flat ginger beer helps. The feeling should pass with the effects of the medicine, so you don’t need to worry about prolonged indigestion problems. 
  • Another possible side effect is dizziness. When Cialis relaxes your blood vessels, it lowers your blood pressure. This sudden decrease can occasionally lead to that head-rush feeling of standing up too quickly. Any dizziness will also pass with the effects of the medication, but it does help to be sensible with alcohol consumption. Most men find they can drink a glass or two, but drinking more can make you increasingly dizzy.
  • Some men also experience back pain or muscle pain (myalgia) when taking Cialis. These usually come on between 12 and 24 hours after taking the tablet and go away by themselves within 48 hours. 
  • A few men get a stuffy nose when they take ED medication. Again, the culprit is vasodilation, as the opening of capillaries can create a feeling of congestion in your nose. It’s superficial and passes. Just make sure you’re otherwise breathing freely. 
  • Finally, a purely cosmetic side effect is facial flushing. If you blush easily, you might be in the small minority of men who experience this with Cialis. It feels no different to a flush after exercise, and yet again vasodilation is to blame. If it bothers you, sit tight — it’ll reduce after the period of maximum effect for the medication. 

Remember: These side effects don’t happen all of the time, and they’re also commonly experienced through completely unconnected circumstances (like exercise, getting up too quickly or a common cold). It might not be Cialis causing them, but if you suspect it is, you should consult Manual’s clinicians.

Are There Serious Side Effects of Tadalafil?

Some people are allergic to Cialis (Tadalafil), but this is rare. If you are one of these unlucky few, or if you suffer from a painful or prolonged erection (this is called priapism), consult a health care professional immediately.

It’s also important to note that Cialis’ effect on your cardiovascular system can make it dangerous for some people. Anyone with heart disease, heart problems, or taking medication for high blood pressure should be especially careful because Cialis can amplify the effects of organic nitrates, which are commonly used to treat heart conditions. 

A test on healthy men who were given a mix of a PDE5 inhibitor (like Cialis) with a nitrate medication saw blood pressure drop by 25–51 mm Hg, which is potentially dangerous and can cause fainting, heart attack, or a stroke.

Like any medicine, there are some rare possibilities you shouldn’t ignore. If you experience any loss of vision or chest pain, you should seek medical help. Similarly, you should see a doctor if you have any hearing loss. Think of this as the medical equivalent of knowing where the fire escape is in your building. It’s not expected, but you need to know what to do just in case. 

For comprehensive guidance, always read the leaflet that comes with your medication.

Who Can and Cannot Take Cialis for Erectile Dysfunction?

Cialis can only be taken by adults aged 18 and over. You should not take Cialis if you have previously experienced an allergic reaction to Cialis or Tadalafil. 

As noted above, Cialis affects blood vessels throughout the body. You should avoid it if you are taking prescription drugs for chest pain. And if you have liver disease or kidney disease; have suffered a stroke or heart attack; have low blood pressure or uncontrolled high blood pressure, or have ever experienced vision loss due to reduced blood flow to your eye, you should speak to your healthcare professional before taking it. 

It’s also important to check with your doctor before taking Cialis if you have Peyronie’s disease (a curved penis) or a similar problem with your penis, or have blood-related conditions such as sickle cell anaemia, leukaemia, or multiple myeloma. 

Don’t mix Cialis with recreational drugs; especially poppers. Poppers contain amyl nitrate or amyl nitrite, and, as we discussed above, nitrates and Cialis are not a good combination. Similarly, drinking too much when taking Cialis can lower your blood pressure. 

Men taking erythromycin, certain antifungal and anti-HIV medications should use Cialis in low doses.

Lastly — and most randomly — try and avoid drinking copious amounts of grapefruit juice. This decreases your gut’s ability to process Cialis.

How Long Do the Side Effects of Cialis (Tadalafil) Last?

Side effects usually last for as long as the medicine is effective. Sometimes they kick in a little while after Cialis affects your penis, and sometimes they wear off before Cialis has passed out of your body. 

There are no common side effects which last longer than 24 hours after Cialis has worn off, and most subside with the effective period of the medicine. 

If any side effects last longer than the maximum effectiveness time for the medicine, it’s time to check-in with your doctor.

Cialis (Tadalafil)

The weekend pill

Known as the “weekend pill” because it is effective for up to 36 hours, Tadalafil is the generic, unbranded version of Cialis. Clinically proven to help you get an erection when you need it.


Best for
Weekend use
Effective in
Effective in 8 out of 10 men
Dosage
2.5mg, 10mg, 20mg

Key Takeaways: Is It Safe to Use Cialis?

Cialis (Tadalafil) is an MHRA- and FDA-approved medicine for the management of erectile dysfunction, meaning the British and American medical drug authorities have signed off on its safety when taken in line with medical advice. 

The side effects of Cialis are usually only something to worry about if you have another serious medical condition, such as having had a stroke or a heart attack within the past six months. 

Be straightforward with your healthcare professional about your health history and other medications — it’s important to answer all medical questionnaires accurately. 

Proceed with confidence, but if you’re in any doubt at all, seek expert medical help or consult the clinicians at Manual.

References

  1. MedicineNet -Cialis vs. Viagra: https://www.medicinenet.com/cialis_vs_viagra/article.htm#what_are_the_side_effects_of_cialis_and_viagra

  2. phauk.org -Phosphodiesterase 5 inhibitors: https://www.phauk.org/treatment-for-pulmonary-hypertension/phosphodiesterase-5-inhibitors

  3. NHS -Tadalafil: https://www.nhs.uk/medicines/tadalafil/

  4. U.S. National Library of Medicine -Tadalafil: https://medlineplus.gov/druginfo/meds/a604008.html

  5. U.S. Food and Drug Administration -Questions and Answers for Cialis (tadalafil): https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/questions-and-answers-cialis-tadalafil

  6. Harvard Health Publishing -Are erectile dysfunction pills safe for men with heart disease?: https://www.health.harvard.edu/mens-health/are-erectile-dysfunction-pills-safe-for-men-with-heart-disease

  7. Drugs.com -Drug Interactions between Cialis and grapefruit: https://www.drugs.com/drug-interactions/cialis-with-grapefruit-2144-1395-2624-0.html

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

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