Tadalafil is an erectile dysfunction or impotence medication that works to relax the blood vessels in the penis and support blood flow. The medicine belongs to a group of substances called Phosphodiesterase type 5 inhibitors. More information

A doctor will review your order and write you a prescription, if appropriate. This prescription is then forwarded to a pharmacy. The pharmacy will have your medicine delivered to you within one to three working days. Read more about this process here.

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Tadalafil is the active ingredient of a well-known erectile dysfunction drug called Cialis. It is a treatment designed to treat erectile dysfunction (ED) or impotence in men. Tadalafil belongs to a group of medication called PDE5 or Phosphodiesterase type 5 inhibitors. These substances relax the blood vessels in the penis so that blood can flow more naturally.Tadalafil, combined with sexual stimulation can help to achieve and maintain erectile function in most men. In comparison with other erectile dysfunction treatment, some men find that Tadalafil has a longer-lasting effect.  

What is Tadalafil? 

Tadalafil is an erectile dysfunction or impotence medication that works to relax the blood vessels in the penis and support blood flow. The medicine belongs to a group of substances called Phosphodiesterase type 5 inhibitors. Combined with sexual stimulation, these medications help men to achieve and maintain erectile function over time. Tadalafil is available in two formats. One option is a "daily" pill, which gives the individual the option to always be ready for intercourse. The other option is a 36-hour medication which can be taken half an hour before sexual activity. Because the daily medicine is taken every day it is often given at lower dosages. Depending on your preference and lifestyle, it will often be your choice whether you would prefer to take Tadalafil daily, or 36-hour. However, if you haven't tried taking the treatment before, you may find that it is better to take the lower dose first to see how you react. Discuss your options with your GP.  

When is Tadalafil used? 

Tadalafil is primarily used to treat problems with male impotence and erectile dysfunction. It works alongside sexual stimulation to increase blood flow to the penis. Tadalafil is also used to treat the symptoms of an enlarged prostate in some cases and can address symptoms like difficulty urinating, weak urine stream, and the need to urinate urgently or frequently. Tadalafil is thought to work for prostate issues by relaxing the smooth muscle in the bladder and prostate.  

For ED purposes, Tadalafil absorbs into the body very quickly and is often fast-acting. It allows for sexual intercourse to take place between twenty minutes and one hour after taking a tablet. Tadalafil also requires sexual stimulation to be effective. With Tadalafil daily, it can take up to five days for the treatment to build to its full potential. From that point onwards, the effect of the treatment is consistent. Usually, a single tablet of Tadalafil can stay in the body for 36 hours, as the active ingredient has a longer-lasting effect on the body compared to other treatments for erectile dysfunction. This drug does not protect against sexually transmitted diseases, and it is recommended that users still practice safe sex practices.  

How do you use Tadalafil? 

Depending on your lifestyle, you can choose to use either Tadalafil daily or the 36-hour treatment. Both options contain the same medication, though they often have different dosages, and may be taken in different ways.  

To take the 36-hour treatment, you will need to take one tablet, according to your doctor's instructions, with a glass of water. It is best to take the pill at least thirty minutes to one hour before you plan to be sexually active. Tadalafil can be taken with or without food. However it can take longer to work when you have eaten a heavy meal. To take Tadalafil Daily, take a single tablet with a glass of water at the same time each day. Once again, you can take this substance with or without food, as this will not affect how well it works. It's important to take the substance regularly to ensure you get the full benefit of the medication. Tadalafil must be combined with sexual stimulation to be effective.  

What dosages are available? 

For most men with ED or impotence issues, the recommended starting dose for Tadalafil is 10 mg per day, taken before sexual activity. This is only the dose given for the 36-hour pill. If you're taking the dose daily as part of the Tadalafil Daily treatment, the dosage will be much lower. Depending on the response or side effects that you have when taking Tadalafil, your doctor might increase your dosage to either 20mg for each pill, or 5mg a day. The impact of these pills can last for up to 36 hours, and Tadalafil may last longer than other erectile dysfunction medications.  

Usually, people taking medications that increase blood pressure levels should not exceed a dose of 10mg in 72 hours. Registered doctors can suggest dose adjustments for patients who notice that their erections are lasting for too long, or that they are not getting an erection for long enough. Remember that the maximum dose for Tadalafil Daily is 5mg.  

What are the side effects of Tadalafil? 

For the most part, Tadalafil is a reliable and safe treatment for erectile dysfunction conditions. However, like any medication, side effects are possible. Sometimes, the side effects caused by Tadalafil can vary from person to person.  

The most common side effects are: 

  • Headaches 
  • Muscle aching 
  • Redness or flushing in the face 
  • Back pain 
  • Blocked or stuffy nose 
  • Indigestion 

Back and muscle pain caused by Tadalafil will usually happen between 12 and 24 hours after you've taken the medication. The effects can diminish within 2 days. If your side effects do not go away by themselves, you should contact a doctor or nurse for advice. Some less common side effects can occur in people taking Tadalafil, including: 

  • Feeling tired or dizzy 
  • Vomiting or Nausea 
  • Stomach pain 
  • Blurred vision or eye pain 
  • Blood in the urine 
  • Difficulty breathing 
  • Changes to blood pressure 
  • Swollen feet, ankles, and hands 
  • Nosebleeds, 
  • Ringing in the ears 
  • Chest pain 
  • Allergic reactions 

Prolonged erections may also be a side effect. If you experience an erection for more than four hours when using an ED medication, it's essential to seek emergency help straight away. You should also call an ambulance if you experience any severe side effects, such as priapism, sudden loss of vision, blood from the penis or in the semen, swollen eyelids, memory loss, seizures, fainting, or loss of hearing. 

Very rarely, other side effects have been reported, including temporary loss of vision, migraines, heart attacks, and strokes. Some studies suggest that higher dosages of Tadalafil may increase your chances of more severe and longer-lasting side effects. This is one of the reasons why it is important to make sure that you discuss your dosage carefully with your doctor before taking Tadalafil.  

When shouldn't you use Tadalafil? 

Before you begin taking Tadalafil, tell your doctor or pharmacist if you're allergic to the substance, or you know of any other allergies that you might have. The product may sometimes include inactive ingredients which can cause allergies to flare up. It's also important to talk to your doctor and tell them about your general medical history before taking Tadalafil; this is particularly crucial if you have a history of any heart problems, including heart attacks or life threatening conditions. Let your doctor know if you have had angina or an irregular heart-rate in the last 6 months, or if you've suffered from kidney disease, liver disease, low or high blood pressure, and more.  

Penis conditions are also important to inform your doctor about before taking Tadalafil. If you have suffered from Peyronie's disease, have a history of painful or prolonged erections, or have conditions that may increase your risk of priapism, let your doctor know. Bleeding disorders and active stomach ulcers may also make it more dangerous for some people to take Tadalafil. Keep in mind that in some people, Tadalafil can cause dizziness, marijuana use, or alcohol can worsen this experience, and it's not recommended to drive or use machinery unless you're sure that you can do it safely. Limit your intake of alcoholic beverages, and speak to your doctor if you're a drinker, or you're using any herbal substances.  

Does Tadalafil interact with any other medications? 

There are various medications that may interact negatively with Tadalafil. It's important to discuss these medications with your doctor before taking this medicine. If your doctor is aware that you're taking a medicine that may interact with Tadalafil, then they will have already weighed the risks of using the substance accordingly.  The elimination and removal of Tadalafil from the body can be decreased by substances like itraconazole, indinavir, and erythromycin. As such, these drugs may mean that you have more Tadalafil in the blood at any period. The dose should usually be reduced when taking these drugs simultaneously to reduce the risk of negative side effects.  

Alternatively, carbamazepine, Rifampin, Phenytoin, and Phenobarbital can decrease the blood levels of Tadalafil, and therefore reduce its potency. Tadalafil may exaggerate the effects of blood pressure medications like nitrates. It can also enhance the effects of substances that are frequently used for treating heart pain or angina. Patients taking nitrates can have an increased risk of chest pain or heart attack with Tadalafil. This medication also increases the blood pressure reducing effects of some drugs for alpha-blocking purposes. Individuals taking alpha-blockers must always be on a stable dose of their medicine before treatment with Tadalafil is started. Most doctors also recommend starting medication on the lowest dose for people using alpha blockers.  

Crucially, both alcohol and Tadalafil lower blood pressure, which means that it's usually not a good idea to combine the two substances. Combining Tadalafil with alcohol can increase heart rate and cause dizziness and headaches. PDE5 substances like Tadalafil can also affect platelet function and prolong bleeding, so it must not be used in patients with bleeding disorders without extreme caution.  

Where can you buy Tadalafil? 

Tadalafil is available from online and offline pharmacies in the UK after a prescription has been given. It is important to get a prescription and a complete medical check before purchasing Tadalafil, as different people will need specific dosages.  

Tadalafil may also be sold under the brand-name Cialis. The generic form of Tadalafil became generally available in the UK in 2017. Before this time, the drug was only available via Cialis.  

Can you get Tadalafil without a prescription?  

It is essential to get a full medical check and a prescription for Tadalafil, as the substance can be dangerous when used incorrectly. You will be required to fill out a medical questionnaire or discuss your condition with a doctor before your treatment is approved.  




Clin Interv Aging, 2006, Tadalafil in the treatment of erectile dysfunction; an overview of the clinical evidence, Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2699638/  

Taylor, John et al., 27th of April 2009, West Yorkshire, Differences in side‐effect duration and related bother levels between phosphodiesterase type 5 inhibitors, retrieved from https://onlinelibrary.wiley.com/doi/full/10.1111/j.1464-410X.2008.08328.x 

Pak J Pharm Sci, 2008, Effectiveness of sildenafil citrate (Viagra) and tadalafil (Cialis) on sexual responses in Saudi men with erectile dysfunction in routine clinical practice, Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/18614424 

Assessed by:

Dr Wouter Mol, General practitioner
Registration number: BIG: 9057675501

Dr Wouter Mol studied medicine at the University of Groningen. From 2002 to 2003, he served as a resident in neurology, and from 2003 to 2005 he served his residency training in internal medicine and emergency medicine. Wouter Mol has been working as a GP since 2005.