It's also sometimes used to treat pulmonary hypertension (high blood pressure in the blood vessels that supply the lungs).
Tadalafil is available on prescription only.
It comes as tablets that you swallow with water. It can be taken with or without food.
- It usually takes 30 to 60 minutes for tadalafil to work for erectile dysfunction. You can take it once a day, at least 30 minutes before you want to have sex.
- Taking tadalafil on its own is not enough to cause an erection. You need to be sexually aroused for it to work.
- Many men do not have any side effects from tadalafil, while some have mild side effects. These may include headaches, back pain, muscle aches, pain in your arms and legs, facial flushes, stuffy nose, and indigestion.
- Do not take tadalafil if you also take medicines called nitrates (often prescribed for chest pain). This combination can cause dangerously low blood pressure.
- Tadalafil is sometimes called the brand names Cialis (for erectile dysfunction and benign prostatic enlargement) or Adcirca (for pulmonary hypertension).
Who can and cannot take tadalafil
Tadalafil can only be taken by adults aged 18 and over.
Tadalafil is not suitable for some people.
Do not take tadalafil if you:
- have had an allergic reaction to tadalafil or any other medicines in the past
- are taking medicines called nitrates for chest pain
- have a serious heart and liver problem
- have recently had a stroke or a heart attack
- have low blood pressure or uncontrolled high blood pressure
- have ever lost your vision due to reduced blood flow to the eye
Check with your doctor before taking tadalafil if you:
- have sickle cell anaemia (an abnormality of red blood cells), leukaemia (cancer of blood cells) or multiple myeloma (cancer of bone marrow)
- have Peyronie's disease (curved penis) or a similar problem with your penis
- have liver or kidneys problems
- have a heart problem – your doctor will advise you whether your heart can take the additional strain of having sex
Where to get tadalafil
Tadalafil is only available with a prescription.
On the NHS
You can get tadalafil on the NHS if you have erectile dysfunction, benign prostatic enlargement or pulmonary hypertension.
The branded versions of tadalafil, such as Cialis, are not available on the NHS, except in special circumstances.
You can also get tadalafil on a private prescription from a doctor. This means you'll need to pay the full cost of the medicine.
How and when to take it
It's important to take this medicine as advised by a doctor or pharmacist.
Tadalafil tablets come in different strengths.
Swallow your tablets whole, with a drink of water. The tablets can be taken with or without food.
How much will I take for erectile dysfunction?
You usually take tadalafil before having sex. Take 1 tablet at least 30 minutes before you want to have sex. Do not take more than 1 tablet a day.
The usual dose is 10mg. Your doctor may increase or decrease your dose, depending on how well it works and how often you take it.
The effects may last longer than 24 hours, so you're not recommended to take the 10mg or 20mg tablets every day.
For the tablet to work properly, you’ll need to be sexually excited.
If you have a private prescription for tadalafil, read the information that comes with your medicine carefully. The strength and dosage instructions can vary.
How much will I take for benign prostate enlargement?
Tadalafil tablets for an enlarged prostate come as 2.5mg or 5mg. The usual dose is 5mg, taken once a day.
You can take your tablet in the morning or evening, but it’s best to take it at the same time each day.
Your doctor might give you a low dose of 2.5mg if you are having any problems, such as side effects.
If you are being treated for both benign prostatic enlargement and erectile dysfunction, the dose is 5mg.
How much will I take for pulmonary hypertension?
Tadalafil tablets for pulmonary hypertension come in 20mg strength.
The usual dose is 40mg – two 20mg tablets, taken once a day. These tablets are large, so take the tablets one after the other.
If you have kidney or liver problems your doctor might decrease the starting dose to 10mg or 20mg.
What if I forget to take it?
If you have:
- benign prostatic enlargement – take it as soon as you remember and then continue as usual
- pulmonary hypertension – take it within 8 hours if you can. If you remember after 8 hours, skip the missed dose and take the next dose as usual.
Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
If you often forget doses, it may help to set an alarm to remind you.
You could also ask a pharmacist for advice on other ways to help you remember to take your medicine.
What if I take too much?
Taking too much tadalafil by accident can cause unpleasant side effects, including:
- stuffy nose
- problems with your vision (such as blurred vision)
Side effects will usually go away when you stop taking the tablets. Talk to a doctor if you have taken too much tadalafil and you're worried about these side effects.
Like all medicines, tadalafil can cause side effects in some people. Many people have no side effects or only minor ones.
Common side effects
Common side effects happen in more than 1 in 100 people. The side effects may increase with an increasing dose.
If you get these side effects, keep taking the medicine, but tell a doctor or pharmacist if they bother you or do not go away:
- feeling sick (nausea)
- red or flushed face
- stuffy nose
- muscle aches
Serious side effects
Serious side effects are rare and happen in less than 1 in 1,000 people.
Stop taking tadalafil and call a doctor straight away if you get:
- chest pains – if this happens during or after sex, get into a semi-sitting position and try to relax (remember do not use nitrates for chest pain while taking tadalafil)
- prolonged and sometimes painful erections – if you have an erection that lasts for more than 4 hours, contact a doctor immediately
- a sudden problem with your eyesight or hearing
- a serious skin reaction – symptoms may include red raised patches on your skin or red spots (hives), a swollen face and swelling around the eyes
- seizures or fits
These are not all the side effects of tadalafil. For a full list, see the leaflet inside your medicine packet.
You can report any suspected side effect to the UK safety scheme.
Pregnancy and breastfeeding
Women with pulmonary hypertension may be treated with tadalfil.
If you have pulmonary hypertension, tadalafil is not recommended in pregnancy or while breastfeeding.
Tell your doctor if you're:
- trying to get pregnant
Caution with other medicines
Some medicines do not mix well with tadalafil.
Tell a doctor if you're taking these medicines before you start tadalafil:
- nitrates for chest pain
- riociguat for pulmonary hypertension
Mixing tadalafil with herbal remedies and supplements
Some complementary therapies may have ingredients that could interfere with tadalafil and cause side effects.
Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.