Short answer: Tadalafil (Cialis) taken when needed comes as 10mg or 20mg, taken at least 30 minutes before sex: the usual dose is 10mg, and 20mg may be tried if 10mg does not work well enough (Cialis product information, SmPC section 4.2). The maximum is one tablet in 24 hours, so never more than 20mg a day, and our advice is: Take one tablet no more than twice a week, and never more than once in 24 hours. Daily tadalafil is a lower dose, usually 5mg, or 2.5mg for some men. Take one tablet a day, at about the same time each day. It is for men who expect to have sex at least twice a week. With a liver problem we supply no more than 10mg when needed and no daily tadalafil, an alpha-blocker changes which form we can offer, and a GPhC-registered pharmacist decides your dose.
This guide sets out what the UK product information for Cialis and generic tadalafil and the NHS say about the dose, as of October 2026, and how our consultation applies it. We supply tadalafil for erectile dysfunction only. If you have urinary symptoms, please see your GP.
What doses of tadalafil are there?
Tadalafil for erectile dysfunction comes in four strengths: 10mg and 20mg to take when needed, and 2.5mg and 5mg to take once a day (Cialis SmPC, section 4.2). These are the doses we supply:
| Dose | How it is taken | Who it may suit |
|---|---|---|
| 10mg, taken when needed | At least 30 minutes before sex. Take one tablet no more than twice a week, and never more than once in 24 hours. | The usual starting dose (SmPC 4.2). The most we supply with a liver problem, or with erythromycin, aprepitant, diltiazem, fluconazole or verapamil. |
| 20mg, taken when needed | At least 30 minutes before sex. Take one tablet no more than twice a week, and never more than once in 24 hours. | If 10mg does not work well enough (SmPC 4.2): at a repeat order when 10mg caused no side effects, or if you have taken 20mg before, from your GP or another pharmacy, and it worked for you without side effects. Our pharmacist will check this with you. |
| 2.5mg, daily | Take one tablet a day, at about the same time each day. | If 5mg is not well tolerated (SmPC 4.2). The starting dose if you take an alpha-blocker other than doxazosin, and the most we supply if you take erythromycin, aprepitant, diltiazem, fluconazole or verapamil. |
| 5mg, daily | Take one tablet a day, at about the same time each day. | The usual daily dose (SmPC 4.2). It is for men who expect to have sex at least twice a week. |
The pharmacist decides your dose. A first order is usually for the starting dose, or a lower one if your answers call for it. When you reorder, we ask how your last tablets worked and whether you had any side effects: if your dose did not work well enough and caused no side effects, the pharmacist can consider the next strength up. If you switch between the two forms of tadalafil, or from another medicine, you start at the new one's starting dose.
Sildenafil (Viagra) has its own doses: see sildenafil dosage, or all our erectile dysfunction treatments.
What is the maximum dose of tadalafil in 24 hours?
One tablet, and no more than 20mg: the UK product information says tadalafil can be taken at most once a day, and 20mg is its highest dose for erectile dysfunction (Cialis SmPC, section 4.2).
For tadalafil taken when needed, our limit is also twice a week (below). Daily tadalafil is one tablet a day, so its maximum is 5mg a day.
For some men the maximum is lower. With any liver disease or reduced liver function, or if you take erythromycin, aprepitant, diltiazem, fluconazole or verapamil, the most we supply is 10mg: the product information has no data on doses above 10mg with liver problems (SmPC 4.2), and medicines that block the enzyme that breaks tadalafil down (CYP3A4), such as erythromycin, can be expected to raise the amount in the blood (SmPC 4.5).
Never take more than your dose: the NHS says taking an extra dose of tadalafil can be dangerous, and to get help from NHS 111 if you have taken more than your prescribed dose. Headache, indigestion, back pain and muscle aches become more common as the dose goes up (SmPC 4.8): see tadalafil side effects.
How often can you take Cialis?
Take one tablet no more than twice a week, and never more than once in 24 hours. That is our advice for tadalafil taken when needed. Daily tadalafil is one tablet a day.
The product information's own limit is once a day (Cialis SmPC, section 4.2), and for frequent use it describes a once-daily lower dose instead. So our consultation offers the two forms by how often you expect to need treatment:
- Less than twice a week: tadalafil taken when needed, 10mg or 20mg. Daily tadalafil is not offered.
- About twice a week: either form may suit, taken when needed or daily.
- More than twice a week: the consultation shows daily tadalafil first, and tadalafil taken when needed is not offered.
How do you take tadalafil?
Swallow one tablet whole with some water: at least 30 minutes before sex if you take it when needed, or at about the same time each day if you take it daily (Cialis SmPC, section 4.2; NHS). For tadalafil taken when needed:
Take it at least 30 minutes before sex. It takes about 30 to 45 minutes to work, and its effect can last more than 24 hours.
Food and drink. Tadalafil is not affected by food. Avoid grapefruit juice.
You still need to be aroused. These tablets only work with sexual stimulation.
How do you take daily tadalafil?
Take one tablet a day, at about the same time each day. You take it whether or not you plan to have sex that day. The product information found that taking tadalafil in the morning or the evening made no clinically relevant difference to how it is absorbed (SmPC 5.2), so choose a time you will remember.
If you forget a dose, the NHS advises taking it as soon as you remember, unless it is nearly time for your next one, in which case skip the missed dose. Never take two doses to make up for a forgotten one. How long tadalafil takes to work and how long it lasts are in how long does tadalafil last.
Should you take tadalafil daily or when needed?
It depends mainly on how often you have sex: daily tadalafil is for men who expect to have sex at least twice a week, and tadalafil taken when needed for up to twice a week (Cialis SmPC, section 4.2, and our consultation's rules).
The two ways to take tadalafil
- Tadalafil taken when needed: 10mg or 20mgTake it at least 30 minutes before sex. It takes about 30 to 45 minutes to work, and its effect can last more than 24 hours. Take one tablet no more than twice a week, and never more than once in 24 hours.
- Daily tadalafil: 2.5mg or 5mgTake one tablet a day, at about the same time each day. It is for men who expect to have sex at least twice a week.
The available data does not suggest that taking it every day works better than taking tadalafil when needed.
The product information says continued daily use should be reassessed from time to time (SmPC 4.2): a review is needed every 6 to 12 months if you carry on.
- Not offered if: you have any liver or kidney disease, or you take doxazosin.
- Blood pressure medicines: if you take them, tadalafil can lower your blood pressure further. If you feel dizzy or sick, see your GP to review your blood pressure medicine.
- GP notification. Daily tadalafil should be added to your regular medication record. We will contact your GP with your consent, or you can tell them yourself. Will you tell my GP?
How tadalafil compares with sildenafil, vardenafil and avanafil is in sildenafil vs tadalafil.
Not sure which suits you? Answer a few questions about your health and the medicines you take. A GPhC-registered pharmacist reviews every consultation, and if they cannot approve your order, we refund you in full.
Start your consultationCan I take 10mg of Cialis daily, or two 5mg tablets at once?
No: 10mg is a dose for before sex, not for every day, and daily tadalafil is one 5mg or 2.5mg tablet a day, never two at once. The UK product information says: "Tadalafil 10 and 20 mg is intended for use prior to anticipated sexual activity and it is not recommended for continuous daily use." (Cialis SmPC, section 4.2.) For daily use it sets a lower dose, 5mg once a day at about the same time, which can be lowered to 2.5mg if 5mg is not well tolerated. More on our daily tadalafil page.
Two 5mg tablets make 10mg, a dose the product information says is for use before sex, not every day. The NHS says not to take more than 1 dose a day, so never add a 10mg or 20mg tablet to your daily tablet either.
If your daily dose does not seem to be working well enough, tell us before your next order rather than taking more. The product information also says tadalafil should not be taken with another erectile dysfunction medicine (SmPC 4.4).
Who starts on a lower dose of tadalafil?
You start lower, have a lower limit, or cannot have one of the two forms if you take an alpha-blocker or erythromycin, aprepitant, diltiazem, fluconazole or verapamil, or if you have a liver or kidney problem. Age alone does not lower the dose: the product information says no dose change is needed for older men, or for men with diabetes (Cialis SmPC, section 4.2). This is how our consultation applies it:
| If this applies to you | Tadalafil taken when needed (10mg, 20mg) | Daily tadalafil (2.5mg, 5mg) |
|---|---|---|
| Doxazosin | Not offered | Not offered |
| Another alpha-blocker, such as tamsulosin or alfuzosin | Not offered | Starts at 2.5mg, once your alpha-blocker dose has stayed the same recently, without dizziness or fainting |
| Erythromycin, aprepitant, diltiazem, fluconazole or verapamil | 10mg at most | 2.5mg |
| Any liver disease or reduced liver function | 10mg at most, unless it is severe (below) | Not offered |
| Any kidney disease or reduced kidney function | The usual doses, unless it is severe (below) | Not offered |
| Severe liver impairment | Not offered | Not offered |
| Severe kidney failure, eGFR under 30, or dialysis | Not offered | Not offered |
| An HIV protease inhibitor (atazanavir, darunavir, ritonavir, fosamprenavir, lopinavir, saquinavir or tipranavir) | Not offered | Not offered |
| Ketoconazole, itraconazole, voriconazole or clarithromycin | Not offered | Not offered |
| Rifampicin, phenobarbital, phenytoin, carbamazepine or St John's Wort | Not offered | Not offered |
Why, from the product information: with an alpha-blocker, tadalafil can cause low blood pressure with symptoms in some men, the combination with doxazosin is not recommended, and with any alpha-blocker treatment should start at a minimal dose and be adjusted gradually (SmPC 4.4 and 4.5). Rifampicin lowers the amount of tadalafil in the blood, which can be expected to make it work less well, and some epilepsy medicines may lower it too (SmPC 4.5). Daily dosing has not been evaluated with liver problems and is not recommended with severe kidney problems (SmPC 4.2).
How do you get the most from Cialis?
Take it at the right time, make sure you are aroused, keep alcohol light and give it several tries, and never take more than your dose.
- Timing. Take it at least 30 minutes before sex.
- Arousal. These tablets only work with sexual stimulation.
- Alcohol. Drinking less alcohol can help your erections. With tadalafil, alcohol can also make low blood pressure more likely, which can make you feel dizzy or light-headed (NHS).
- Other medicines. Tell us every medicine you take: some can make tadalafil work less well (SmPC 4.5).
- Several tries. Try a tablet 4 to 8 times before deciding it does not work, then tell us.
If 10mg did not work well enough and caused no side effects, say so when you reorder: the pharmacist can consider 20mg, unless a liver problem or a medicine such as erythromycin keeps you at 10mg. If a medicine has not worked after 4 to 8 tries at the highest dose that suits you, your pharmacist may suggest trying a different one. If it is sildenafil that is not working, see Viagra not working.
Losing weight, stopping smoking, drinking less alcohol and exercising can all help. If you cycle more than 3 hours a week, try a break from cycling.
How much tadalafil can you get, and what does it cost?
Tadalafil taken when needed comes in packs of 4 or 8 tablets (maximum 8 tablets per 4 weeks), and daily tadalafil as 28 tablets on a first supply, up to 56 on later supplies. Our prices, as of October 2026:
| Treatment | Pack | Price |
|---|---|---|
| Tadalafil 10mg, taken when needed | 4 tablets | £4.00 |
| Tadalafil 10mg, taken when needed | 8 tablets | £7.99 |
| Tadalafil 20mg, taken when needed | 4 tablets | £5.00 |
| Tadalafil 20mg, taken when needed | 8 tablets | £9.99 |
| Daily tadalafil 2.5mg | 28 tablets | £23.99 |
| Daily tadalafil 2.5mg | 56 tablets (later supplies) | £44.99 |
| Daily tadalafil 5mg | 28 tablets | £24.99 |
| Daily tadalafil 5mg | 56 tablets (later supplies) | £45.99 |
| Cialis Together 10mg (pharmacy medicine) | 4 tablets | £18.99 |
| Cialis Together 10mg (pharmacy medicine) | 8 tablets | £28.99 |
Free tracked delivery on every order. The consultation is free. Supplied only if your pharmacist decides it is suitable for you.
Tadalafil is the active ingredient in Cialis, and the tadalafil we supply is a generic version. Generic tadalafil tablets contain the same active ingredient at the same strength and are licensed in the UK. The pack shows the medicine's name and the name of the company that makes it, instead of the brand name. Your order comes in plain packaging, with no medicine names on it. Is the packaging discreet?
What is the dose of Cialis Together?
One 10mg tablet, at least 30 minutes before sex, and no more than one tablet a day (Cialis Together product information, SmPC section 4.2, and its leaflet, section 3).
Cialis Together contains tadalafil 10mg, the same active ingredient as prescription Cialis. It is a pharmacy medicine, supplied after a pharmacist consultation with no prescription needed, to men aged 18 to 64: a short pharmacy checklist that our pharmacist reviews before your order is sent.
It is not for continuous daily use. Its product information says men who use it at least twice a week should talk to their doctor about whether a once-daily lower dose of tadalafil would be more suitable (SmPC 4.2). If you use it that often, our checklist says: Cialis Together is not for frequent use. Please see your GP, or start our full consultation to ask about a daily treatment.
With an alpha-blocker, or a medicine such as erythromycin or clarithromycin, its product information says to consult a doctor first, as a lower daily dose of 2.5mg or 5mg may be more suitable (SmPC 4.2). Our checklist then asks you not to order it, and to see your GP or start our full consultation, where our pharmacist checks whether a prescription treatment is safe for you.
Erection problems can be an early sign of heart disease, diabetes or high blood pressure. Please book a check-up with your GP as soon as you can, within 6 months of starting Cialis Together. Less common side effects are listed in the leaflet in your pack. Please read it before your first dose.