Viagra (Sildenafil) Dosage - How Much Sildenafil is Too Much?

Sildenafil 100mg tablets and sildenafil 50mg tablets
Written by

Content by

Last Updated

Last Updated

See our range of sildenafil tablets to treat ED

Treatment for Erectile Dysfunction delivered discreetly from our UK Online Pharmacy

Sildenafil is a tablet used to treat Erectile Dysfunction (ED). It works by increasing blood flow to the penis upon sexual arousal, improving ED by helping to achieve and maintain an erection. Sildenafil is the active ingredient in Viagra, and is the non-branded version, more commonly referred to as “generic Viagra”. Essentially, they both work in the same way and in theory, sildenafil is as good as Viagra. The recommended starting dose is one sildenafil 50mg tablet to be taken around one hour before sexual activity. Sildenafil takes around one hour kick in and lasts for up to four hours. It is one of the most commonly prescribed ED treatments, as it has a low side effect profile and is safe to take (provided you have had a consultation with a doctor or pharmacist). You should use the 50mg tablets on eight separate occasions before deciding to increase the dose to sildenafil 100mg if you need to. This should be done on advice of a doctor or pharmacist.

 

Sildenafil dosage

Sildenafil 50mg is the recommended starting dose and you are likely to be prescribed with this dose if you are taking sildenafil for the first time. It is also available over the counter as Viagra Connect, which you can purchase after having a consultation with a pharmacist. Both tablets contain the same active ingredient and are as good as each other. It is important to note that sildenafil does not increase sexual desire, so you will need to be sexually aroused for sildenafil to be effective.

Sildenafil 50mg takes around one hour to take effect, and it can last for up to four hours. Side effects of sildenafil 50mg include headache, dizziness, and indigestion, although not everyone gets them.

Some important points before taking sildenafil 50mg tablets:

  • Ensure to take a tablet one hour before sexual activity, as timing is key. This gives sildenafil enough time to build up in your system.
  • Food can affect the absorption of sildenafil. Heavy meals can delay the absorption of sildenafil, making it less effective. For best results, take a tablet on an empty stomach.
  • A small amount of alcohol is usually safe to consume before you plan on taking sildenafil. However, you should avoid drinking more than 1-2 units of alcohol, as excess alcohol and sildenafil can lower your blood pressure, causing side effects such as dizziness and headache. Too much alcohol can also reduce your ability to achieve and maintain an erection.


Sildenafil 50mg is usually enough to provide the desired effects for most men. If sildenafil 50mg is effective for you, there is no need to increase the dose. Increasing the dose will not improve results if sildenafil is working well for you. Taking more sildenafil than you need can increase the chances of side effects.

 

What should I do if the starting dose of sildenafil did not work?

Sildenafil 50mg is an effective dose and usually enough to have a positive effect on ED. However, if you find that 50mg sildenafil is not working for you, there are a few things to try:

  1. Try taking sildenafil another seven times. UK national guidelines state that you should try taking sildenafil on eight separate occasions, before deciding to increase the dose. Remember, you should not take more than one tablet a day, so you should try taking sildenafil on another day.
  2. Try taking sildenafil on an empty stomach. Food affects the absorption of sildenafil, which means that its effectiveness may be reduced if taken after a heavy meal.
  3. Speak to your doctor or pharmacist about increasing the dose of sildenafil 50mg to 100mg. You should only do this if your doctor or pharmacist instructs you to do so. Taking too much sildenafil can cause unwanted side effects such as headaches, light-headedness, and indigestion.
  4. Avoid alcohol as this can reduce your ability to get an erection.

Important note: If you are experiencing the desired results from sildenafil 50mg tablets, but are experiencing side effects, you should speak to your doctor of pharmacist about taking sildenafil 25mg tablets. Sildenafil 50mg may be too much and you can still benefit from the positive results of treatment at half the dose. This can reduce the likelihood of experiencing side effects.

 

Can I take sildenafil 50mg daily?

You can safely take sildenafil 50mg every day. Remember, sildenafil has a relatively short half-life, which means it exits the body within 6 hours. You will need to take sildenafil around one hour before sexual activity.

 

Can I take two sildenafil 50mg tablets?

You can take two 50mg doses of sildenafil to give you 100mg. You should only do this if your doctor or pharmacist prescribes you with sildenafil 100mg.

 

Increasing the sildenafil dose

Sildenafil 100mg is primarily used to treat ED in those that have limited success with the 50mg dose. Sildenafil 100mg is the highest strength available and can help to provide a higher level of sildenafil in the bloodstream, which may be required if the 50mg dose is not strong enough. Sildenafil 100mg takes around one hour to take effect and will last for around 4 hours. A higher dose of sildenafil does not mean that it will work quicker, or last for longer. However, the effects of sildenafil 100mg can be stronger, which may increase the likelihood of side effects.

You may be prescribed with sildenafil 100mg for the first time by your doctor or pharmacist. Although sildenafil 50mg tablets are more commonly prescribed for first time users, factors such as your body weight, pre-existing medical conditions, medication you may be taking and other lifestyle factors, can influence prescribing decisions. For example, it may not be appropriate to prescribe the highest strength of sildenafil to those with heart problems.

Side effects of sildenafil 100mg may be more pronounced, and can include headache, dizziness, facial flushing, indigestion, stuffy nose, and blurred vision. Side effects usually last for a few hours and are not permanent. Not everyone experiences side effects.

 

What should I do if the maximum dose of sildenafil does not work?

  1. If sildenafil 100mg did not work for you, you should visit your doctor or pharmacist for advice. You will usually be advised to try sildenafil 100mg on eight separate occasions, before deciding on what to do next. Often, sildenafil will become more effective after you try it a few times, as you become comfortable with ED treatment and confident in its ability.
  2. You should try taking sildenafil on an empty stomach, as food can affect the absorption of sildenafil, reducing the amount that it available in your bloodstream. You should also limit your intake of alcohol, as alcohol can reduce your ability to get an erection. Alcohol can also interact with sildenafil, increasing your chances of experiencing side effects.
  3. There are other treatment options available, such as tadalafil and vardenafil. Although they belong to the same group of drugs as sildenafil, known as PDE5 inhibitors, they can prove to be effective for many men who have limited results with sildenafil.

 

Can I take sildenafil 100mg daily?

It is safe to take sildenafil 100mg every day, but this is the maximum dose, and you should not take more than 100mg within 24 hours. Sildenafil has a short-half life of around 3 hours, and it takes around 6 hours for sildenafil to leave your system. This means that you will need to remember to take sildenafil around one hour before you plan to have sex. If you wish to benefit from a daily dose tablet that provides a continuous effect, you should consider using tadalafil.

 

Can I take two sildenafil 100mg tablets?

You should not take two sildenafil 100mg tablets, as this is too much. The maximum licensed dose is 100mg daily and taking more than this can cause serious side effects, such as a drop in blood pressure and priapism, a painful erection lasting longer than four hours. Taking 200mg of sildenafil, or more than you have been prescribed, will not necessarily improve results. It has been proven to significantly increase the chances of experiencing unwanted side effects.

 

How much sildenafil is too much?

Essentially, taking more than than what has been prescribed for you, is too much. The maximum dose is 100mg, and any more than this can cause dangerous side effects such as a drop in blood pressure, headaches, sickness and a stomach upset. Your doctor or pharmacist may have prescribed a lower dose. If this is the case, it is important to follow the instructions you have been given. If you feel that you require a higher dose, it is important to discuss this with your doctor or pharmacist, before deciding to increase the dose yourself. 

 

What sildenafil dose should I take? The Verdict

If you are taking sildenafil for the first time, you should take sildenafil 50mg, providing your doctor or pharmacist has advised that it is safe for you to take. Sildenafil for erectile dysfunction has proven to be effective and has a relatively low side effect profile. If you are experiencing side effects, your doctor or pharmacist may suggest reducing the dose to 25mg. If you are not experiencing significant side effects, and you have tried taking sildenafil 50mg on eight separate occasions with limited results, your doctor or pharmacist may suggest increasing the strength to sildenafil 100mg. For the best results, you should take sildenafil on an empty stomach, and avoid drinking alcohol. Remember, you should try to relax and get yourself in the mood, as sildenafil will only work when you are sexually stimulated.  

Always read the patient information leaflet (pil) before taking sildenafil for erectile dysfunction. You should stop taking sildenafil and seek urgent medical attention if you experience chest pain, loss or decrease in vision, an erection lasting 4 hours or more, seizures or any signs of an allergic reaction. Do not take more than one tablet within 24 hours.


Whilst all of our content is written and reviewed by healthcare professionals, it is not intended to be substituted for or used as medical advice. If you have any questions or concerns about your health, please speak to your doctor.