Sildenafil (generic Viagra) is a treatment for erectile dysfunction (ED). It works in combination with sexual stimulation to help a man gain and maintain an erection for long enough to engage in sexual activity. Sildenafil, like Viagra, comes in 25mg, 50mg and 100mg tablets.
Sildenafil is very effective with at least 2/3 of men reporting an improvement with use, and up to 84% of men reporting improvement in studies using a dose of 100mg. Erectile dysfunction can vary a lot between people and it’s common to trial several doses or several different therapies before finding the one that works best for you. To help you, an ED Trial Pack is available that contains a selection of the most popular ED medications at a range of doses.
Sildenafil, like other medicines in its family (PDE5 inhibitors) works by relaxing the blood vessels that supply the penis. This improves blood flow, making it easier to achieve and maintain an erection when sexually stimulated. Sildenafil should not give you an erection if you are not sexually aroused or excited.
When you first start taking sildenafil, you may not experience effects straight away. It takes 30-60 minutes to absorb and doctors recommend you try sildenafil several times over a period of a few weeks to see if it works for you.
Take ONE tablet 30 to 60 minutes before sexual activity
|Type of medicine||PDE5 inhibitor|
Improved blood flow into the penis
4 to 64 tablets
25mg, 50mg & 100mg
From 94p per dose
Can include headaches, facial flushing, dizziness and nasal congestion
Sildenafil and Viagra are proven to be as effective as one another in treating erectile dysfunction by the UK medicines regulator. While some men will still prefer branded Viagra, Sildenafil is a significantly better value, effective option for ED.
In the UK, most treatments for erectile dysfunction require a prescription, however, Viagra Connect is available over the counter and from our range. Like sildenafil, tadalafil (Cialis) and vardenafil (Levitra) are PDE-5 inhibitors that work by increasing blood flow to the penis in the event of sexual stimulation. Tadalafil (Cialis) lasts significantly longer and can remain effective for 24 to 36 hours.
A common overseas version of sildenafil is Kamagra which is not legal in the UK. It is recommended that you consult a doctor about switching to the legal alternative, Sildenafil.
Like all medications, sildenafil can cause side effects in some, but not all patients. If you experience any of the following serious but rare side effects, stop taking sildenafil and seek medical help immediately:
The most common side effects of sildenafil are headaches which may affect more than 1 in 10 people.
Other common side effects (affecting up to 1 in 10 people) are:
There are other potential side effects that occur infrequently to very rarely, to find out more visit the Sildenafil patient information leaflet.
The most common side effect of sildenafil use is a headache which is reported to occur in more than 10% of users. Headaches can be managed with hydration and over-the-counter painkillers, such as paracetamol or ibuprofen, where necessary. If you experience facial flushing, try and stay cool by applying a cool compress, breathing deeply and trying to relax.
If any side effects are particularly severe or prolonged, or if you frequently experience stomach upset when taking sildenafil, speak to a doctor or pharmacist for advice. A doctor may recommend an alternative ED treatment.
There are some people for which Sildenafil would not be appropriate. These are identified by our doctors when they review your health assessment so ensure you provide accurate information.
It is important that people with the following do NOT take sildenafil:
Allergies to sildenafil or any of the other ingredients
Uncontrolled high or low blood pressure
Unstable heart disease or unstable angina
Severe heart or liver problems
A recent stroke or heart attack
A family history of degenerative eye diseases
Are taking nitrites e.g. for angina
Use “poppers” (butyl nitrate)
Before taking sildenafil, tell your doctor or pharmacist if you are taking any other medications, including those purchased over the counter without a prescription.
Do not take sildenafil along with:
In particular, speak to your doctor if you take:
While sildenafil doesn’t directly interact with alcohol, drinking alcohol can inhibit your ability to get an erection. In order to experience the best results of sildenafil, it is recommended that you limit the amount of alcohol you drink.
Sildenafil should not be taken in combination with other erectile dysfunction medications unless specifically advised by a doctor.
It can be dangerous to take sildenafil with recreational drugs, including stimulants such as ecstasy or cocaine, hallucinogens such as LSD and former-legal highs such as mephedrone.
The following is general advice, always take sildenafil as instructed by a doctor or pharmacist. Swallow one tablet whole with a glass of water approximately an hour before sexual activity. Sildenafil may take longer to work if you have just eaten a heavy or fatty meal.
If you feel that your dose is too weak or too strong, speak to your doctor who may alter your dosage. Do not take sildenafil more than once per day.
The recommended starting dose of sildenafil is 50mg. Your doctor will normally recommend you try this on several occasions over a period of a few weeks.
If you find it is too effective but causing side effects, your doctor may recommend 25mg sildenafil. If you find it’s not working as expected, speak to your doctor who may increase your dose to sildenafil 100mg tablets. Exceeding 100mg daily will not increase its effectiveness, but will increase the risk of side effects.
Sildenafil is safe for long-term use however the underlying cause of the condition should be addressed if possible. Erectile dysfunction often has a psychological or physical cause, such as anxiety, depression, stress, excess weight, poor diabetes control and continued use of treatments such as sildenafil may mask these issues and prevent the patient from pursuing more effective, long-term help.
Sildenafil will not cure erectile dysfunction, the root cause of which is often physical or psychological. Identifying the root cause of your ED and resolving it if possible is the best way to improve ED long term.
There is little evidence to suggest that sildenafil has any effect on female libido or sexual enjoyment and it is not licenced for arousal disorders in women. Speak to your GP about your options for medicines if you are female.
It is safe to buy sildenafil online from a registered pharmacy such as Dr Felix. It is a prescription-only medication and should not be purchased online through any service that is not registered in the UK.
Provided you use a UK registered online service such as Dr Felix that provides a prescription as part of your order, you can buy sildenafil online without a prescription.
Sildenafil takes 30 to 60 minutes to work on average and therefore it is advised to be taken one hour before sexual activity. It is very important to note that Sildenafil works fastest when taken on an empty stomach. If taken on an empty stomach, it is more likely to take effect in 30 minutes. If taken after a heavy meal, allow at least 60 minutes for the sildenafil tablet to work.
Sildenafil typically lasts for 4-6 hours. This does not mean that you will have an erection for this whole time period but rather it will be easier to get and keep one.
The active ingredient in sildenafil is sildenafil citrate.
The inactive ingredients that make up the rest of the tablet are calcium hydrogen phosphate anhydrous, cellulose microcrystalline, croscarmellose sodium, silica colloidal anhydrous, magnesium stearate, lactose monohydrate, hypromellose 15cP, titanium dioxide (E171) and triacetin.
Note that inactive ingredients may differ depending on the manufacturer.
Over the counter treatment
Works in 15-30 minutes
Effective for up to 5 hours
Effective for up to 4 hours
For daily or intermittent use
Sildenafil, Tadalafil, Vardenafil
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