Sildenafil also known as generic sildenafil or generic Viagra is a medicine indicated to treat erectile dysfunction.

Buy sildenafil tablets online from DrFelix online doctor & pharmacy without any appointments to see your doctor. Sildenafil tablets are only available on prescription; our doctors can issue a prescription for sildenafil online.

Your sildenafil tablets will be posted in plain & discreet packaging with no indication of contents inside. DrFelix also offers other popular ED medicines like the branded Viagra, Levitra and Cialis.

Complete a short consultation before selecting your medication. All our consultations are approved by a UK Medical Doctor.

Summary of available medications

Medication Quantity Price
Sildenafil 25mg 4 to 16 tablets From £7.85
Sildenafil 50mg 4 to 16 tablets From £8.45
Sildenafil 100mg 4 to 16 tablets From £8.95

All medications


Medication Quantity Price
Sildenafil 25mg 4 tablets £7.85
Sildenafil 25mg 8 tablets £13.95
Sildenafil 25mg 16 tablets £23.95
Medication Quantity Price
Sildenafil 50mg 4 tablets £8.45
Sildenafil 50mg 8 tablets £15.45
Sildenafil 50mg 16 tablets £25.95
Medication Quantity Price
Sildenafil 100mg 4 tablets £8.95
Sildenafil 100mg 8 tablets £16.95
Sildenafil 100mg 16 tablets £27.95

All prices exclude prescription fee

Sildenafil (the generic version of the erectile dysfunction treatment more commonly known as Viagra) has revolutionised the way ED is treated around the world. It’s effectiveness, combined with the few side effects associated with the treatment, is the main reason for its popularity. Following the end of the UK patent protection on Viagra, cheaper generic versions of the drug are now available. The active ingredient is sildenafil citrate, a PDE5 inhibitor. Sildenafil works by inhibiting an enzyme which regulates the blood flow to the penis, which in turn increases the blood flow to the area and multiplies sexual stimulation. PDE5 inhibitors like sildenafil tablets use natural arousal as a trigger to help achieve and maintain an erection.

What Causes Erectile Dysfunction?

There are a range of medical and lifestyle issues which can lead to ED. Common health-related causes include diabetes and heart disease, while common lifestyle issues like smoking, excess alcohol consumption, obesity and stress can cause problems. Those with issues should schedule an appointment with their GP to have the potential causes investigated.

Why Choose Sildenafil?

Viagra and generic Sildenafil are well-known and widely used treatments for erectile dysfunction, and they are highly effective for many people. The side effects are fairly uncommon, and the action of the treatment tends to be consistent and reliable. While other treatments like Levitra and Spedra are also effective, Sildenafil is one of the most widely prescribed. The drug takes effect fairly quickly, usually within an hour of being consumed, after which it should help achieve and maintain an erection for up to 6 hours. These times can be influenced by various factors, including the amount of food or alcohol consumed during the time beforehand. Ideally it should be taken without food (or with a small meal) and without alcohol in the system.

How Effective Is Sildenafil?

Like most medications, Sildenafil may not work for everyone. The success will depend on the underlying cause of the erectile dysfunction, and the treatment will require:
  • Sufficient blood supply to the penis
  • Sexual arousal
  • A healthy nervous system
Some causes of ED may require additional or supplementary treatments to Sildenafil. These can include issues with nerve damage or those with underlying psychological reasons. You should work with your GP to find the cause of the issue before taking Sildenafil tablets or any other ED treatment.

Taking Sildenafil for the First Time

The typical initial dose will be a single 50mg Sildenafil tablet. If this is effective then the dose may be reduced to 25mg to see if the same results can be achieved with the smaller dose. If the 50mg has little to no effect, or if the effects last less than 4 hours, the dose may be increased to a single 100mg tablet.

Alternatives to Sildenafil

The main alternative ED treatments include Cialis, Spedra and Levitra, and are available through the Dr.Felix website following a consultation with our GP’s. They also come in various dosages and packet sizes to suit your requirements.

Sildenafil tablets come in three different strengths, 25mg, 50mg and 100mg.

Each tablet contains the active ingredient sildenafil at the indicated strength amount.

How you can take sildenafil is dependent on factors like your age, medical history and other prescription medicine you are on. The common recommended dosage for sildenafil tablets is 50mg consumed anywhere between half hour to four hours prior to sexual intercourse. However, the dosage can be adjusted depending on the individual and how they react to it.

You should not take sildenafil more than once daily, preferably on an empty stomach since it can slow down the effect if taken with a meal. Take sildenafil tablets whole with a full glass of water.

Sildenafil Side Effects

These side effects should be reported to a doctor immediately, and alternative treatment method should be sought in case of the occurrence of these side effects.

Uncommon Side Effects

Less common side effects which have been reported in less than 10% of the consumers include feeling of tenderness in the stomach region, pain or upset stomach, pain during urination, and bladder pain. Also consumers have reported heartburn, feeling of tingling in the body, blood or mucus in the urine, faintness and increased frequency of urination.

Rare Side Effects

These side effects are rarely recorded, with their frequency being reported less than 0.1%. However, just because a side effect is rare doesn’t mean it cannot occur. These side effects include decrease in vision and abnormal eyesight; feeling of being high on alcohol or caffeine; eye bleeds, pain in chest and bone, increase in breast size, and loss in hearing. Feeling of confusion, cold sweats, chills, seizures and paleness of skin has also been reported in rare cases.

Records of pain in the back, pupil dilation, dehydration, severe headaches, fever, heart palpitations, dry eyes and mouth, orthostatic hypotension, and eye irritation have also been mentioned. Skin irritation including peeling, scaling, rash and dryness has also been recorded. Some users have also recorded feeling of extreme hunger and loss of concentration.

Other rare side effects include feeling of weakness, sore throat, slurry speech, and skin problems such as ulcers, hives, itching and lesions. Attention has also been brought to side effects of shakiness, light sensitivity, altered perception of colours, insomnia, prolonged penile erection, swollen and painful joints, nervousness and nightmares. Rare incidence of temporary vision loss, breathing problems, body swelling and muscle twitching has also been recorded.

Side Effects That Do Not Require Medical Attention

These side effects might occur in the beginning at the initial use of sildenafil based medication, but go away with the regular usage of the medicine. While these side effects go away, if they remain consistent, then they need to be brought into medical attention.

Common Side Effects

More than 10% users of sildenafil report initial side effects of red and warm skin, trouble sleeping properly, runny or stuffed nose, feeling of indigestion after eating something, and pain around the cheekbones and eyes. Users have also complained of headaches, flushing, short breathing, diarrhoea, nose bleeds and muscle pain.

Rare Side Effects

Less than 1% people have complained about side effects after initial usage of sildenafil based medicines. These side effects include a feeling of buzzing or ringing in the ears and ear pain; gum soreness, swelling, redness or bleeding; haemorrhoids or rectal pain; tongue irritation and redness and increased amount of saliva production. Other side effects include stomach pain, vivid dreams, unstable balance, difficulty in swallowing, depression, incontinence, vertigo, excessive sleepiness, lip and mouth ulcers, tremors and worsened asthma.

Any medication can cause side effects if the user is not compatible with the medicine uptake. These side effects can be due to individual responses, interaction with other medication, or a result of an interaction with the underlying disease. The best person to guide on the proper dosage and intake of the medication is your doctor, whom you should seek for advice when in doubt.

Refer to the patient information leaflet for a more detailed list of side effects and warnings.