Viagra (sildenafil) tablets to treat erectile dysfunction available in 25mg, 50mg, and 100mg strengths.

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How to buy Viagra online

  1. Read medical information about erectile dysfunction
  2. Answer medical questions to check for eligibility
  3. Reviewed by doctors - posted from UK pharmacy

Low cost generic Viagra

Viagra lost its exclusive patent in the UK in June 2013 and is now available legally in the UK under the name sildenafil. Sildenafil is sometimes also known as generic Viagra or generic sildenafil. ‘Viagra’ is a brand name, ‘sildenafil’ is the medical name.

Generic sildenafil is available at much lower cost, from £1.50 per tablet.


Prices of Viagra/sildenafil tablets
Tablet type4 tablets8 tablets16 tablets32 tablets
Sildenafil 25mg£8.60£14.80£24.80£48.80
Sildenafil 50mg£9.20£16.20£26.80£52.00
Sildenafil 100mg£9.80£17.80£28.40£54.00
Viagra 25mg£24.20£44.30£82.00n/a
Viagra 50mg£29.40£59.50£112.60n/a
Viagra 100mg£33.80£64.45£124.50n/a

Prescription issued online - small prescription fee per order.

Compare prices: Dr Fox prices are 25%-50% lower cost than other online clinics.

Prescription fees

Dr Fox supplies medicine on prescription and charges a small prescription fee based on the order value of each prescription.

Prescriptions are issued by our doctors online and sent electronically to our pharmacy.

If you have your own private paper prescription please post to our pharmacy (details).

Dr Fox prices are 25%–50% lower than other UK online clinics.

Order valuePrescription fee
up to £10£1.00
up to £20£3.00
up to £50£5.00
up to £100£8.00
over £100£10.00
Compare prices of Viagra/sildenafil tablets from UK online clinics (11 July 2017) - qualifying notes
*Dr Fox adds a small prescription fee not included in table above.
  1. The prices shown are listed by the online clinics named after a customer first enters consultation information and is offered prescriptions. It is possible these clinics may have special offers or lower prices for repeat supplies.
  2. Prices may change and are, to the best of our knowledge, accurate on the date stated.
  3. Dr Fox does NOT claim to provide a superior service to any of the online clinics listed. All the clinics listed, as far as we can tell, comply with all regulation and, as far as we can tell, operate to high ethical standards.
  4. Dr Fox adds a small prescription fee not included in the table (between £1 and £10 depending on value of the order).
  5. To amend the information in this table please contact us
  6. The prices listed in the table do not identify the cost of prescription medicine as online clinics charge a single fee to cover services which includes advice, consultations, prescriptions and dispensing and supply of treatments.
Generic/BrandedDr Fox*Express PharmacyHealth ExpressPharmacy 2UMed Express
Generic 25mg x 4£8.60£19.99£24.99£15.00£15.99
Generic 25mg x 8£14.80£29.99£30.00£23.00£29.99
Generic 25mg x 16£24.80£49.99£60.00£40.00£49.99
Generic 25mg x 32£48.00n/a£89.99£60.00£89.99
Generic 50mg x 4£9.20£19.99£26.99£23.00£19.99
Generic 50mg x 8£16.20£29.99£35.00£38.00£29.99
Generic 50mg x 16£26.80£49.99£65.00£60.00£49.99
Generic 50mg x 32£52.00n/a£94.99£86.00£89.99
Generic 100mg x 4£9.80£19.99£34.99£27.00£19.99
Generic 100mg x 8£17.80£29.99£44.99£56.00£29.99
Generic 100mg x 16£28.40£49.99£69.99£75.00£49.99
Generic 100mg x 32£54.00n/a£99.99£130.00£89.99
Viagra 25mg x 4£24.20£44.99£39.99£32.50£29.99
Viagra 25mg x 8£44.30£69.99£69.99£50.00£59.99
Viagra 25mg x 16£82.00£129.99£124.99£95.00£119.99
Viagra 50mg x 4£29.40£44.99£44.99£37.50£34.99
Viagra 50mg x 8£59.50£76.99£74.99£60.00£69.99
Viagra 50mg x 16£112.60£149.99£144.99£114.00£139.99
Viagra 100mg x 4£33.80£46.99£49.99£40.00£34.99
Viagra 100mg x 8£64.45£79.99£79.99£60.00£69.99
Viagra 100mg x 16£124.50£159.99£149.99£95.00£139.99
UK Delivery£2.90£2.95included£3.45£2.90

Delivery charges

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About Viagra

The revolutionary pill

Pfizer logo

Viagra – the little blue pill recognised across the world – has changed the face of erectile dysfunction treatment since its market release by Pfizer in 1998. With its relatively few side effects, ease of use and its effectiveness, it is little wonder the drug has become so popular.

Viagra was under patent protection in the UK until June 2013, after which legal cheaper versions of generic Viagra (sildenafil) have been made available.

What does it do?

The active ingredient in Viagra/sildenafil is sildenafil citrate, which is known medically as a PDE5 inhibitor. Viagra/sildenafil inhibits an enzyme which regulates blood flow in the penis. PDE5 inhibitors multiply the natural process of arousal and increase blood flow to the penis in situations of sexual stimulation. Viagra/sildenafil helps to achieve an erection but relies on natural arousal as a trigger. It, and other PDE5 inhibitors, support sexual relations when erections are failing.

Why do men get erectile dysfunction?

Many factors can contribute to impotence (erectile dysfunction). Lifestyle choices, such as excess drinking, smoking, illegal drug use, as well as obesity and stress, can all have an impact on erections. Erectile dysfunction can also be a symptom of underlying health problems such as atherosclerosis, heart disease, and diabetes, amongst others.

Men suffering from erectile dysfunction should inform their GPs who will undertake an assessment, possibly perform tests, and provide advice.

Why Viagra/sildenafil?

Viagra is a well known and widely used drug. Side effects are normally not troublesome. Onset of action tends to be reliable and predictable. Viagra/sildenafil normally starts to work 30 to 60 minutes after it is taken and usually remains active for in the region of 4 hours.

Other erectile dysfunction drugs, Cialis, Levitra and Spedra, work in a similar way, with similar side effects. Viagra/sildenafil was the first drug in this class to become widely prescribed.

Does it work every time?

As with any treatment, there are times when Viagra/sildenafil might not work and may not improve or overcome the underlying cause of erectile dysfunction. Satisfactory erections require the following:

  • Adequate blood supply
  • Arousal
  • Healthy nervous system

If erectile dysfunction is the result of spinal injury or operation, nerves might be damaged. In this case Viagra/sildenafil may help a little but other measures, such as injections or stiffening aids, may be required.

Other causes of erectile dysfunction may require specialist treatment apart from tablets. Some men, whose erectile dysfunction has psychological causes, may benefit from counselling.

A GP should always be informed.

Alternative treatment

Sildenafil (generic Viagra), Cialis, Levitra and Spedra are alternative oral tablet treatments for erectile dysfunction and are also available to buy online in various strengths and pack sizes after completing the same medical consultation.

Dr Fox also supplies Vitaros cream, a non-tablet treatment for ED.

Taking Viagra/sildenafil for the first time

The usual first starting dose of Viagra is one 50mg tablet. If this strength of tablet is highly effective subsequent doses might be reduced down to one 25mg tablet. If a 50mg tablet is ineffective, or the duration of activity is less than 4 hours, the dose can be increased to one 100mg tablet.

A trial of treatment should be repeated a number of times before deciding whether Viagra/sildenafil is working and before requesting a change of dosage or change to another ED medication. Viagra/sildenafil is most likely to be suitable if taken in situations where arousal is expected within an hour or two of taking the tablet. Arousal is required for the treatment to work. Without it there will be no benefit and the effect of the tablet will simply wear off after about 4 hours.

Viagra dosage

photo of Viagra 25mg pack

Viagra 25mg

Reduced dose recommended when 50mg starting dose is highly effective.

photo of Viagra 50mg pack

Viagra 50mg

Starting dose usually recommended for most men taking Viagra for the first time.

photo of Viagra 100mg pack

Viagra 100mg

High strength dose for when 50mg is insufficient, or erection lasts less than 4 hours.

Recreational misuse

Viagra/sildenafil is sometimes used for recreational rather than therapeutic purposes. If Viagra/sildenafil is taken in this way, particularly in combination with non-prescribed drugs, there is an increased risk of significant side effects, some of which may be serious.

Side effects

Viagra/sildenafil is remarkably well tolerated and free from significant side effects in the vast majority of men who take it.

Slightly over 1% of men taking Viagra/sildenafil notice a bluish or yellowish discolouration of their vision. This is not in itself a cause for concern, and usually does not interfere with normal activity. It wears off after a few hours.

The most commonly reported adverse reactions in clinical studies were headache, flushing, dyspepsia, visual disorders, nasal congestion, dizziness, and visual colour distortion.

In the rare event of serious side effects men should seek immediate medical advice. This applies particularly to chest pains (possibly cardiac), loss of vision, and prolonged and painful erection.

Further detailed information about the side effects of Viagra/sildenafil.

Prolonged painful erections

Priapism is the medical name for prolonged painful erections which have the potential to cause permanent damage to the penis. Priapism is rare. A sustained erection of more than 4 hours requires immediate medical attention.

When not to take

During the assessment process at Dr Fox men are required to complete an erectile dysfunction questionnaire to determine if tablets are suitable.

Men should not take Viagra without further assessment from their GP when the following apply:

  • Low or high blood pressure
  • Allergies or reactions to past ED treatments
  • Recent heart attack (within 6 weeks) or suffer from angina (heart pain on exertion) or any form of heart disease
  • History of strokes or mini-strokes (transient ischaemic attack)
  • History of vision problems caused by circulation problems
  • History in the family of rare degenerative eye disease
  • Serious kidney (renal) or liver disease
  • Peyronie's disease – angulation or deformity of the penis
  • Leukaemia, multiple myeloma or sickle cell disease
  • Bleeding disorders (such as haemophilia)
  • Current active stomach ulcers (peptic ulcer or gastric ulcer)

Dr Fox cannot supply Viagra/sildenafil to men where the above are present.

All men with ED should tell their GPs about it.

Patient information leaflet – Viagra

The 'Patient Information Leaflet' supplied with the medication must be read before taking tablets.

Viagra patient leaflet

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Viagra FAQs

What is Viagra?

Viagra is a brand name medicine for the drug sildenafil and is used to treat men with erectile dysfunction. Viagra works by increasing blood flow to the penis which helps men get and sustain an erection long enough for sex.

Do Viagra tablets become less effective over time?

Not usually, men usually find the same dose will be effective over a period of years. The body does not get used to the treatment. ED tends to be a slowly progressive condition, increasing with age, however unless there is an underlying medical progression the same dose should produce the same effect.

What is the difference between Viagra and sildenafil?

The main difference is the name. Viagra is a brand name for sildenafil. Medically they are the same, having the same active ingredient, the medical name of which is sildenafil. Both come in packs of 4 and 8 tablets and in strengths of 25mg, 50mg, and 100mg. Sildenafil is usually much lower cost because it is produced by numerous competing drug companies. Branded Viagra is produced only by Pfizer.

What is the difference between Viagra, Cialis, and Levitra?

The main difference is their duration of action: Viagra works for about 4 hours; Levitra for about 12 hours; and Cialis for about 36 hours. Each of these medicines work in the same way, by changing the blood flow in the penis. Some men find one works better for them than another, although most men find each one equally effective, but for different durations. Men can choose which tablet they use depending on the time they expect to be sexually active. An erection will only occur in the presence of arousal, and without it the treatment remains inactive.

Can I get Viagra on the NHS?

NHS GPs can prescribe Viagra, although usually do so in limited quantities (1 per week) and mostly the generic version sildenafil. NHS prescription fees apply. See Sildenafil on the NHS.

Can my regular doctor give me a private prescription for Viagra?

Most doctors will be able to prescribe Viagra privately, although they will make a charge for this, usually around £25.00 per prescription. Online services are nearly always lower cost.

Can I split Viagra tablets?

Viagra tablets are scored and can be broken in two. This may be a more cost effective way of using the treatment as the cost of the tablets is not proportional to the amount of active ingredient. A 100mg tablet does not usually cost twice as much as a 50mg tablet. If you find a 50mg tablet is effective, then half a 100mg will be just as good, as will two 25mg tablets. It is the overall amount of active ingredient which matters. 25mg tablets (the lowest dose available) should not be cut in half.

What is the usual recommended starting dose of Viagra?

Most men start on a dose of one 50mg tablet, although men over the age of 65 years would normally start on the lowest dose tablet of 25mg. It is a good idea to try the same dose at least 4 times before deciding to increase the strength of tablet. The maximum dose of a single treatment is 100mg and this should not be repeated within 24 hours.

Can ED tablet treatments be combined, e.g. Viagra with Cialis?

No. The commonly used ED treatments (Cialis, Viagra, and Levitra) work in the same way. Using more than one at the same time will not make treatment more effective, and risks overdose and unwanted side effects. Leave a gap between using one type of treatment and another of at least 24 hours (36 hours for Cialis).

Can I drink alcohol with Viagra?

It is recommended not to drink alcohol or only a minimal amount of no more than one or two units. Alcohol increases symptoms of erectile dysfunction. There is no direct chemical interaction between Viagra and alcohol, however the risk of side effects such as a drop in blood pressure and even fainting will increase when Viagra is used after heavy drinking. The treatment may also be ineffective.

Should men with ED consult their regular doctors before taking Viagra?

ED can be a sign of an underlying medical condition, such as reduced circulation, diabetes, high cholesterol, or a neurological or hormonal issue. These things need to be assessed by a doctor face-to-face and men taking Viagra should have check-up periodically. It is fine to obtain Viagra online, however proper diagnosis and review are required.

Can stress cause ED?

Yes, particularly stress in a relationship or around sexual activity can cause ED. Erections are usually stronger in men who are relaxed, rested, and comfortable with their partners. Counselling can be effective for some men who are have ED, particularly younger men who have no underlying physical cause of their ED.

What are the risk of taking Viagra with recreation or illegal drugs?

Men taking Viagra and drugs at the same time are open to numerous risks, from impulsive unsafe behaviour, excessive dosing, and increased side effects, to the serious and potentially irreversible damage caused by the rare condition of priapism. In priapism there is a continuous prolonged erection of more than an hour or two, which can damage the erectile tissues. There is an increased risk of priapism when Viagra is taken with cocaine. See Beware club drugs and Viagra.

Why does the cost of Viagra vary so much?

Pharmacies, when providing medicines on private prescriptions, are free to charge what they choose. Some pharmacies will charge higher prices and make bigger profits, others may choose lower prices in the expectation that men will return when buying repeat supplies.

The Dr Fox website sells Viagra (sildenafil) online at a lower cost than other UK regulated pharmacies on the internet (see price comparison table above).

Is Viagra a prescription only medicine?

Yes, Viagra is obtained legally in the UK only if a doctor writes a prescription for it and a registered pharmacy dispenses it. When Viagra is ordered online an electronic prescription is involved. The only exception applies where a specialist pharmacist supplies Viagra on a pharmacist written prescription or using a 'patient group direction'. An application is currently being considered by the medicines regulator to permit the purchase of sildenafil over the counter. In all cases only registered pharmacies are permitted to supply it.

Are Viagra, Cialis, and Levitra as strong as each other?

Yes, generally men will respond equally well to the equivalent dose of these tablets. The lower strength of each is: Viagra 25mg, Cialis 10mg, and Levitra 5mg; and the upper doses 100mg, 20mg, and 20mg respectively. Some men might find they feel a stronger response to one type of treatment rather than another although this is generally not the case. There is also an alternative daily dose of Cialis 2.5mg and 5mg tablets for men who require continuous treatment.

How long does it take for Viagra to work?

Usually around 30 to 45 minutes when tablets are taken on an empty stomach, and up to 60 to 90 minutes if taken within 30 minutes after a meal. Fatty meals will delay absorption of Viagra longer than non-fatty ones.

When should I take Viagra?

Viagra should normally be taken at least an hour before sexual activity, but preferably no longer than three hours before. Viagra tablets remain active for about 4 to 5 hours after taking a tablet, although this can vary from one time to the next and from one person to another.

Can Viagra go out of date?

The shelf life of Viagra is 5 years. This means it will stay in-date for 5 years after the manufacture date written on the packet. It should be stored at below 30°C, which means keeping tablets out of direct sunlight. Packets will be printed with expiry dates and you should always read the information leaflet enclosed in packs.

See also erectile dysfunction FAQs page.

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Authored 7 December 2012 by Dr Tony Steele, MB ChB

Reviewed 30 July 2017 by Dr B. Babor, Dr A. Wood, Dr P. Hunt

Last updated 8 August 2017

Product reviews

Viagra rated 8.91/10 in 108 product reviews

See over 8,800 service reviews of Dr Fox

Good, prfeesional

30/07/2017 06:01
Anonymous Verified

No side effects at all.

28/07/2017 19:16
Anonymous Verified

100% hits the target and maintains for a good few hours

26/07/2017 08:14
Anonymous Verified

super, a little help when you need it

26/07/2017 07:01
Anonymous Verified

very good works very well

25/07/2017 11:20
Anonymous Verified

tried this yesterday and very pleased that I was able to achieve an erection and maintain this.First in a while)))))

20/07/2017 16:10
Anonymous Verified

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