Sildenafil Tablets: What They Are For and What They Look Like

• Sildenafil tablets are licensed in the UK for erectile dysfunction in men aged 18 and over
• There is no single sildenafil tablet appearance, because inactive ingredients including colourings differ between manufacturers
• Appearance cannot confirm a tablet's identity, strength or authenticity, which is exactly what makes it the wrong check to rely on
• MHRA seized more than 15.5 million doses of illegally traded medicines in 2023 and named erectile dysfunction products among the categories involved

Sildenafil tablets treat erectile dysfunction. They are a prescription medicine in the UK, licensed for men aged 18 and over, and taken only when needed.

The appearance question has a different kind of answer, and it is worth giving straight away. There is no single thing sildenafil looks like. Sildenafil is made by many authorised manufacturers, and while every product must contain the same active substance at the same strength, the inactive ingredients that determine colour, shape and markings are not standardised. One company's sildenafil 50mg can be white and round while another's is blue and oval.

That is not a gap in the information. It is the answer, and it carries a consequence most pages do not spell out: if appearance varies legitimately, appearance cannot be used to verify that a tablet is genuine. Anyone checking authenticity by looking at the tablet is using the one method a counterfeiter can copy most easily.

This page covers what sildenafil tablets are for, including treatment of erectile dysfunction and pulmonary arterial hypertension, why they look different from one another, what the markings and shapes actually mean, and the checks that do work. Results vary between individuals.

Sildenafil works by producing smooth muscle relaxation through inhibition of the phosphodiesterase type-5 enzyme, enhancing blood flow in the penile tissue during stimulation. It is important to note that sildenafil treatment requires appropriate stimulation to be effective and does not cause spontaneous erections.

Patients with severely impaired hepatic function or severe renal impairment should use sildenafil cautiously, as these conditions affect sildenafil clearance and may require dosage adjustment. Similarly, those with severely impaired autonomic control or cardiac risk factors such as coronary artery disease or left ventricular outflow obstruction should be assessed thoroughly before starting treatment.

Clinical trials and controlled clinical trials have demonstrated sildenafil’s efficacy and safety profile, but adverse reactions such as blurred vision, prolonged erection, or allergic reaction can occur. Patients should be advised about potential drug interactions, including concomitant administration with alpha blocker therapy prior to sildenafil use, and the effects of grapefruit juice which can increase plasma levels of the drug.

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Key things to know

• Sildenafil is licensed in the UK as 25mg, 50mg and 100mg film-coated tablets for erectile dysfunction.
• MHRA documentation describes one specific product as blue, rounded and diamond-shaped, supplied in blisters of 2, 4 or 8.
• Generic products differ in colour, shape, size and markings because their inactive ingredients differ.
• A white sildenafil tablet is not evidence of anything wrong, and neither is a blue one.
• The leaflet inside your own pack is the authority on what your tablets should look like.
• MHRA lists crumbly tablets, damaged packaging, a missing leaflet and a missing expiry date among the signs of a fake.
• A site selling prescription medicines with no prescription required is not operating lawfully.
• If you suspect a medicine is fake, MHRA advice is not to take it.
• Suspected side effects and suspect products can be reported through the MHRA Yellow Card scheme.

What are sildenafil tablets used for?

Sildenafil tablets are used to treat erectile dysfunction in men aged 18 and over. That is the licensed use of the tablets this page describes.

Erectile dysfunction means being unable to get or keep an erection firm enough for satisfactory function. Sildenafil belongs to a group of medicines called PDE5 inhibitors, which increase blood flow to the penis by keeping a natural signalling molecule active for longer during stimulation.It treats erectile dysfunction symptoms for a limited period rather than addressing the underlying cause. Erectile dysfunction can have psychological or physical causes and may warrant medical assessment.

The question gets typed in several different ways. Sildenafil tablets, what are they for, what are sildenafil tablets for and sildenafil tablets for are all the same question, and the answer above is the whole of it.

Sildenafil is also formulated under separate licences at different doses for conditions unrelated to erectile dysfunction, including pulmonary arterial hypertension. Those are different products with different authorisations, and nothing on this page applies to them.

Sildenafil tablets uses and dosage

Sildenafil tablets uses and dosage are set by the licence and by your prescriber, not by anything on this page.

MHRA documentation records the dose as one tablet taken as needed, approximately 1 hour beforehand, with a maximum of one tablet in any 24 hour period. It is usually taken approximately 1 hour before sexual activity. Food can delay the onset of activity, particularly after a high-fat meal.

Treatment suitability depends on an individual clinical assessment, and your prescriber will determine the appropriate treatment. Never take more than one tablet in 24 hours, and never take two tablets of a lower strength to make a higher one.

Sildenafil must never be taken with nitrates, nitric oxide donors or riociguat. This medicine should only be used under the supervision of an appropriately qualified prescriber.

What does sildenafil look like?

Sildenafil tablets are film-coated tablets, meaning a compressed core with a thin outer coating, but their colour, shape, size, and markings vary between manufacturers.

MHRA documentation describes one specific sildenafil product as a "film-coated tablet" and, more precisely, as "blue, rounded diamond-shaped tablets," supplied in PVC and aluminium foil blisters in cartons of 2, 4, or 8 tablets.

That description is accurate for that product and does not describe sildenafil generally. Anyone asking what sildenafil pills look like and expecting one answer is asking a question the market does not have a single answer to.

Sildenafil tablets contain the same active ingredient regardless of appearance. This active substance works by enhancing blood flow through oral administration, typically as a single oral dose taken within the recommended dose range. It is important to advise patients that sildenafil enhances the natural process of blood vessel relaxation in the isolated human corpus cavernosum during stimulation, without causing an effect on its own.

The usual recommended dose for erectile dysfunction is 50mg, although the dose may be adjusted to 25mg or 100mg depending on efficacy and tolerability and on individual clinical factors. Plasma protein binding influences sildenafil's distribution in the body, and fixed dose studies have helped establish safe dosing guidelines.

Sildenafil should be used cautiously in patients with aortic stenosis or other cardiovascular conditions. Oral therapy with sildenafil is contraindicated in patients taking nitrates due to the risk of symptomatic hypotension.

Why sildenafil tablet appearance varies

Sildenafil tablet appearance varies because the law standardises the active substance and not the inactive ones.

A UK generic must contain the same active substance as the reference medicinal product, in the same pharmaceutical form, and must be shown to be bioequivalent to it. What it does not have to match is the appearance. Colourings, coating agents, fillers and binders are chosen by each manufacturer.

The excipient list MHRA publishes for one product illustrates the point. Its core contains microcrystalline cellulose, calcium hydrogen phosphate, croscarmellose sodium and magnesium stearate, and its film coat contains hypromellose, titanium dioxide, lactose, triacetin and indigo carmine aluminium lake. Change any of those and the tablet in front of you changes with it, while the medicine does not.

Sildenafil blue pill: where the blue comes from

In the specific product described by the MHRA, the blue colour comes from a colouring agent in the film coat rather than from sildenafil itself.

In the product MHRA documents, the colouring is indigo carmine aluminium lake, listed as E132. It sits in the outer coat alongside hypromellose and titanium dioxide. It has no therapeutic role at all.

The association between sildenafil and a blue tablet comes from the original branded product being blue, and it has stuck culturally far more firmly than it holds in practice. Sildenafil blue pill describes one appearance, not the medicine.

Sildenafil white tablet and other colours

A white sildenafil tablet is a normal and expected thing to receive, and it is not a sign that anything is wrong.

Because colourings are not standardised, a manufacturer that does not add one produces a white or off-white tablet. Others produce blue, and some produce other colours entirely. Licensed sildenafil products at the same stated strength contain the same active substance, although their inactive ingredients, appearance and formulation details may differ.

This matters because a great many people receive a white tablet, remember the cultural blue, and conclude they have been given the wrong thing or something counterfeit. In most cases they have simply been supplied by a different manufacturer's product. The way to settle it is the leaflet in the pack, not the memory of an advert.

Sildenafil 50mg tablet colour and the 100mg tablet

Sildenafil 50mg tablet colour is set by the manufacturer, not by the strength, and the same is true at every strength.

Ask sildenafil 100mg what does it look like and the honest answer is identical in structure: it depends entirely on who made it. Some manufacturers use the same colour across their whole range and distinguish the strengths by size or by the marking pressed into the tablet. Others vary the colour by strength. Neither approach is standard.

Do not use colour to work out a strength. If you are unsure which strength you are holding, the dispensing label and the leaflet tell you, and the pharmacy that supplied it can confirm it.

Sildenafil tablet shape and markings

Sildenafil tablet shape and sildenafil tablet markings are chosen by the manufacturer to identify their own product, and they are not a national code.

Tablets are commonly round, oval, oblong or diamond-shaped. Markings may be letters, numbers, a score line, a logo, or nothing at all.A score line may indicate that a tablet can be divided, but whether a particular tablet can be split should be confirmed from its product information or by asking a pharmacist.

What matters is that these are manufacturer-specific. Two boxes of sildenafil 50mg from two different authorised companies can carry entirely different markings, and both are genuine.

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Sildenafil pill identifier: why appearance cannot identify a tablet

A sildenafil pill identifier based on colour, shape and imprint cannot reliably tell you what a loose tablet is, and relying on one carries real risk.

There are three reasons, and each is enough on its own.

1. Appearance is not unique. Many different medicines share a colour, a shape and a size. A visual match is a guess, not an identification.
2. Appearance changes. Manufacturers reformulate, packaging changes, and a product that looked one way last year may look different now.
3. Appearance is the easiest thing to copy. A falsified product is manufactured specifically to look like a genuine one, so the closer a fake is to convincing, the less appearance tells you.

Tablet markings are generally manufacturer- or product-specific identifiers. They should be checked against the packaging and product information rather than used alone to establish the identity or authenticity of a loose tablet.

What actually identifies your medicine

• The dispensing label on the pack, which names the medicine, the strength and who it was supplied to
• The patient information leaflet inside the pack, which describes what that specific product looks like
• The outer carton, which carries the product name, strength, batch number and expiry date
• The pharmacy that supplied it, which can confirm what it dispensed against your record

If a tablet is loose, unlabelled and you do not know where it came from, none of those exist for it. The safe answer in that situation is not to take it.

Sildenafil vs Viagra pill appearance

Sildenafil vs Viagra pill appearance is a comparison between one branded product with a fixed appearance and a whole category of generic products with many appearances.

Viagra is a brand name for sildenafil. Both contain the same active substance, and a UK generic must be bioequivalent to the reference product. The branded tablet has one consistent look because it comes from one manufacturer. Generic sildenafil has many, because it comes from many.

The practical point is that a generic tablet looking nothing like the branded one is expected rather than suspicious. Appearance is the difference you are allowed to see. There is not a difference in what the medicine does.

How to tell if sildenafil is genuine

You tell whether sildenafil is genuine by checking where it came from, not by looking at the tablet.

The single most reliable check is the supply route. Obtaining sildenafil from a registered UK pharmacy through the appropriate prescribing or pharmacy process provides an important safeguard, although consumers should still check the packaging and product information. . Medicine bought from an unverified seller does not, whatever it looks like.

MHRA guidance is blunt about the alternative: "Buying medicines from unverified sources, online or elsewhere, means there is no guarantee that the products are safe or effective."

Fake sildenafil: how to spot the warning signs

Searches for fake sildenafil to spot usually come after a purchase rather than before one. MHRA publishes warning signs for both the product and the seller.

Warning signs on the medicine itself

MHRA lists these as indicators of a falsified medicine:

• Poor quality capsules or crumbly tablets
• Medicines with a homemade appearance, or packaging that is open or damaged
• Packaging missing the "UK Only" label
• Active ingredients not listed on the packet
• A missing patient information leaflet
• A missing or past expiry date

Read that list next to everything above and a pattern emerges. None of these signs is the colour or shape of the tablet. They are about quality, completeness and documentation, which is what falsification actually degrades.

Warning signs on the seller

MHRA also publishes signs that a website is not operating legitimately:

• An unusual web address, since legitimate retailers will not use a product name in the URL
• Poor website design with spelling or grammatical errors
• Pop-up advertisements
• Exaggerated claims such as "100% safe", "no side effects" or "quick results"
• Promises of quick next day delivery
• Advertising prescription only medicines and prices on the home page, which is illegal in the UK
• No prescription required for prescription medicines
• Payment accepted in cryptocurrencies
• Being asked not to name the medicine or website in your banking transaction reference
• No physical or street address available

The clearest of these is the seventh. A prescription-only sildenafil product cannot lawfully be supplied without the prescription or other authorised pharmacy process required for that product. A site that offers to skip that step has told you what it is.

How large is the problem?

Large enough that MHRA runs continuous enforcement against it, and erectile dysfunction medicines are named among the categories involved.

MHRA described the 2023 seizures as including "falsified and unlicensed lifestyle products such as erectile dysfunction and hair loss medications". That is the regulator naming this exact category, which is why the verification advice on this page is worth acting on rather than skimming.

What to do if you think you have a fake

Do not take it. That is MHRA's direct advice: "If you suspect you have bought a fake medicine, do not take it."

4. Stop taking it and keep the packaging, including any leaflet, batch number and expiry date
5. If you have already taken it and feel unwell, seek medical help right away
6. Report it through the MHRA Yellow Card scheme, which accepts reports about suspected fake or defective medicines as well as side effects
7. Report the seller through the MHRA service for reporting suspicious online sellers of medicines
8. Speak to a pharmacist or prescriber about getting a properly supplied replacement

Reporting matters more than it feels like it does. Enforcement action against illegal sellers is built on reports, and the figures in the table above are what that process produces.

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Buying sildenafil safely in the UK

Sildenafil is a prescription only medicine in the UK, with one narrow exception: a single 50mg product reclassified by the MHRA in November 2017 is sold from pharmacies after a pharmacist consultation. Everything else requires a prescription.

A legitimate online route looks like this:

1. You complete an appropriate clinical assessment covering relevant medical history and current medicines, with any additional checks required by the prescriber.
2. An appropriately qualified prescriber assesses whether treatment is appropriate and determines the appropriate strength and quantity.
3. If approved, the pharmacy dispenses and dispatches the medicine, with a leaflet and a dispensing label.

When to seek urgent help

• An erection lasting longer than 4 hours needs immediate medical attention
• Sudden loss of vision in one or both eyes, or sudden loss or reduction of hearing, means stopping the medicine and being seen urgently
• Chest pain during or after use is an emergency, and you must say that you have taken sildenafil, because nitrates must not be given
• Fainting or collapse needs assessment
• Feeling unwell after taking a medicine you suspect is not genuine needs medical help right away

Medical Disclaimer

This article is for general information only and is not medical advice. It does not replace an assessment by a qualified healthcare professional. Treatment suitability depends on an individual clinical assessment. Your prescriber will determine the appropriate treatment. This medicine should only be used under the supervision of an appropriately qualified prescriber. Results vary between individuals.

Nothing here instructs you to take a particular strength, quantity or frequency, or to change an existing regimen, and there is no dose escalation plan on this page. The guidance here does not replace the instructions on your dispensing label or in the patient information leaflet supplied with your pack, and where they differ you should follow your prescriber and your leaflet.

This page must not be used to identify a tablet. Nothing here is a pill identifier, and no description on this page should be treated as confirming what any tablet is, what strength it is, or whether it is genuine. Tablet appearance, colour, shape and markings are chosen by each manufacturer and are not standardised, so a match in appearance proves nothing and a mismatch proves nothing. The blue diamond-shaped description and the excipient list relate to one specific product documented by the MHRA and are not generalisable. The authority on what your medicine should look like is the patient information leaflet inside your own pack, and the pharmacy that supplied it. If a tablet is loose, unlabelled or of unknown origin, do not take it and speak to a pharmacist.

Dosing, timing and safety information is taken from MHRA documentation relating to sildenafil for erectile dysfunction and does not apply to sildenafil products licensed for other conditions. Seizure figures and warning signs are as published by the MHRA for the periods stated. The warning signs listed are indicators rather than a complete test, and the absence of them does not confirm that a product is genuine.

Do not start, stop or change the strength or frequency of any prescribed medicine because of this page. Never take more than one tablet in any 24 hour period, and never take two tablets of a lower strength to make a higher one. Never combine sildenafil with a nitrate, a nitric oxide donor or riociguat. Suspected side effects and suspected fake or defective medicines can be reported through the MHRA Yellow Card scheme. Seek immediate medical help for an erection lasting longer than 4 hours, chest pain, fainting, or sudden loss of vision or hearing.