Sildenafil tablets, used to treat erectile dysfunction and pulmonary arterial hypertension, come in various colours depending on the manufacturer and formulation. Whilst the branded Viagra® is famously blue, generic sildenafil—widely available in the UK since patent expiry—appears in white, off-white, yellow, and other hues. Understanding what colour your sildenafil should be aids medication identification, reduces the risk of errors, and helps detect counterfeit products. The Medicines and Healthcare products Regulatory Agency (MHRA) regularly warns about fake sildenafil sold online. Always obtain sildenafil through legitimate channels: your GP, a registered pharmacy, or a regulated online pharmacy displaying the General Pharmaceutical Council (GPhC) logo.

What Colour Is Sildenafil and Why Does It Matter?

Sildenafil, the active pharmaceutical ingredient used to treat erectile dysfunction and pulmonary arterial hypertension, comes in various colours depending on the manufacturer, formulation, and dosage strength. In the UK, the most commonly recognised sildenafil tablets are blue, particularly the branded Viagra® tablets manufactured by Pfizer. However, generic versions of sildenafil—which have been widely available since the patent expired—come in a range of colours including white, off-white, yellow, and others.

It's worth noting that sildenafil for pulmonary arterial hypertension (marketed as Revatio®) typically comes as white 20mg tablets, distinct from the erectile dysfunction formulations.

Understanding the colour of your sildenafil tablets matters for several important reasons. Firstly, it helps with medication identification and safety. Being able to recognise your prescribed medication reduces the risk of taking the wrong tablet, especially if you are managing multiple medications. Secondly, colour can be a useful indicator when checking for counterfeit or substandard medicines. The online market for erectile dysfunction treatments has unfortunately led to a proliferation of fake medications, some of which may contain incorrect doses, harmful substances, or no active ingredient at all.

The Medicines and Healthcare products Regulatory Agency (MHRA) regularly issues warnings about counterfeit sildenafil products. Knowing what your legitimate medication should look like—including its colour, shape, and markings—provides an additional layer of protection. It is worth noting that whilst colour can aid identification, it should never be the sole method of verifying authenticity. Always obtain sildenafil through legitimate channels: your GP, a registered pharmacy, or a regulated online pharmacy displaying the General Pharmaceutical Council (GPhC) logo. In the UK, Viagra Connect® (50mg) is available from pharmacies without a prescription following an assessment by a pharmacist, while other sildenafil products require a prescription.

Different Colours of Sildenafil Tablets in the UK

The colour variation in sildenafil tablets available in the UK reflects the diversity of manufacturers producing both branded and generic versions. Viagra®, the original branded product, is characterised by its distinctive blue, diamond-shaped tablets. This iconic appearance has become synonymous with sildenafil in popular culture, leading to the colloquial term "the little blue pill." Viagra is available in 25mg, 50mg, and 100mg strengths, all maintaining the blue colour with different markings to denote dosage.

Generic sildenafil tablets, which are bioequivalent to Viagra but typically more affordable, come in a wider array of colours. Common presentations in the UK include:

• White or off-white tablets: Perhaps the most prevalent colour for generic sildenafil, produced by numerous manufacturers including Teva, Accord, and Viatris (formerly Mylan)

• Yellow tablets: Offered by some generic manufacturers, these may be round or oval in shape

• Film-coated variations: Some manufacturers use coloured coatings which may appear blue, white, or other hues

Sildenafil for pulmonary arterial hypertension (Revatio®) is typically supplied as white 20mg tablets, distinguishing it from erectile dysfunction formulations.

The specific colour often depends on the inactive ingredients (excipients) used in the formulation, such as colourants, binders, and coating agents. Different manufacturers select excipients based on their formulation preferences and to create product differentiation in the marketplace, while regulatory authorities ensure these ingredients meet safety and quality standards. It is important to note that the colour of the tablet has no bearing on the efficacy of the active ingredient—a white generic sildenafil tablet contains the same active pharmaceutical ingredient as a blue Viagra tablet of equivalent strength, provided both are genuine, licensed medicines.

How to Identify Genuine Sildenafil by Appearance

Identifying genuine sildenafil requires attention to multiple physical characteristics beyond colour alone. When you receive sildenafil from a legitimate source, examine the following features carefully:

Tablet markings and imprints: Authentic sildenafil tablets bear specific markings that identify the manufacturer and dosage. Viagra tablets, for example, are imprinted with "Pfizer" on one side and "VGR" followed by the strength (25, 50, or 100) on the reverse. Generic versions will have different markings specific to their manufacturer—these should be clearly visible and precisely stamped, not blurred or uneven.

Packaging integrity: Genuine sildenafil comes in professional pharmaceutical packaging with clear labelling, including the product name, strength, batch number, expiry date, and manufacturer details. The packaging should display the appropriate regulatory markings, including the Product Licence (PL) number, and contain a patient information leaflet. Be suspicious of packaging with spelling errors, poor print quality, or missing information.

Tablet consistency: Legitimate tablets should be uniform in size, shape, and colour within the same batch. Variations in appearance between tablets from the same packet may indicate counterfeit products. The tablets should be smooth and evenly coated if they have a film coating.

Source verification: Perhaps most importantly, only obtain sildenafil from registered pharmacies. In the UK, legitimate online pharmacies must display the GPhC internet pharmacy logo, which you can verify on the GPhC website. The distance-selling logo should link directly to the pharmacy's entry on the GPhC register. Be wary of websites that offer prescription-only sildenafil without requiring a prescription or appropriate clinical assessment. Remember that while Viagra Connect (50mg) can be supplied by pharmacists without a prescription following an assessment, other sildenafil products require a prescription.

If you have any concerns about the authenticity of your medication, do not take it. Contact your pharmacist or GP immediately, and report suspected counterfeit or defective medicines to the MHRA through their Yellow Card scheme or directly to the MHRA Enforcement team.

Does the Colour of Sildenafil Affect How It Works?

The colour of sildenafil tablets has no impact whatsoever on the medication's therapeutic efficacy or mechanism of action. Sildenafil works by inhibiting phosphodiesterase type 5 (PDE5), an enzyme that regulates blood flow in the penis. By blocking PDE5, sildenafil enhances the effects of nitric oxide, allowing smooth muscle relaxation and increased blood flow to facilitate an erection in response to sexual stimulation. This pharmacological action is determined entirely by the active ingredient—sildenafil citrate—not by the colour or appearance of the tablet.

The colourants used in pharmaceutical tablets are inactive ingredients that serve aesthetic and identification purposes only. These excipients must meet stringent safety standards set by the MHRA and European Medicines Agency (EMA), ensuring they should not materially affect drug absorption, distribution, metabolism, or excretion. Common pharmaceutical colourants include titanium dioxide (white), iron oxides (yellow, red, or black), and various approved dyes. If you have allergies or intolerances, check the Patient Information Leaflet (PIL) for a full list of excipients.

What does matter for efficacy is the bioavailability and pharmaceutical equivalence of the product. Generic sildenafil must demonstrate bioequivalence to the branded version, meaning it delivers the active ingredient into the bloodstream within accepted ranges (typically 80-125% for key parameters) compared to the reference product. This is rigorously tested during the regulatory approval process. Whether your sildenafil is blue, white, or yellow, if it is a licensed medicine obtained from a legitimate source, it will provide the same therapeutic benefit.

Patients sometimes report perceived differences between branded and generic medications, but clinical evidence consistently shows no significant difference in efficacy when products are genuinely bioequivalent. If you experience different effects after switching between brands or generics, discuss this with your GP or pharmacist—it may relate to other factors such as timing of administration, food intake, or psychological expectations rather than the colour of the tablet itself.

Important safety information: Sildenafil is contraindicated in patients taking nitrates or nitric oxide donors (such as GTN spray or isosorbide mononitrate) and riociguat, as this combination can cause dangerous drops in blood pressure. Use with caution if you take alpha-blockers. Seek urgent medical attention if you experience chest pain, an erection lasting more than 4 hours (priapism), or sudden vision or hearing loss. Report any suspected side effects via the MHRA Yellow Card scheme.

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