What are the differences between Viagra and its generic version: Sildenafil?

  1. Name
  2. Appearance and form
  3. Manufacturer
  4. Price
  5. Efficacy and side effects
  6. How to purchase

In some respects, such as name, appearance and cost, there are some differences; but in others, such as medicinal content and activity of function, there are virtually none.

Since becoming available in 1998, Viagra has become one of the fastest-selling drugs in history, with makers Pfizer reporting that over 23 million men worldwide have used the drug.

The 15-year patent on Viagra ran out in 2013, and at this time the drug became available for generic reproduction.

Because there have been so many counterfeit versions of the drug sold over the internet over the past two decades, the term ‘Generic Viagra’ has become one generally met with scepticism.

But since 2013, Sildenafil has been a legitimate and legal treatment option for ED.

So what’s the difference? To clear up any confusion, we thought we would provide a brief guide to the main differences between the branded version of the drug, Viagra, and its generic counterpart.

Name: Viagra vs Sildenafil

When a pharmaceutical manufacturer first develops a drug they will, like makers of other types of products or consumables, issue it under a marketing-friendly brand name.

In the case of Pfizer, when they released sildenafil for the treatment of ED, the name they gave to their new medicine was Viagra.

When the patent license on a drug runs out, usually after a period of 15-20 years, the Medicine and Healthcare products Regulatory Agency (or MHRA) will grant other companies permission to produce the same medication.

These companies will not, however, be able to sell it under the original branded name. Instead, they will sell it under the name of the active ingredient of the drug: in this case, Sildenafil.

This is why there are often two or more versions of the same product available on the market, which contain the same functioning substances, but are referred to by different names.

You can find out more on our pages for Viagra and Sildenafil

Appearance and Form

In addition to retaining the Viagra name, Pfizer also retained the trademark on the appearance of the drug; the blue diamond shape.

Subsequently, manufacturers of Sildenafil are unable to produce the drug with a similar appearance.

Usually, Sildenafil will be issued simply as a regular-shaped blue or white tablet; however in 2012, Nipatra, a chewable version of sildenafil was released by Mercury Pharma.

Whereas Viagra tablets have ‘VGR’ and the dosage amount inscribed on them, Sildenafil will normally have ‘SL’, followed by the dosage.



The makers of Viagra, unless they decide to sell the brand or are acquired by a rival firm, will always be Pfizer.

Sildenafil on the other hand, is open to wider reproduction, and can be made any pharmaceutical company; provided that they adhere to the same preparation and manufacturing conditions observed to make the original.

It should be noted that Pfizer have also entered the generic market for Sildenafil, and produce their own version.


Sildenafil, as a generic medication, is cheaper than its branded counterpart.

Here at Treated.com, prices for the generic start at £9.99, whereas those for Viagra start at £29.

Essentially, when buying Viagra the patient is paying for the brand, and the product which has been sold to millions.

As the sole makers of Viagra, Pfizer can charge a higher price for the drug. But Sildenafil, which performs the job and is subject to the same production practices, is made by several competing companies, resulting in lower pricing.

Efficacy, Side Effects and Contraindications

The results of the products are clinically the same.

As previously mentioned, Viagra and Sildenafil have the same active ingredient, and perform the same function in the body. This means that they have the same rate of efficacy, carry the same risks of side effects, and are subject to the same contraindicatory restrictions.

Despite the fact that Sildenafil is available, there is a reason that Viagra continues to sell so well; because it is the most established and recognisable prescription medication available for impotence, and will perhaps remain to be for some time.

How You Can Get It

Neither of these medications are available over-the-counter. A doctor will always need to check your suitability for the drug before issuing it to you. More info here.

Viagra can be bought in person or online privately, with a prescription. Some patients may, however, be able to get Sildenafil treatment on the NHS.

Page last reviewed:  12/12/2019