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Sildenafil vs Viagra: Is there a difference?

Medically approved by
Dr Earim Chaudry
Last updated
29th September 2021

In 30 seconds

Sildenafil is the active ingredient in Viagra and in generic, unbranded Sildenafil tablets. Both generic Sildenafil tablets and Viagra work exactly the same, are equally effective, and work for the same duration. The main difference between them is simply the price and branding; Viagra being more expensive.

Sildenafil and Viagra: The Basic Information

When researching your options for erectile dysfunction medications, the huge variety of brands on the market can be a pain to navigate. Finding the right medication shouldn’t be a big deal – millions of men suffer with ED, and you’re simply looking for the best option. We understand the struggle. 

While there are other branded and generic types of ED medications available, such as Tadalafil, Cialis, Levitra, Avanafil and Spedra – Viagra is still the most famous. This is thanks to Viagra being the first solution widely available for assisting men with ED – not to mention its clever marketing over the years. As a result of becoming a household name, Viagra is expected to keep a 29% market share by 2022

On the flip-side is little-known Sildenafil. The less-catchy name might give you reason to pause, but hear us out. Like Viagra, Sildenafil has a high rate of success – whatever the underlying reasons behind your ED. In this article, we’ll try to give you the key info you need to choose between Viagra and Sildenafil.

What Are the Similarities Between Viagra and Sildenafil?

Plainly speaking, Sildenafil and Viagra contain the same active ingredient. Sildenafil is the generic or unbranded version, and Viagra is the globally famous “little blue pill” brand. Though it may seem like Sildenafil is the newbie ED medication on the block, there are no big reasons to prefer the more established Viagra product over generic Sildenafil.

Sildenafil was invented back in the late 1980s by scientists working for American pharmaceutical company, Pfizer. The medication was initially developed to treat heart problems like angina, but was patented by Pfizer in 1998 as Viagra once they’d realised its potential as a licensed ED medication.

Pfizer’s patent for Viagra expired in 2012 for countries outside the US, and it expires completely in 2020. This means that generic forms of the medication, known simply as Sildenafil, can enter the market. 

Both drugs have the same amount of active ingredient (Sildenafil Citrate) in each comparable dose. In medical terms, this is known as bioequivalence. Importantly for you, this means the way both drugs work, how long they take to work, how well they work and how long they work for, are the same. 

So, is Sildenafil as good as Viagra? Yep, that’s right! Despite its notoriety, Viagra is not “better” than Sildenafil or another branded product. They have the same effect on your ability to maintain an erection. 

Important note: The bioequivalence also means you need to steer clear of both Sildenafil and Viagra if you have been medically advised against taking either of them.

Sildenafil and Viagra both work by inhibiting the PDE5 enzyme, which controls muscle contraction in the penis. The drug allows the blood vessels in the penis to relax and expand, boosting the blood flow to the area and making it easier to maintain a lasting erection. It is beneficial to be sexually aroused for both medications to work effectively, so you’ll need to get in the mood, relax, and let the pill do its thing!

Side-effects: Sildenafil vs Viagra

It’s also worth considering that the side-effects of both medications are the same, so if you suffer from unwanted symptoms after taking Viagra, the same is likely to occur with a generic Sildenafil medication.

However, these side-effects tend to be mild and temporary, so they might not be a reason to avoid trying ED medication. For most men (and their partners), the benefits outweigh the risks. 

Some potential side-effects include headache and dizziness, hot flushes, indigestion, blurred vision, and nasal congestion. It’s essential to read the full patient information leaflet with each medication order to make sure you’re not at a heightened risk.

What are the differences between Viagra and Sildenafil?

With all of the similarities we’ve listed, you might be wondering what’s left that could be different between the two drugs. In truth, the differences are minimal and mostly trivial in nature. 

The main difference between Sildenafil and Viagra is the price. Branded Viagra tablets, thanks to their high-profile name, regularly cost over three times as much as the unbranded Sildenafil. While some may prefer to pay the high price for the familiar brand name, there is no practical or medical reason to do so.

A lower price for medication (especially when ordered online) might ring alarm bells for some people, but credible licensed suppliers are legitimately able to supply these drugs for cheaper. Indeed, it’s right that you should expect to pay less for Sildenafil when compared to Viagra.

The other difference between Sildenafil and Viagra can be the appearance of the tablets themselves. While much of Viagra’s recognition comes from being the distinctive small, blue, diamond shaped pill, Sildenafil can come in various guises: blue, white, oval, round or diamond-shaped.

Are There Other Medications Available for Erectile Dysfunction?

Yes, there are other branded and generic medications available in the UK for ED. For example, Tadalafil is the generic version of the brand Cialis, Vardenafil is the unbranded version of Levitra, and Avanafil is the generic version of Spedra. All of these drugs are PDE5 inhibitors, so they all work in a similar way to Sildenafil and Viagra to help men with erectile dysfunction.

Cialis (Tadalafil)

The weekend pill

Known as the “weekend pill” because it is effective for up to 36 hours, Tadalafil is the generic, unbranded version of Cialis. Clinically proven to help you get an erection when you need it.

Best for
Weekend use
Effective in
Effective in 8 out of 10 men
2.5mg, 10mg, 20mg

Key takeaways…

So there you have it. While public awareness and knowledge of Viagra and Sildenafil couldn’t be more different, there actually isn’t anything between them medically. Sildenafil is as good as Viagra, and the fact that it is a cheaper alternative shouldn’t create doubt about its legitimacy as a great ED treatment. 

Although a common problem in the UK, erectile dysfunction isn’t something you need to accept as a fact of life. You can combat this condition with safe, reliable, and medically-approved drugs – ordered online for an affordable price. Sildenafil is a game-changer.

Erections aren’t always easy for millions of men in the UK. It’s no big deal. Choose from highly effective, clinically proven solutions.


Is it okay to take Viagra or Sildenafil?

If you suffer from erectile dysfunction (ED) then it is absolutely okay to take the prescribed amount of either Viagra or Sildenafil (both work the same). However, it is not safe or healthy to take ED medication if you have not been prescribed it, or do not suffer from erectile dysfunction. Recreational ED medication use can be harmful to your physical and mental health.

Who invented Viagra?

Sildenafil, the active ingredient in Viagra, was invented by American pharmaceutical company Pfizer in the 1980s. In 1998, Pfizer patented their Sildenafil medication as Viagra. However, now that the patent has expired, Sildenafil is available as a generic, unbranded ED medication. It works exactly the same as Viagra; Viagra is the brand and Sildenafil the active ingredient in it.

How does erectile dysfunction medication like Viagra and Sildenafil work?

Viagra and Sildenafil both work by inhibiting the PDE5 enzyme, which controls muscle contraction in the penis. The drug allows the blood vessels in the penis to relax and expand, boosting the blood flow to the area and making it easier to maintain a lasting erection.

What is the difference between Sildenafil and Viagra?

The only real difference between Sildenafil and Viagra is the price and appearance. Because Viagra is an established brand, it is considerably more expensive than Sildenafil, which comes in different shapes and sizes, but is unbranded and generic. If you have an option between the two, we say go with what’s cheaper! Both are safe and medically-approved for ED sufferers to take.

While we've ensured that everything you read on the Health Centre is medically reviewed and approved, information presented here is not intended to be a substitute for professional medical advice, diagnosis, or treatment. It should never be relied upon for specific medical advice. If you have any questions or concerns, please talk to your doctor.

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