Comparing Viagra and Sildenafil (Generic): How Are They Different?

If you’ve heard of Viagra then you’ve probably heard of Sildenafil.

But do you know why the two names always come up together?

They’re very closely linked because they’re actually the same thing: Generic Viagra is Sildenafil. 

Here we’ll find out if Sildenafil is as good as Viagra and if there’s a reason why you might want to consider a switch to the Viagra alternative.

Sildenafil vs Viagra: What’s the difference?

Sildenafil and Viagra do the same job: they both contain the active ingredient sildenafil citrate. The difference is that Viagra is the well-known brand-name ED medication made by Pfizer. Whereas Sildenafil is the generic version and is made by a number of manufacturers. 

Pfizer held the exclusive marketing license for Viagra from its inception in 1998 until the patent expired in 2013. At this point other pharmaceutical companies were permitted to produce their own version of the medication. When that happens, this version is known as the generic. More often than not, the generic takes the name of the active ingredient, in this case Sildenafil.

For the treatment of ED, both Sildenafil and Viagra are produced in 25mg, 50mg and 100mg pills. Generic Viagra pills are formulated to work in the same way as brand-name Viagra. If you compare the active ingredients for generic Sildenafil vs Viagra, you’ll find that they are the same.

If production standards are kept the same across the board then both tablets should produce the same results.[1]

This is also true of the listed efficacy levels, side effects, contraindications and interactions of either Sildenafil or Viagra. They are the same and should therefore produce the same outcome whether you opt for the brand-name or the generic.

Page reviewed by:
Mr Craig Marsh
Mr Craig Marsh
Pharmacist Prescriber
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Last updated August 20, 2021

Price: Why is Sildenafil cheaper than Viagra?

So, now you know that Viagra and Sildenafil are basically the same, but there’s probably still one big question left on your mind. Why the big price difference? 

The brand-name medication, in this case Viagra, tends to be more expensive and that can be for a number of reasons.

The time and money spent on researching, developing and testing a new product is substantial. In order to recoup some of these costs, a pharmaceutical company will take out a patent on their product. The patent lasts for a set number of years. Once it expires, other companies can choose to sell the product under the generic name. This is usually at a cheaper price as they have not ploughed investment into the research and development side of things.

Pharmaceutical companies can also put a significant amount of investment into the marketing of a brand-name medication. However, this isn’t usually the case for the generic version.

Some people will prefer to stay loyal to their original brand-name medication, especially if they’ve been using it for a while, even if it is at a higher price point. Whereas others will want to take full advantage of the savings provided by the generic.

So you may remain loyal to Viagra if it’s been serving you well, or you may be swayed by the Sildenafil price because it does the same job.

Do Viagra and Sildenafil have different side effects?

On paper, Viagra and Sildenafil should not cause any different side effects because they’re essentially the same medicine. 

When a manufacturer applies to produce a generic medicine, they have to demonstrate bioequivalence. If this is achieved then a license can be considered. The manufacturer of the generic doesn’t have to prove its efficacy and in most cases will inherit the clinical data and study results from the original brand-name product.

This means that if you are using the brand-name medication and decide to switch to the generic, then you are unlikely to notice any new side effects.

However, there is some evidence to suggest that using a generic medication may increase the chance of experiencing side effects.[2] Also, anecdotally you may hear of some men preferring either the brand-name or the generic of a medicine.

Benefits of Viagra vs Sildenafil

Viagra and Sildenafil contain the same active ingredients and work in the same way. Any potential side effects are the same. So, there really isn’t much difference between the two. 

However, while Viagra and Sildenafil are the same on a bioequivalent level, one big difference that we’ve already mentioned is the price. For some, this is a huge benefit.

Sildenafil can be significantly cheaper than Viagra. If price is your main motivation then trying Sildenafil is definitely worthwhile. You could end up with the same bang for much less buck.

What other Sildenafil brand names are there?

While Pfizer is well-known for being the pharmaceutical company behind Viagra, there are different manufacturers making and supplying Sildenafil in its generic form. 

In the US generic Viagra is made by Teva, though Pfizer makes a generic version as well. Some pharmaceutical companies will actually manufacture and market the product. Whereas others only market the product.

Since the Sildenafil brand name can be used by different companies, you might not always get the same product when you buy generic Viagra from a pharmacy. It is understandable that some patients may develop a brand preference but it’s important to remember that supply issues can crop up. If you have questions about the types of Viagra stocked at EveAdam, please feel free to send us a message.

What does Generic Viagra look like?

Generic Viagra, or Sildenafil, does not look like the famous blue diamond Viagra pill. Instead it is a fairly innocuous, usually white, circular pill. The appearance of the generic Viagra brands can change depending on which manufacturer has made the pill.

The packaging and patient leaflets supplied with each Sildenafil brand can also look different.

It’s important to buy your ED pills through reputable sources so that you can be sure you are purchasing genuine products, whether they be brand-name or generic. 

Viagra dosages

The Sildenafil dosages used to treat ED are 25mg, 50mg and 100mg. The three different dosages are available so that a broader spectrum of men can use them. 

The 25mg dosage can be used by men who have experienced side effects on the 50mg dosage.

Example of a generic, white, round Sildenafil tablet
Blue diamond-shaped branded Viagra tablet

The 50mg dosage is the usual starting point for most men.

The strongest Viagra pill is Viagra 100mg and can be prescribed when the 50mg dosage hasn’t provided the best results but also hasn’t caused any side effects.

Viagra alternatives

Viagra and Sildenafil are not the only PDE5 inhibitor pills used to treat ED. There are several other options available if you’re looking for the best Viagra alternative. 

So, while Sildenafil is a direct Viagra substitute there are other medications to try if, for example, you’ve noticed side effects when taking the popular ED pills.

One of the strongest Viagra competitors is Cialis. When you pitch Cialis vs Viagra, you can see why some men prefer the pill that can last all weekend. Cialis can last up to 36 hours or there is an option to take a daily pill for those who prefer more spontaneous sex.

Another strong contender when pitted against Viagra is Levitra. The generic version of Levitra is Vardenafil. Both can be classed as Viagra-like pills as they fall into the PDE5i category.

Sildenafil, Tadalafil and Vardenafil are the generic versions of their brand-name counterparts, and are often found to be cheaper. Different drugs work in different ways for each of the people that use it. It can depend on how your body metabolises the drug and your susceptibility to side effects.

The only way to establish whether one drug works better than Viagra for you is to try each of them. It goes without saying that this should be carried out under the guidance of your healthcare professional.


[1] Publishing, H.H. (2018). Do generic drugs compromise on quality? [online] Harvard Health. Available at:

[2] Faasse, K., Cundy, T., Gamble, G. and Petrie, K.J. (2013). The Effect of an Apparent Change to a Branded or Generic Medication on Drug Effectiveness and Side Effects. Psychosomatic Medicine, 75(1), pp.90–96.