To answer this question, it is important to understand exactly what these drug brands contain, and why they were developed in the first place.

The active ingredient in both Propecia and Proscar is finasteride. Both are manufactured by Merck Pharmaceuticals and the ingredient finasteride was developed to cure an enlarged prostate in men. It was only during clinical trials for Proscar that Merck realised that some of their test subjects were experiencing a reduction in their rate of hair loss.

Proscar contains a 5mg dose of finasteride. Upon further investigation Merck found that a 1mg dose of finasteride was sufficient to provide the same benefits to those with hair loss, so the 5mg Proscar product was marketed for an enlarged prostate, and a 1mg version called Propecia was born for the hair loss market.

propecia and proscar side by side

So in other words, the only difference between Proscar and Propecia is the dose of active ingredient finasteride.

If Proscar is stronger, is it better for hair loss?

No. Taking a 5mg (Proscar) dose of finasteride offers no additional benefits for those with hair loss, than a 1mg (Propecia) dose.

Why do some people buy Proscar?

In the context of hair loss prevention, some people prefer to buy Proscar, usually for one of two reasons:

  • They ignore the advice stating that Propecia is just as effective, believing that Proscar will benefit them more due to the increased dosage.
  • They buy Proscar and divide the tablets into smaller pieces, with the aim of getting the same dose for a lower cost.

In theory there is nothing wrong with buying Proscar and cutting the tablets, however this approach means you can never be sure of what dosage you’re actually getting. If you want to prevent balding, Propecia is the recommended drug.

What about side effects?

Finasteride, the active ingredient in both Propecia and Proscar, is linked with severe side effects. These side effects include impotence and erectile dysfunction.

Not everyone experiences side effects, in fact the majority of people do not, however the proportion that do is enough to cause serious concern. Merck is one of the worlds most sued companies, with many users taking legal action following severe side effects that they believe were not made clear enough at the point of sale.

Is Propecia or Proscar best for preventing hair loss?