What is Propecia? Does it Work?

Below is a Q/A with our lead hair transplant surgeon!

What are your initial thoughts on Propecia (Merck)?

We recommend Propecia to all of our male hair loss patients. It does a great job of preserving and even thickening up existing hair. It protects the native hair and does a great job of slowing down the thinning and falling out process. Side effects are relatively rare, so it is a safe drug to use and really is the gold standard for protecting the existing hair on the scalp.

What are some of the upsides to Propecia?

The main upside, and the reason so many men use it, is it protects and thickens the existing hair on the top of the head. For men with thinning hair, it can really slow down the loss and shedding of the hair. Some men respond very significantly and see a fair amount of rejuvenation of dormant follicles so it possible to see significantly more hair on the top of the head after using Propecia.

What are some of the downsides to using Propecia?

The most common reason people avoid Propecia are the possible side effects. It is possible to see sexual side effects, with the most common side effect a decrease in libido or sex drive. This occurs in anywhere from 5-8% of men who take Propecia. The next most common side effect is erectile issues and these occur in about 3-5% of people. The side effects are relatively infrequent, but they can occur so are worth monitoring for when taking the drug.

How exactly does Propecia work?

Propecia block the enzyme 5alpha-Reductase which is responsible for the conversion of testosterone to dihydrotestosterone (DHT). DHT binds to the hair follicle and shrinks the hair down over time to the point the follicle is not able to grow a hair anymore. By having less DHT circulating in the blood stream, less DHT binds to the hair follicle, which causes less shrinkage of the hair.

Who should use Propecia?

Any male with thinning hair or hair loss is in theory a candidate to use Propecia. It is important to be educated about possible side effects before starting the drug and talking to your doctor is the best way to make sure you are a good candidate to start taking Propecia.

What’s the difference between Propecia and Rogaine? What about generic finasteride?

Propecia is just the branded name for a specific dose (1 mg) of finasteride, so they are identical. Finasteride is the active drug in Propecia. Rogaine is the branded name for a different drug, Minoxidil. Propecia blocks the conversion of testosterone to dihydrotestosterone and thereby protects the hair. Minoxidil works in a different way, by dilating the blood vessels that run to the hair follicle. This increases blood flow to the hair, which allows it to grow stronger, faster and thicker and creates a healthier environment for hair growth.

Can women use Propecia?

It is possible for post-menopausal women to take Propecia, but there is somewhat limited evidence for its efficacy in female pattern loss. It is absolutely not recommended for any woman of childbearing age, whether she plans to be pregnant or not. The drug does cause fetal malformations or abnormalities and can cause loss of a fetus, so it is recommended to be avoided completely in any woman of childbearing age.

 How long does Propecia take to start working?

Propecia starts working very quickly, but to notice a visible difference in your hair can take up to three months. The effects usually build up to about 12 months or so and then begin to plateau. The hair is still being protected, but increased hair thickness may level out around 12 months or so.

Is there anything else you want to say about Propecia, male baldness, or hair rejuvenation in general?

There are many options to preserve and thicken hair, but Propecia is one of the best options. It works especially well when paired with other treatments and there are many preventative treatments out there that work well. It works best in existing areas of hair, and areas that are completely bald will need a more aggressive treatment, like a hair transplant.


As the highest-rated hair transplant company in Chicago, we encourage you to price shop around. We are confident that when the research is finished, the choice will be easy. If you’re ready to get going, you can schedule a free consultation here.

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