Hair Metrics Analysis: Finasteride and Dutasteride

Finasteride (Brand Names: Proscar ®, Propecia ®) and Dutasteride (Brand Name: Avodart ®)

Most Hair Metrics customers are familiar with the once-per-day prescription pill for hair loss known as Propecia® (among other names), but this medication (finasteride), and its sibling dutasteride, first and foremost are for the treatment of enlarged prostate, and finasteride has been used as such since 1992 when approved by the FDA.

In particular, this medication has been shown to be effective for treating a variety of urinary symptoms associated with prostate disease. It was only years later that the clinical tests showed patients experiencing hair growth as a side effect of the medication.

Specifically, this drug inhibits the enzyme 5-alpha reductase, and thus prevents conversion of testosterone to dihydrotestosterone (DHT), a hormone which causes follicles to shrink and eventually lose the ability to grow new, thick hair. As a result of taking the drug, men’s (and some women’s!) testosterone levels rise along with their hair, as long as the user continues taking the drug.

Our Take…

We’ll spare you our safety rant about taking any prescription medication indefinitely for elective reasons for longer than their FDA trials, and to be fair, studies claim that side effects of this medication are rare, at least for the time period examined. However, it should give you some pause that there’s actually a foundation set up to help treat and inform people about what has been termed “post-finasteride syndrome,” or the cluster of sexual and other side effects in men including erectile dysfunction, loss of desire, and loss of sensitivity that continue to occur during and even after stopping the medication.

Oh, and not only is finasteride less effective in women, but women who may become pregnant or are pregnant are advised to avoid even touching the tablets as they may cause birth defects. That’s comforting. But, it may be worth the sacrifice for a full head of hair, right? Perhaps, but the data suggest (see below) that you won’t get that with finasteride, and dutasteride is still not FDA approved for hair loss.

According to a 2013 review of finasteride in a Harvard Law publication, 5 years of committed use of Propecia will likely get you only a 10% improvement over doing nothing, or an increase in the number of hairs by 2%. Most of the effectiveness is only in slowing down hair loss. Does that not excite you? Us neither. Hard pass.

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