Finasteride is a drug that’s popularly known for its use as a treatment for hair loss in men, but what about women?
In this post, I’ll dive introduce finasteride and how it works. I’ll connect the dots between Androgenetic Alopecia (AGA) and female pattern hair loss, and I’ll also discuss the various scientific studies that outline the use of finasteride in the treatment of alopecia in women.
What is Finasteride?
Finasteride, more commonly known by its brand name Propecia, is an oral drug used in the treatment of Androgenetic Alopecia (AGA) (1).
The drug was originally developed for use in Benign Prostate Hyperplasia (BPH), and it was FDA approved for this purpose in 1992 under the name Proscar.
However, an unexpected side effect of its use was hair growth. This led to the development of Propecia which was approved by the FDA for prescription use in 1997.
How Does It Work?
Finasteride is a synthetic azo-steroid that works by inhibiting the activities of type II 5 alpha reductase (2). It is not an anti-androgen, but it instead binds to the enzyme and inhibits the natural conversion of testosterone to dihydrotestosterone (DHT).
Androgenetic alopecia, also referred to as pattern hair loss, is believed to be caused by a sensitivity to the androgen DHT. This sensitivity triggers follicle miniaturization when the androgen attaches to the follicle’s receptors and this, in turn, can lead to shedding and hair loss.
AGA and Female Pattern Hair Loss: A Link?
Androgenetic alopecia is often considered to be a male-only condition, but that’s simply not true. While AGA is often referred to as male-pattern baldness, the condition can affect women, too.
In fact, pattern baldness can occur in over 50 percent of women over the age of 80 and it can start as early as 20 with an incidence rate of 12 percent (3).
The histological hallmark of pattern hair loss in both men and women is follicle miniaturization. And while the cause of this miniaturization in men is strongly linked to androgens, the link between androgens and female pattern hair loss isn’t so clear (4).
There are some women who have elevated levels of androgen in their blood serum and hair follicles which is similar to how the condition presents in men. However, there are also those women who don’t have elevated androgen levels which indicates that the problem is likely independent of androgens entirely (5).
Finasteride for Women: The Scientific Evidence
Since 1997, finasteride has been used exclusively in men for the treatment of AGA. However, the drug has yet to be approved for use by women who are suffering from the same condition.
The main reason for this is that finasteride is classified as a “Category X” drug which means it has high potential to cause serious harm to fetuses. As such, use in women of child-bearing age is extremely risky, and the benefits don’t outweigh the negatives.
While studies have been performed on the use of finasteride in pre-menopausal women, the caveat is that these women were also on an oral contraceptive (6). Therefore, there is no way to prove that finasteride alone was responsible for the results seen.
But those aren’t the only studies to have been performed.
Studies performed on postmenopausal women are also available for review, and these offer a more in-depth look at the effects of finasteride on female-pattern alopecia.