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.
Finally, I’ll highlight a few alternative treatment options for 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).
But why does this work?
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.
Finasteride doesn’t prevent testosterone or DHT from performing their necessary biological processes. However, it does reduce the amount of DHT present in the body which can be beneficial for those with AGA and similar conditions.
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). Women affected by PCOS (Polycystic Ovarian Syndrome) will also be affected by pattern balding. This is thought to be caused by low progesterone and insulin resistance.
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.
Study: Lack of efficacy of finasteride in postmenopausal women with androgenetic alopecia (2000)
This first study, performed in Portugal and published in 2000, consisted of 137 postmenopausal women (between 41 and 60 years of age) with diagnosed AGA (7).
The study was carried out over one year, and it can be classified as a double-blind, placebo-controlled, randomized, multicenter trial.
The women were split into two groups, of which one received a daily dose of 1mg finasteride and the other received a placebo. This continued for 12 months, and the methods used for evaluation included:
- Scalp hair counts
- Patient and investigator assessments
- Assessment of global photographs by a blinded expert panel
- Histologic analysis of scalp biopsy specimens
How did the women fare?
According to the study, “after 1 year of therapy, there was no significant difference in the change in hair count between the finasteride and placebo groups.” In fact, both groups showed significant decreases in hair count in the frontal/parietal scalp.
Even further, “the scalp biopsy analysis did not demonstrate any improvement in slowing hair thinning, increasing hair growth, or improving the appearance of the hair.”
This study very clearly demonstrated that the women did not benefit from finasteride therapy, but a few later studies say otherwise.
Study: Finasteride treatment of patterned hair loss in normoandrogenic postmenopausal women (2004)
A 2004 study performed in Switzerland tested the effects of 2.5mg and 5mg finasteride on five postmenopausal women over a span of 18 months (8).
The efficacy of the drug was evaluated by patient and investigator assessments, as well as a review of photographs taken at baseline and at months six, 12 and 18 by an expert panel.
As the results of this study indicate, the 2.5mg dose of finasteride was enough to decrease hair loss, increase hair growth, and improve the appearance of hair within 18 months of use. Even further, there were no adverse effects reported.
Do keep in mind that assessments were subjective and, as such, cannot be held up as proof of finasteride’s positive effects on pattern loss in women. In addition, the sample size was quite small.
Fortunately, there is another more recent study with an objective study design.
Study: Finasteride 5 mg/day treatment of patterned hair loss in normo-androgenetic postmenopausal women (2013)
Finasteride is a drug that’s available in various dosages. And while it’s important to use the lowest dose possible so as to reduce the risk of adverse effects, researchers have studied various dose strengths on women to determine true efficacy of the drug (9).
In one particular study, published in 2013, researchers wanted to see how effective (or not) a 5mg/day dose of finasteride would be on postmenopausal women with AGA.
A total of 40 women participated in this study, and all of them received a daily dose of 5mg finasteride for a 18 months.
The efficacy of the treatment was evaluated by patient’s satisfaction, as well as global photograph assessment by two independent dermatologists.
After 6 months, 22 patients referred significant improvement, 12 referred moderate improvement, and 6 referred no improvement. These were somewhat in line with the photograph assessments of which the dermatologists determined that 8 patients showed no improvement, 16 showed moderate improvement, and 16 showed significant improvements at the 6th month
A slight improvement was observed from the 6th month to 12 and 18 months.
While the results were not as objective as desired, they do strongly suggest that 5mg finasteride “is effective and safe for the treatment of female AGA in postmenopausal women in the absence of clinical or laboratory signs of hyper-androgenism.”
The study also showed that the participants experienced minimal adverse effects with four reporting sustained reduced libido and one experiencing elevated liver enzymes.
Can Finasteride Be Used for Female Pattern Hair Loss?
Now that we’ve considered the scientific data, it’s time to answer the big question: can finasteride be used for female pattern hair loss?
The answer, unfortunately, is unclear.
As stated previously, finasteride works by inhibiting the activities of 5AR which is why the drug works so well in men with AGA. However, not all women with AGA have high androgen levels and, because of this, it makes sense that they wouldn’t respond to the treatment.
But that’s not to say that positive results aren’t possible.
As highlighted by the three studies above, there is proof that an oral daily dose of finasteride may contribute to decreased hair loss and increased hair growth. However, further research is needed to determine which dose is most effective with the least risk of side effects.
It would also be helpful to see longer-term studies on pre-menopausal women which take into account the possible benefits of oral contraceptive. The researchers could then filter the results more effectively so as to improve the transparency of the results.
Are There Other Options?
If finasteride isn’t currently an option for women suffering from thinning and loss, what other options exist?
Perhaps the most common drug used in the treatment of female pattern hair loss is minoxidil (Rogaine). This solution was first developed as an oral drug for the treatment of hypertension but, just like finasteride, the side effect of hair growth was soon discovered (10).
The drug was re-released as the topical solution Rogaine in 1984 for the treatment of male-pattern hair loss, and it was soon made available to women in 1991.
Minoxidil is believed to have a variety of mechanisms, including the stimulation of blood flow and up-regulation of certain growth factors (11, 12). This is likely why it’s popular for men and women alike.
Another option, though one that’s less well known is spironolactone.
Spironolactone is an oral drug that works somewhat similar to finasteride. It does reduce the activities of 5-alpha-reductase, but it does so by blocking androgens (including testosterone) (13).
This drug is more often prescribed for women than men, though it technically has not been approved for use in hair loss.
Whether used instead of, or in conjunction with, the drugs mentioned above, one option that doesn’t get enough attention is manual stimulation.
In short, manual stimulation is the physical manipulation of your scalp using your fingertips or specially-designed tools such as a brush or dermastamp. These techniques work by increasing blood flow to the area which can combat follicle miniaturization and even promote hair growth (14, 15).
This is a great option for those who are unable or unwilling to take minoxidil and/or spironolactone, or those who want to boost the hair growth they’re seeing with the aforementioned drug treatments.
Over the past 20 years, there have been numerous studies performed to gauge the efficacy of finasteride in female pattern hair loss. The results have been varied and, as such, the drug has yet to be approved for use in women.
That doesn’t mean that women with thinning and alopecia have no other options, though.
Minoxidil (Rogaine) and spironolactone are used widely by women with hair loss to slow shedding and induce growth. And alternative options – such as scalp massage and microneedling – also exist.
But when it comes right down to it, the fact of the matter is you need to treat the underlying cause of your condition if you want to stop hair loss and perhaps even regrow your hair.