Finasteride For Women

If you’re a woman experiencing hair loss, you have probably been researching which hair loss treatment is right for you. Finasteride is a common DHT-blocking medication used to treat androgenetic alopecia (pattern hair loss) in men. However, finasteride has been known to have adverse effects on women. Keep reading for more information on finasteride, hair loss in women, and what treatments exist for female hair loss.

Overview

• Finasteride is a DHT-blocking medication used to treat pattern hair loss (androgenetic alopecia) in men. This hair loss medication prevents DHT molecules from binding to androgen receptors on the scalp, limiting hair loss and maintaining hair growth.
• Finasteride is not recommended for use by women. This is because scientific research has shown the medication is ineffective at treating hair loss in women and poses health risks to pregnant women.
• Several other medications and treatments exist to help women experiencing hair loss. Instead of taking finasteride, female hair loss patients may want to consider alternatives such as minoxidil for hair loss, PRP therapy, or hair transplant surgery.

First Things First: What is Finasteride?

If you’re experiencing hair loss, then you have probably heard of “finasteride“. Whether you have been doing some research into hair loss treatments or have been advertised medication on social media, finasteride is often one of the first (and most popular) treatments marketed to potential patients.

Finasteride was first developed as a medication to help treat benign prostatic hyperplasia (prostate enlargement) in men. It was first approved for use in 1992 and is freely available as a prescription medication for men in the UK and US.

In recent years, scientific research into finasteride has shown it to be an effective medication for treating a hair loss condition called male pattern baldness. This is because finasteride inhibits the uptake of Dihydrotestosterone (DHT), a powerful male sex hormone known to cause pattern hair loss.

Finasteride is proven to be one of the most effective hair loss treatments available for men. In a 1999 study of nearly 2,000 men over two years, 83% of men reported no further hair loss after taking 1mg finasteride continuously [1]. This led the researchers to conclude:

Oral finasteride promotes scalp hair growth and prevents further hair loss in a significant proportion of men with male pattern hair loss. With its generally good tolerability profile, finasteride is a new approach to the management of this condition, for which treatment options are few [1].

Despite finasteride’s proven efficacy at treating hair loss in men, scientific research has shown the 5a-reductase inhibitor to be less effective at treating hair loss in women. Furthermore, finasteride is suggested to pose harmful side effects for pregnant women. It is for these reasons that finasteride is not recommended for women.

How Does Finasteride Work?

Finasteride is a medication called a 5a-reductase inhibitor (5-AR). 5-ARs work by decreasing the production and uptake of dihydrotestosterone (DHT) in the body.

DHT is a powerful hormone predominantly responsible for developing and maintaining male sex characteristics like lean muscle mass, a deep voice, and facial/beard hair growth. However, it has also been shown to cause head hair loss in men.

By preventing the production of DHT in the body, fewer molecules can bind to androgen receptors on our hair follicles. In turn, this reduces a process called telogen effluvium from occurring, which causes hair follicles to shed and miniaturise.

So, reducing levels of DHT in the body, by way of proxy, prevents hair loss from occurring. In other words, DHT-blockers stop hair loss at source.

Hair Loss in Women and Men: What Are the Differences?

In the previous section, we mentioned that finasteride is scientifically proven to be effective at treating male pattern baldness. This is because finasteride helps lower the production of DHT in the body, thus reducing pattern hair loss on the hairline and crown. DHT has been shown to play a leading role in male hair loss. But what about women?

Well, hair loss in women is a far more varied and complex topic than in men. Around 50% of all men will experience symptoms of male pattern baldness by the age of 50 [2]. Overwhelmingly, androgenic alopecia accounts for almost all hair loss conditions in men, excluding hair loss from autoimmune conditions (alopecia areata).

Comparatively, androgenic alopecia is believed to affect around 1/3 of women by the age of 50 [3], suggesting it to be a less prevalent condition in females than males. Furthermore, this condition is typically present in women at a later age (50+) than men (25+). This means that there are several other causes of hair loss in women.

In younger women, hair loss is often caused by environmental or hormonal factors. Post-partum hair loss (hair loss after childbirth), hair loss from stress, and dietary deficiencies are the most common explanations for female hair loss below the age of 50. These conditions also tend to cause temporary hair loss, meaning medical treatments are often not required.

Other causes of hair loss in women are cases of “traction alopecia” and “scarring alopecia”. These conditions are caused by excessive pulling on the hair follicles from harsh styling practices. One study estimates that around 2.7% of women in the US suffer from traction alopecia [4]. Further research into this condition shows traction alopecia disproportionately affects women of African descent (around 30%-40%: [5]) due to the prevalence of styling practices such as dreadlocking.

Why Are DHT-Blockers Less Effective at Treating Pre-Menopausal Hair Loss?

The main reason why DHT-blockers like finasteride and dutasteride are less effective at treating women’s hair loss is because DHT performs a less important role in female endocrinology. Women of fertile age have much higher levels of female sex hormones like oestrogen and progesterone than male hormones.

DHT levels in men are, on average, much higher than in women. Typically, DHT levels in men stand at around 30-85 ng/dL [6]. For women, DHT levels typically range from 4-22 ng/dL [6]. With a much lower concentration of DHT in the body, it is no surprise that fertile women tend not to suffer from female pattern hair loss before hormonal imbalances are caused by menopause.

This means that hair loss conditions younger women experience are often not caused by DHT. So, prescribing DHT-blocking medications such as finasteride for women would be pointless as it would not stop them from losing hair. Alternative treatments, such as minoxidil or PRP therapy, would be more suitable in these instances.

It is only once a woman has gone through the menopause that DHT levels appear elevated. Although, this is not typically due to increased male sex hormone levels. Rather, its prevalence is due to lower levels (by comparison) of female sex hormones that were once required for the menstrual cycle, pregnancy, and the development of secondary sex characteristics.

Could Finasteride Be Used For Postmenopausal Women Experiencing Female Pattern Hair Loss?

As post-menopausal women have a higher concentration of DHT levels than pre-menopausal women, this explains why female pattern baldness usually presents in women over 50. The increased prevalence of DHT increases the likelihood of binding to AR receptors on the scalp, resulting in female pattern hair loss.

As postmenopausal women cannot get pregnant, one of the most detrimental side effects of finasteride use in women (foetal deformity) is negated. This means that finasteride may be safe to use for women who have gone through the menopause.

In a recent study conducted by Drug Design, Development, and Therapy Journal (2020), results showed oral finasteride to be an effective treatment against female androgenetic alopecia in postmenopausal women [7]. Furthermore, topical finasteride and second-generation DHT-blockers (dutasteride) also show increased hair growth.

Currently, finasteride is not an authorised hair loss treatment for women in the UK or US. The study conducted by DDDT remains one of the only scientific studies on this issue and more research is needed to prove the efficacy and safety of finasteride for women.

Finasteride Has Negative Side Effects For Pregnant Women: Finasteride and Foetal Sexual Development

Perhaps the most important reason why finasteride is not recommended for women is due to some of its harmful side effects in pregnant women. Research has shown that finasteride use in pregnant women may result in birth defects.

Studies on this topic have been conducted on animals, and results have shown that exposure to large doses of finasteride while pregnant leads to increased chances of birth defects of sex organs in male offspring [8].

While a 2018 case study that followed a woman who took finasteride during pregnancy resulted in no internal or external birth defects of her infant [9], it is important to note that a single case report does not necessarily mean that finasteride is safe to use for pregnant women.

While there is little evidence definitively showing pregnant women taking finasteride to have had babies with birth defects, results of previous animal studies show that more research needs to be conducted on this issue to prove the safety of finasteride.

Secondary Side Effects of Finasteride Use

Aside from the potential risks finasteride poses to foetal development, finasteride also poses other common side effects that ought to be considered before a person takes the medication for hair loss. Common side effects of finasteride include:

• Decreased libido
• Menstrual irregularities
• Headaches
• Mood changes
• Body hair growth

If you are a woman taking finasteride to treat hair loss and you are experiencing one of these side effects, you should consult a GP or hair transplant surgeon immediately.

What Hair Loss Treatments Can Women Take Instead of Finasteride?

If you’re a woman experiencing thinning hair, then there are alternative hair loss treatments. These include, but are not limited to:

Topical Minoxidil

Topical minoxidil (Rogaine) is a foam-like treatment that stimulates hair growth. When massaged into the head, minoxidil increases blood flow around the scalp and ensures hair follicles receive enough oxygen and nutrients.

In doing so, this helps to prolong the anagen (growth) phase of the hair growth cycle, fending off the “catagen” (shed) and “telogen” (resting) phases. As long as a patient keeps taking minoxidil, they will maintain their hair density and slow down signs of hair loss.

Minoxidil is a fantastic option for any woman experiencing early signs of hair loss. It is safe to use, effective at treating thinning hair, and freely available to buy over the counter at any pharmacy or supermarket.

PRP Therapy

Platelet-Rich Plasma (PRP) Therapy is a non-invasive treatment that involves injecting a patient’s own platelets into their scalp to promote hair growth. A centrifuge is used to split plasma from the blood. From here, plasma is injected into the scalp and this promotes new hair growth.

While results show PRP to be an effective hair loss treatment that is safe for women, it is expensive. Furthermore, the treatment is only effective for as long as a patient continues with it. As such, better alternatives do exist.

Hair Transplant Surgery

If you’re a woman experiencing hair loss, the only real way to “reverse” or “restore” your original hair is through a hair transplant. Hair transplantation takes hair follicles from the back and sides of the head and moves them to an area of the scalp where they are needed.

Hair transplants are ideal for women grappling with medium to extensive hair loss. When combined with topical treatment as part of an aftercare routine, a woman can see significant improvement in hair growth for many years after surgery.

Conclusion

So, can women take finasteride? The answer to this question complex and is dependent upon several factors. Finasteride is a powerful DHT-blocking medication that is clinically proven to stop male pattern baldness. Preliminary scientific research has shown finasteride my also be effective at treating female pattern hair loss (FPHL) in post-menopausal women.

However, it is also important to consider that the causes of female hair loss are varied and not always caused by DHT. This may limit the efficacy of finasteride in premenopausal women. Finasteride may also pose risks to foetal development. For this reason, it is not approved for use in the UK or US.

References:

1.  McKlellan, K J. “Finasteride: a Review of its Use in Male Pattern Hair Loss”. Drugs. 57(1) (1999) <https://pubmed.ncbi.nlm.nih.gov/9951956/>.
2. Asfour, L. “Male Androgenetic Alopecia”. Endotext. (2023) <https://www.ncbi.nlm.nih.gov/books/NBK278957/>
3. Anon. Treating Female Pattern Hair Loss”. Harvard Health. (2024) <https://www.health.harvard.edu/staying-healthy/treating-female-pattern-hair-loss/>
4. McQuistan, A. “Incidence of Alopecia and Hair Loss Among Female Active Component Service Members, 2010-2022”. MSMR. 20(31) (2024) <https://pubmed.ncbi.nlm.nih.gov/39413275/>
5. Khumalo, N P. “Determinants of Marginal Traction Alopecia in African Girls and Women”. Journal of the American Academy of Dermatology. 59(3) (2008) <https://pubmed.ncbi.nlm.nih.gov/18694677/>
6. Anon. “Endocrinology: Expected Values”. LabCorp (2020) <https://web.archive.org/web/20200330030510/https://www.esoterix.com/sites/default/files/L5167-0320-17.pdf>.
7. Iamsumang, W. “Finasteride and its Potential for the Treatment of Female Pattern Hair Loss: Evidence to Date”. Drug Design, Development, and Therapy Journal. 2(14) (2020) <https://pmc.ncbi.nlm.nih.gov/articles/PMC7060023/#S0007>.
8. Bowman, C. “Effects of in Utero Exposure to Finasteride on Androgen-Dependent Reproductive Development in the Male Rat”. Toxicological Sciences. 74(2) (2003) <https://academic.oup.com/toxsci/article-abstract/74/2/393/1716348?redirectedFrom=fulltext&login=false>.
9. Al Saad, D. “Finasteride Use During Pregnancy and Early Neonatal Outcome: a Case Report”. International Journal of Clinical Pharmacology. 40(4) (2018) <https://pubmed.ncbi.nlm.nih.gov/29855987/>.