The Androgen Paradox of Hair Growth and Hair Loss

Androgens are male hormones and as explained below, contribute to hair growth in both men and women. But, androgens also contribute to hair loss, such as in androgenetic alopecia. This is known as the “androgen paradox”.

As explained in the previous article, one of the main contributors to both male pattern baldness and female pattern baldness, also known as androgenetic alopecia, is the hormone dihydrotestosterone (DHT). DHT is a male hormone (androgen) that is a metabolite of testosterone made by the enzyme  5 alpha-reductase (5-AR) acting on testosterone. 

But androgens also play an important role in hair growth.

The Androgen Paradox

Before people go through puberty, most parts of the body (except for the scalp) are covered in thin, fine hair known as vellus hair (“peach fuzz”). Vellus hair is generally lighter and shorter than terminal hair that grows on the scalp, which is longer and thicker [1]. As androgens increase during puberty, vellus hair follicles are change into terminal hair follicles which then produce larger, curlier, and darker hair which appears in the public area, and “arm pits” (axillary area) [1].

During puberty, androgens stimulate beard growth in men [1], but even though androgens such as testosterone, androstenedione, dehydroepiandrosterone (DHEA), and DHEA sulfate (DHEAS) are produced by the ovaries and adrenal glands of healthy women, these are not in large enough quantities to stimulate hair growth on the face. In women with Polycystic Ovarian Syndrome (PCOS) however, hair on the upper lip and chin area (hirsutism) is common and is believed to be due to high levels of male androgens and abnormal levels of luteinizing hormone (LH) from the pituitary interfering with the normal function of the ovaries [2,3].

Paradoxically, androgens also contribute to hair loss in androgenetic alopecia (AGA) [4].  A double blind control study from 1994 of people with androgenetic alopecia found that DHT levels were significantly higher in areas of bald scalp, than in areas of the scalp that contained hair [5]. In 1996, it was determined that the parts of the scalp that show balding in androgenetic alopecia have higher levels of the enzyme 5 alpha-reductase (5-AR) in the hair follicles, than the hair follicles in the parts of the scalp that do not bald [6]. These higher levels of 5-AR in the hair follicles converts testosterone to DHT, and when DHT binds to the receptors in the oil glands of hair follicles, it causes the follicles to shrink, or “miniaturize” until they eventually stop producing hair, resulting in baldness. 

As mentioned in the previous article, 5 alpha-reductase (5-AR) can be inhibited by the drug Finasteride® which lowers levels of DHT in the hair follicle, reducing the attack and slowing, or stopping hair loss.  Finasteride® also reduces the amount of DHT in the blood and scalp [7,8] and slowing androgenic alopecia progression.

As outlined in the first article in the three-part series titled, “Lotions, Potions, and Pills”, there are nutritional supplements available that are documented to restore hair growth and that are supported with the highest-quality evidence. A few of them are 5 alpha-reductase (5-AR) Inhibitors, and function similarly to Finasteride®.

The upcoming second article in the series will outline several oral hair growth supplement mixtures with the best quality scientific evidence to support hair growth — some of which also act as 5 alpha-reductase (5-AR) Inhibitors.

In addition, the third upcoming article in the series will outline evidence-based topical hair supplements that either serve as 5-AR reductase inhibitors to reduce the effect dihydrotestosterone (DHT) on hair follicles, support scalp health through their antibacterial or antimicrobial properties, or stimulate hair growth by increasing blood flow to hair follicles.

Final thoughts…

Androgens can paradoxically stimulate hair growth and cycling and this results in men having more hair on their face, and both men and women having hair in their pubic region and arm pits. Androgens can also contribute to balding on the scalp in the same individual, regardless of gender [9].

The balding effect of dihydrotestosterone (DHT) acting on hair follicles of the scalp can be reduced with use of medication treatment such as Finasteride®, as well as by evidence-based oral nutritional supplements and topical applications of essential oils, botanicals, and herbals.

While  Finasteride® is very effective at treating the hair loss associated with androgenic alopecia (as well as benign prostate hyperplasia (BPH)), its use is not without potential side effects. These can include decreased libido, the inability of men to have or maintain an erection, or problems with ejaculation [10]. 

Use oral nutritional supplements supported by robust scientific studies to promote hair growth and/or the use of topical applications of essential oils, botanicals, or herbals that have been demonstrated to be both safe and effective at reducing or stopping hair loss is also an available option.  Click here to read the first of three articles in a series on this topic.

More Info?

If you would like more information about how I could support you from a nutritional perspective, please send me a note through the Contact Me form at the top of this page.

To your good health!


You can follow me on:



    1. Inui, S., Itami, S. (2013). Androgen actions on the human hair follicle: perspectives. Exp. Dermatol. 22, 168–171. doi: 10.1111/exd.12024
    2. Barbieri RL, Ehrmann, DA. UpToDate Patient education: Polycystic ovary syndrome (PCOS) (Beyond the Basics), December 20, 2021,
    3. Abdelazim IA, Alanwar A, AbuFaza M, et al. Elevated and diagnostic androgens of polycystic ovary syndrome. Prz Menopauzalny. 2020;19(1):1-5. doi:10.5114/pm.2020.95293
    4. Randall, V. A. (2007). Hormonal regulation of hair follicles exhibits a biological paradox. Semin. Cell Dev. Biol. 18, 274. doi: 10.1016/j.semcdb.2007.02.004
    5. Dallob, A. L., Sadick, N. S., Unger, W., Lipert, S., Geissler, L. A., Gregoire, S. L., et al. (1994). The effect of finasteride, a 5 alpha-reductase inhibitor, on scalp skin testosterone and dihydrotestosterone concentrations in patients with male pattern baldness. J. Clin. Endocr. Metab. 79, 703–706. doi: 10.1210/jcem.79.3.8077349
    6. Itami, S., Nakanishi, J., Yoshikawa, K., Takayasu, S. (1996). 21 Expression of androgen receptor, type I and type II 5 α-reductase in human hair follicle cells. J. Dermatol. Sci. 12, 86–86. doi: 10.1016/0923-1811(94)90434-0
    7. Drake, L., Hordinsky, M., Fiedler, V., Swinehart, J., Unger, W. P., Cotterill, P. C., et al. (1999). The effects of finasteride on scalp skin and serum androgen levels in men with androgenetic alopecia. J. Am. Acad. Dermatol. 41, 550–554. doi: 10.1016/s0190-9622(99)80051-6
    8. Price, V. H. (1999). Treatment of hair loss. New Engl. J. Med. 341, 964–973. doi: 10.1056/NEJM199909233411307
    9. Miranda, B. H., Charlesworth, M. R., Tobin, D. J., Sharpe, D. T., Randall, V. A. (2018). Androgens trigger different growth responses in genetically identical human hair follicles in organ culture that reflect their epigenetic diversity in life. FASEB J. 32, 795–806. doi: 10.1096/fj.201700260RR
    10. MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); [updated 2022 Jun 15]. Finasteride, Available from: 

Copyright ©2022 BetterByDesign Nutrition Ltd.

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.