Masculine hormones are referred to as androgens; the most well-known of these are testosterone and androstenedione. Despite their name, these hormones are present in females as well as males, and they are essential for maintaining the right hormonal balance.
In females, androgens are involved in puberty; they synthesise oestrogen, which along with progesterone, is one of the principle female sex hormones. Androgens are also involved in enhancing a women’s libido and maintaining a healthy reproductive system. The importance of female androgens is demonstrated by the ill effects that are felt when their synthesis is disrupted in any way.
An androgen deficiency in females can cause reduced libido, fatigue and a general lowering of mood. It can also make women more susceptible to osteoporosis, putting them at increased risk of bone fractures. Most women experience a lowering of androgen levels as they age, with levels dropping noticeably when they enter the menopause. It is not uncommon for blood androgen levels to fall by half after the menopause. This can be a particular problem for women who experience premature menopause or undergo a hysterectomy/oophorectomy. Hormone replacement therapy is one option for moderating the effects of reduced endogenous hormone production.
Some women experience the opposite problem; they have an excess of androgens, which is termed hyperandrogenism. The clinical signs of this include increased circulating testosterone, acne, hirsutism and alopecia (a type of male-pattern hair loss). Excess androgens can have a long-term effect on health, increasing the risk of conditions including diabetes, high blood pressure and heart disease, but they can also impact significantly on a woman’s self-confidence.
There are a number of recognised causes of hyperandrogenism, these include:
Some birth control pills have a high content of testosterone-like synthetic hormones called progestins. These can cause acne, hair loss and other masculinising symptoms.
Hypersensitivity of the androgen receptor
The receptor has an abnormal response to ‘normal’ levels of androgen, meaning that the dermatological symptoms of androgen excess are present, but blood samples do not reveal an increase in circulating androgens. The reasons for this are unclear; genetics, inflammation around the androgen receptor and elevated prolactin are all possible mechanisms. As is a post-pill surge in androgens, which sometimes occurs once women stop taking oral contraceptives.
Adrenal androgen excess
50% of androgens are produced by the adrenal gland. In cases of adrenal androgen excess, levels of testosterone and androstenedione are normal, but adrenal androgens are high. One cause is late-onset congenital adrenal hyperplasia (CAH), which is often misdiagnosed as polycystic ovary syndrome (PCOS). CAH is an inherited disorder where enzymes that are normally responsible for cortisol production are missing or ineffective. Symptoms typically include irregular periods, acne and hirsutism. It also causes higher than normal progesterone and may impair fertility. Treatment should be individualised on a patient-by-patient basis dependent on specific symptoms. Other causes of androgen excess are increased psychological stress and endocrine disruptors. Endocrine disruptors are a cause of great concern, due to their widespread prevalence. They are found in a large number of everyday cleaning and beauty products and they exert their detrimental effects by upsetting the normal hormonal balance (see below for further information on endocrine disruptors).
PCOS is best characterised as a range of symptoms that give rise to disrupted ovulation, hyperandrogenism and polycystic ovaries. For a clinical diagnosis, most guidelines stipulate that at least two of these symptoms should be present. PCOS can cause an overproduction of testosterone by the ovaries. The best treatment for PCOS is to identify the underlying cause and manage that.
These pose a risk because not only do they affect women, but many of them can also cross the placental barrier, creating a potentially harmful hyperandrogenic foetal environment. Long-term effects are unclear, but future metabolic and reproductive disorders are a concern.
Two well characterised examples of endocrine disruptors that have androgenic activity are TCC (triclocarban) and nicotine. TCC is an antimicrobial found in, amongst other products, soaps, clothing, carpets and plastics. It does not directly increase androgen levels, but does increase the activity of testosterone by increasing the action of the androgen receptor. Nicotine is found in cigarettes and can cross the placental barrier, accumulating in the amniotic fluid. Women smokers have increased testosterone levels, an effect exacerbated in those who have PCOS.
The take home message for women who are experiencing masculinisation due to excess androgens is to identify the root cause. This gives them the best basis on which to find a way to manage their symptoms.
- Hewlett, M, et al. “Prenatal Exposure to Endocrine Disruptors: A Developmental Etiology for Polycystic Ovary Syndrome.” Reproductive Sciences, vol. 24, no. 1, Jan. 2017, pp. 19–27., doi:10.1177/1933719116654992.
- Witchel, S F. “Nonclassic Congenital Adrenal Hyperplasia.” Current Opinion in Endocrinology, Diabetes and Obesity, vol. 19, no. 3, June 2012, pp. 151–158., doi:10.1097/MED.0b013e3283534db2.
- “Androgen.” Healthy Woman, www.healthywomen.org/condition/androgen.
- Briden, L. “4 Causes of Androgen Excess in Women.” Lara Briden – The Period Revolutionary, 6 July 2015, www.larabriden.com/causes-androgen-excess-in-women/.
- Galan, N. “Late-Onset Congenital Adrenal Hyperplasia .” Very Well Health, www.verywellhealth.com/congenital-adrenal-hyperplasia-overview-2616550. Updated December 20, 2018.