testosterone update

There’s plenty of confusion surrounding testosterone’s role in menopausal women, particularly whether testosterone therapy can be helpful.

Female testosterone production

Testosterone is an important hormone in both females and males. In females, it is produced in three locations.

1. The adrenal glands produce both testosterone and its precursors (compounds that can be converted to other hormones), accounting for about 50% of the total testosterone measured in the blood.
2. The ovaries contribute the remaining 50%. Ovaries produce testosterone both in follicle cells, where it converts to oestradiol, and in stromal cells surrounding the follicles. A mid-cycle peak of testosterone occurs following the LH surge at ovulation. After menopause, stromal cells continue to produce some testosterone.
3. Testosterone is produced locally within cells in various tissues like skin, fat, bones, and muscles, contributing to different and important cellular functions.

What happens to testosterone over the female lifespan?

Testosterone doesn’t decline abruptly at menopause like oestrogen does. In fact, evidence suggests that testosterone ‘activity’ increases around this time, leading to phenomena like hair loss, chin hairs, and facial ‘peach fuzz’. Testosterone falls from our 20’s, plateaus around midlife and shows a small up-kick around 70 years of age. Menopause IS NOT a testosterone ‘deficiency” state. In fact, during menopause, falling levels of oestrogen and progesterone leave testosterone unopposed in certain tissues, contributing to issues like scalp and facial hair loss, and perimenopausal acne. In addition, SHBG levels fall around menopause potentially resulting in an increase in bioactive (free) testosterone.

How do we interpret testosterone levels?

Approximately two-thirds of testosterone is tightly bound to sex hormone-binding globulin (SHBG), most of the rest is loosely bound to albumin, with about 1-5% circulating freely. The active effect on cells may be attributed to free testosterone, though this isn’t entirely confirmed. Testosterone activity within cells is crucial, where it and its precursors can be metabolised for unique cellular effects, and this testosterone is not reflected in measurable blood levels. Measuring low testosterone levels in females is technically challenging and often inaccurate. Blood levels are measured not to detect deficiency but to assess excess (e.g., in PCOS) or when considering testosterone therapy.

What do we know about testosterone therapy and health benefits?

There’s no medically identified condition solely linked to low testosterone in women. Women who undergo early oophorectomy (removal of the ovaries) experience around a 50% drop in testosterone but show no evidence of impaired bone health or other poor health outcomes despite this. The only medically approved indication for testosterone therapy in females is low libido, particularly hypoactive sexual desire disorder (HSDD) after other factors such as medications, relationship difficulties, past trauma etc have been addressed. Research has not shown significant benefits in general well-being, bone health, mood, energy, or cognition with testosterone therapy in women. While testosterone is anabolic and can promote muscle growth, it only does this when levels exceed the normal female range which can also lead to androgenic effects like increased facial hair and deepening of the voice.

Are there risks of using testosterone?

While much is known about the health benefits and risks of oestrogen and progestogen therapies, less is known about the long-term consequences of testosterone use in women. It’s unclear whether testosterone increases the risk of cancer, heart disease, or metabolic syndrome in females. Higher levels of testosterone are associated with greater visceral fat and lower HDL cholesterol both of which are associated with increased cardiovascular risk.

Short term side effects include increased facial hair, acne and local growth of darker hairs at the site of application. 

While the long-term health risks or benefits of testosterone are still unknown, and its impact on menopausal symptoms uncertain, it seems premature to consider testosterone therapy as a definitive solution to the multitude of woes it is proposed to help.