Androgens are hormones produced by the ovaries and adrenal glands, with the principal androgen being testosterone. In women, the ovaries directly release testosterone into the blood stream, but testosterone can also be made from other hormones that come from the ovaries and adrenal glands such as DHEA and androstenedione. In women and men, testosterone acts directly in cells, but it is also converted to estrogen, and has vital biological effects through estrogen action. [1.]
Testosterone blood levels in men are about 10-20 fold greater than in women and result in the male features we tend to associate with testosterone, such as deeper voice, more body hair, more muscle and so forth.
Testosterone blood levels in women tend to peak during their 20s. This is followed by a gradual decline with age. By the time a woman reaches menopause, blood testosterone levels are about one quarter of what they were at their peak. [2.] However, after the age of 65-70 years, women have testosterone blood levels similar to those seen in young women. [3.]
A sudden fall in testosterone blood levels occurs when women have both of their ovaries removed (surgical menopause). Other causes of low testosterone in women include:
- Use of the oral contraceptive pill - switches off testosterone production by the ovaries and produces a liver protein (SHBG) which may reduce the effects of testosterone;
- Oral steroid therapy - suppression of testosterone production by the adrenals;
- Anti-androgen therapy for acne, hirsutism or scalp hair loss - drugs that block the actions of testosterone in body cells; and
- Complete loss of pituitary function (panhypopituitarism).
To exclude other potential causes, we recommend you talk to your healthcare professional.
What are the consequences of low testosterone in women?
The effects of low testosterone in women have been greatly debated over many years. Firstly, and most importantly there is no blood level that can be used as a cut-off to “diagnose” low testosterone in women.
Some studies have indicated that there may be an association between low sexual desire and low testosterone, but this has not been a consistent finding in all studies. [4.]