Facial hair in menopause: why it appears as head hair thins

The paradox explained

The most common question here is how hair can be disappearing from the head and appearing on the chin at the same time. The answer is that follicles in different body regions are programmed to respond to androgens in opposite ways.

Facial and body follicles respond to androgens by converting fine vellus hair into coarse, pigmented terminal hair. Scalp follicles in the androgen-sensitive pattern regions respond by doing the reverse, miniaturising over successive cycles until the hair is fine and short.

One hormonal signal, two opposite outcomes, which is why they arrive together.

Why the balance shifts

Testosterone in women falls gradually from the twenties onward and does not drop sharply at menopause. Estrogen does.

The result is not more androgen but less of what was counterbalancing it. Sex hormone binding globulin, which binds testosterone and keeps it inactive, also falls after menopause, leaving a greater proportion of testosterone free and biologically available.

So the change is relative and it is gradual, which fits the usual experience of noticing it over a year or two rather than suddenly.

When it needs investigating

Ordinary postmenopausal facial hair is gradual, limited to chin, upper lip and jawline, and unaccompanied by anything else. Departures from that deserve assessment:

• Rapid onset over weeks or a few months
• Marked growth, or growth on chest, back or abdomen in a male pattern
• A deepening voice, or enlargement of the clitoris
• Significant scalp hair loss at the temples in a male pattern
• New acne alongside it, particularly if severe
• Any of these accompanied by weight change or abdominal striae

What to rule out

Rapid virilisation raises the question of an androgen-producing tumour of the ovary or adrenal gland, which is rare but is the reason the pattern matters. Testing usually starts with testosterone and DHEAS.

Polycystic ovary syndrome is far more common and often becomes more apparent in midlife. Congenital adrenal hyperplasia in its milder form and Cushing's syndrome also present with unwanted hair growth. Some medications cause it, including certain steroids and, notably, minoxidil used for scalp hair.

When to see someone

Gradual chin and lip hair after menopause is expected and does not require investigation, though cosmetic treatment is a reasonable thing to want and to ask about.

See someone promptly for rapid growth, a male distribution, voice deepening or clitoral enlargement, and ask for testosterone and DHEAS specifically.