Excess Hair Growth and Insulin: The Androgen Connection

Unwanted facial or body hair growth in women is distressing, commonly treated cosmetically, and frequently has a metabolic driver that goes unaddressed.

The chain

High insulin stimulates the ovaries to produce more androgens.

High insulin also lowers sex hormone binding globulin, the protein that keeps testosterone bound and inactive. Less binding means more free testosterone circulating.

Free androgens act on hair follicles, converting fine vellus hair to coarse terminal hair in androgen-sensitive areas — face, chest, abdomen, back.

So insulin sits two steps upstream of the symptom. That's why addressing insulin can affect it, and why treating only the hair leaves the driver running.

What it commonly accompanies

Hirsutism rarely appears alone. It usually travels with irregular or absent periods, acne, hair thinning at the scalp, and difficulty with weight — which together is the picture of PCOS.

If you have unwanted hair growth and irregular cycles, that combination is worth investigating rather than managing cosmetically.

What to ask for

Testosterone and sex hormone binding globulin, which together give the free androgen picture.

Fasting insulin or HOMA-IR, if your doctor will run them.

A discussion about PCOS, if cycles are irregular.

Thyroid function, since it affects hair in several ways.

Sudden, rapid onset of hair growth is a different situation and warrants prompt investigation rather than routine testing.

What actually helps

Improving insulin sensitivity. Protein-led meals, carbohydrate placed and paired, resistance training, sleep. This addresses the upstream driver.

Low glycemic eating specifically has trial evidence in PCOS — a twelve-month randomized trial found greater improvements in insulin sensitivity and menstrual regularity than a conventional healthy diet, independent of weight loss.

Medical options exist and work, including combined hormonal contraception and anti-androgen medications. These are legitimate and often used alongside dietary change rather than instead of it.

Cosmetic treatment is not a failure. Laser and electrolysis address what's already there, which dietary change won't reverse. Doing both is reasonable.

The expectation to hold

Hair follicles respond slowly. Existing terminal hair does not revert. What changes is the rate of new conversion, and that takes six months or more to become apparent.

Try this week: if you have this alongside irregular periods, ask about testosterone, SHBG and PCOS specifically.

Education, not medical advice.