Testosterone in Women: What It Does, Why It Rises and What Happens When It Falls

By Tina Chagoury, Clinical Dietitian · 7 min read · 2026-09-27

Testosterone is not only a male hormone. Here is what it does in women, why insulin and PCOS push it up, what happens when it falls after 40, and what helps.

Testosterone is called the male hormone, so many women are surprised when a doctor mentions it or a blood test flags it. Women make testosterone too, in much smaller amounts, and they need it.

The problems start when it runs too high, which is common in younger women with PCOS, or when it falls, which many women notice in their forties without knowing why. Here is what testosterone in women actually does, and what pushes it in either direction.

What testosterone does in a woman's body

In women, testosterone is made by the ovaries and the adrenal glands. It belongs to a group of hormones called androgens, which also includes DHEA and androstenedione.

It supports:

• Muscle and strength, and your ability to build and keep muscle
• Bone density
• Libido and sexual desire
• Energy, drive and motivation
• Mood and confidence
• Estrogen production. Your body converts part of its testosterone into estrogen.

Most testosterone in your blood is carried by a protein called SHBG. Only the unbound part, called free testosterone, is active. This matters because insulin and the contraceptive pill both change SHBG, and so change how much testosterone is actually working.

High testosterone in women: the signs

• Acne along the jaw and chin, often lasting into adulthood
• Unwanted hair on the face, chest or abdomen
• Thinning hair at the crown or temples
• Irregular or absent periods
• Difficulty conceiving
• Oily skin

I explain the skin side of this in Your Skin Is Reporting on Your Gut and Your Hormones.

What raises testosterone in women

PCOS is by far the most common cause. When ovulation is disrupted, androgens rise, and the familiar picture of irregular cycles, acne and unwanted hair follows. I walk through the full mechanism in What Is PCOS Actually Doing Inside Your Body?

Insulin is the part most women are never told about. High insulin tells the ovaries to make more testosterone. It also lowers SHBG, so more of that testosterone is free and active. This is why insulin resistance sits at the centre of so many cases of high androgens, and why blood sugar work tends to improve skin, hair and cycles together. Insulin Resistance in Women, Explained Simply covers this in detail.

Less common causes include an inherited adrenal condition called non classic congenital adrenal hyperplasia, Cushing's syndrome, some medicines, and supplements such as DHEA or products sold as testosterone boosters.

Rarely, a tumour of the ovary or adrenal gland produces androgens. The warning signs are rapid change over a few months, a deepening voice, fast increasing muscle bulk, very quick hair growth and enlargement of the clitoris. These need a doctor promptly.

What helps when testosterone is high

• Stabilise blood sugar. Protein at every meal, carbohydrate eaten with protein and fibre, and no all day grazing. This lowers insulin, which reduces testosterone production and lets SHBG rise.
• Build muscle. Strength training improves insulin sensitivity and is one of the most effective tools available for PCOS.
• Sleep and stress. Poor sleep and high cortisol worsen insulin resistance directly.
• Reduce the inflammatory load. Processed food, refined oils and constant sugar all feed insulin resistance.
• Weight, if it applies. For women carrying extra weight, even a modest loss often improves cycles and androgen levels.
• Zinc rich foods, such as meat, shellfish, pumpkin seeds and pulses. Zinc has a role in androgen metabolism.

Medical options exist for acne, hair growth and irregular cycles. Your doctor will match them to your situation and to whether you are planning a pregnancy.

Low testosterone in women

Testosterone declines gradually from your twenties onward. It does not drop suddenly at menopause the way estrogen does, unless the ovaries are removed surgically.

Other causes of low levels include the contraceptive pill, which raises SHBG and lowers free testosterone, undereating, overtraining, very low body fat, and some pituitary and adrenal conditions.

The signs women describe are low libido, low energy, losing strength or muscle despite training, and low motivation. These are real, but they are not specific. Iron deficiency, thyroid problems, poor sleep, low mood and relationship strain all produce the same picture, so they need checking first.

For postmenopausal women with persistently low desire that causes distress, some doctors prescribe testosterone in carefully monitored female doses. That is a medical decision made after assessment, not a product to buy online.

What you can control is muscle. Strength training is the most powerful thing you can do for strength, bone, metabolism and energy after 40, whatever your testosterone level. I explain why in After 35, Muscle Is the Most Valuable Thing You Can Build.

Why new chin hairs can appear in perimenopause

This part confuses many women. In perimenopause and after menopause, estrogen falls faster than testosterone does, so the balance between the two shifts. Some women notice coarse chin hairs or thinning at the crown for the first time in their late forties, even though their testosterone has not risen at all. What changed is the ratio, not the absolute level. Women with PCOS often find that their androgen symptoms change shape in this stage rather than disappear, and the metabolic side usually becomes more important.

How testosterone is tested in women

A useful panel includes total testosterone, SHBG, and either free testosterone or the free androgen index, plus DHEAS. Your doctor may add other tests depending on your symptoms, and timing within the cycle can matter, so follow their instructions.

Standard testosterone tests were designed around male levels and are less precise at the low levels women have. Borderline results should be read with care, and always together with your symptoms.

When to see a doctor

• Rapid hair growth, a deepening voice or other fast changes over a few months
• Periods that stop, or cycles that are consistently irregular
• Suspected PCOS
• Difficulty conceiving
• Before starting any testosterone, DHEA or other hormone product

This article is nutrition education, not medical advice. Hormone testing, PCOS diagnosis and any hormone treatment belong with your own doctor.

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About the author. Tina Chagoury is a licensed clinical dietitian specialising in women's hormonal health, inflammation and gut health, and the creator of the Hormone Reset Method™. Learn more about the Hormone Reset Method.

Frequently asked questions

Do women need testosterone?

Yes. In much smaller amounts than men, it supports muscle, bone, libido, energy and mood, and part of it is converted into estrogen.

What causes high testosterone in women?

PCOS is the most common cause, and high insulin is often what drives it. Less often it comes from adrenal conditions, medicines, supplements or, rarely, a tumour.

Does PCOS always mean high testosterone?

No. Some women with PCOS have high androgens on blood tests, others have signs such as acne or hair growth with normal results, and some have neither.

Can food lower testosterone in women?

Not directly. Food works through insulin. Stable blood sugar, enough protein and strength training lower insulin, which reduces testosterone production and raises SHBG.

Is low testosterone after 40 normal?

A gradual decline with age is normal. Sudden or severe symptoms, or a marked change after surgery, are worth discussing with your doctor.

Related reading

• What Is PCOS Actually Doing Inside Your Body?
• Insulin Resistance in Women, Explained Simply
• Hair Loss in Women: What It Is Usually Telling You