SLOT: Full Definition
What total and free testosterone measure
Total testosterone measures all testosterone in the bloodstream — both bound to carrier proteins like SHBG and the small fraction that is free. Free testosterone measures only the unbound, biologically active portion that can actually enter cells and exert effects. Both numbers are needed to understand androgen status accurately, especially in women, because Shbg strongly influences how much testosterone is actually doing the work.
At Modern Thyroid Clinic, testosterone testing is part of evaluating Low Testosterone Women, Polycystic Ovary Syndrome, unexplained low libido and fatigue, persistent acne or hair loss, and the perimenopausal and menopausal decline in androgens.
Why it matters
Testosterone is often labeled a 'male hormone,' but it is one of the most abundant biologically active hormones in women — produced by the ovaries, adrenal glands, and peripheral tissues. It supports:
- Libido and sexual response
- Energy, mood, and motivation
- Muscle mass and strength
- Bone density
- Cognitive function and confidence
Testosterone declines gradually from a woman's twenties onward, and ovarian production drops sharply at menopause and after surgical ovary removal. Excess testosterone — common in PCOS — produces a very different clinical picture: acne, scalp hair loss, unwanted body hair, and irregular cycles.
Reference range vs. functional/optimal range
Conventional reference range (adult women):
- Total testosterone: 8–60 ng/dL (varies by lab and age)
- Free testosterone: 0.3–1.9 pg/mL
Functional/optimal target: for symptomatic women, many clinicians aim for total testosterone in the upper third of the female reference range and free testosterone in the upper half — provided there are no androgen-excess symptoms. There is no consensus 'optimal' number; the goal is the lowest dose that resolves symptoms safely.
Total testosterone alone can be misleading. A woman with high SHBG (often from oral birth control or hyperthyroidism) can have normal total testosterone but very low free testosterone — and feel every bit of the deficiency.
What abnormal results suggest
Low free testosterone is common in women on oral contraceptives, after oophorectomy, in chronic stress states, and naturally with aging — particularly through perimenopause and menopause. Symptoms include low libido, fatigue, low motivation, loss of muscle tone, and depression that does not respond to standard treatment.
High free testosterone is most often seen in Polycystic Ovary Syndrome, where insulin resistance drives ovarian androgen excess. It can also occur with adrenal hyperplasia, certain tumors (rare), or exogenous testosterone use. Symptoms include cystic acne, scalp thinning with frontal recession, unwanted facial or body hair, and irregular periods.
Testosterone is most accurately interpreted alongside SHBG, DHEA-S, Fasting Insulin, and full thyroid labs. Treatment — when indicated — should always be guided by a clinician trained in women's hormone therapy, because dosing and monitoring are very different from male testosterone protocols.
Common symptoms
Common questions
Why is my total testosterone normal but I still have symptoms?
This is one of the most common patterns we see. Total testosterone can sit in the middle of the lab range while free testosterone — the active fraction — is at the bottom or below it, usually because SHBG is high. Common causes of high SHBG include oral birth control, oral hormone replacement, hyperthyroidism, and undereating. Symptoms of low free testosterone (low libido, fatigue, low motivation, brain fog) can be just as severe in this pattern as in women with low total testosterone. The fix is to address the SHBG driver, not just look at the total number.
Should I take testosterone in menopause?
Testosterone therapy in women is supported by growing evidence for low libido (hypoactive sexual desire disorder) and may help with energy, mood, and muscle in selected women. It is not FDA-approved for women in the U.S., so prescriptions are off-label and require a knowledgeable clinician. Dosing is roughly one-tenth of male doses. With proper supervision, monitoring, and clear goals, testosterone can be a meaningful part of menopausal care for the right candidate. It is not a first-line therapy for everyone, and it is not appropriate without proper evaluation and follow-up.
Can high testosterone be lowered without medication?
Often yes, especially when the cause is PCOS or insulin resistance. The most effective lever is treating the underlying insulin resistance through nutrition, strength training, sleep, and sometimes medication like inositol or metformin. As insulin falls, SHBG rises, and free testosterone often comes down — taking acne, hair loss, and cycle irregularity with it. Stress reduction, adequate protein, and treating concurrent thyroid issues also help. Cosmetic anti-androgen medications are a separate question and can be discussed when lifestyle work isn't enough.
Think you might be dealing with this?
Talk to a Modern Thyroid Clinic specialist about your symptoms, labs, and next steps.
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