Hormones & reproductive

Testosterone test: total, free and bioavailable

Testosterone drives energy, muscle, libido and mood in men and women.

Included in every $199 draw

Key benefits of testosterone testing

Measures total, free and bioavailable testosterone, not just one number.
Explains low energy, low libido, low mood or muscle loss.
Pairs with estradiol to show hormone balance.
Gives a baseline before any hormone or peptide therapy.
Tracks changes with sleep, weight and training.

What is testosterone?

Testosterone is a hormone made mainly in the testes in men and the ovaries and adrenal glands in women. Most of it is bound to proteins. The free and bioavailable forms are the parts your body can actually use.

Why testosterone matters

Low testosterone affects energy, muscle, bone density, mood and sexual health. In women, both low and high levels can cause symptoms, including irregular cycles and acne with PCOS.

What your testosterone results mean

Low: can cause fatigue, low libido, low mood and loss of muscle. It needs two morning tests to confirm.
In range: healthy hormone output for your age and sex.
High: in men, often linked to supplements or therapy. In women, it can point to PCOS.
Context matters: total testosterone can look normal while free testosterone is low.

Standard vs. optimal range

	Men	Women
Standard lab range (total)	About 264 to 916 ng/dL	About 2 to 45 ng/dL (varies by lab)
Insyght optimal range	Set by the Insyght medical team	Set by the Insyght medical team

LowHigh

Lab reference rangeYour optimal range

A value can read normal on a standard panel and still sit outside optimal. Insyght flags it.

Do I need a testosterone test?

Tired all the time, losing strength, or noticing a drop in drive? Testosterone is one of the first things to check, and free testosterone often tells the real story.

Get the full hormone picture

Insyght measures total, free and bioavailable testosterone plus estradiol and the T/E2 ratio in one draw. $199 a year.

Become a member See what we test

Similar biomarkers

EstradiolTestosterone/Estradiol RatioPSA (Men)DHEA-SCortisol

Frequently asked questions

What time should I test testosterone?

In the morning, ideally before 10 a.m. Levels are highest then and drop through the day.

What's the difference between total and free testosterone?

Total counts all testosterone in your blood. Free is the small unbound portion your tissues can use right away.

Should women test testosterone?

Yes. It affects energy, libido and bone health in women, and high levels can signal PCOS.

Medically reviewed by Dr. Maria Gutierrez Horn, MD, FACE, Board-certified endocrinologist, in practice since 2001. Last updated September 28, 2026.