Testosterone

What Testosterone Measures

Women make more androgen than estrogen by quantity, and testosterone sits at the top of that family in potency.^[1] The related steroids DHEA-S, DHEA, and androstenedione circulate at higher concentrations, but they act mostly as pro-androgens: precursors the body converts into testosterone before they do their androgenic work. Of the whole group, only testosterone and dihydrotestosterone bind the androgen receptor directly.^[1]

Its supply is split. The ovaries secrete about a quarter, the adrenal glands about a quarter, and peripheral tissues make the remaining half by converting circulating androstenedione.^[1] In blood, most testosterone rides bound to SHBG (sex hormone-binding globulin) and albumin, so SHBG levels are a major determinant of how much stays free and biologically active.^[1] That split is why lab reports often carry two lines: total testosterone and free testosterone.

How It's Measured

Testosterone testing is usually a blood draw, and the most common version is a total testosterone test that counts both the bound and free portions. Free and bioavailable testosterone tests exist alongside it.^[2] Sensitive assays show a circadian rhythm with peak concentrations in the early morning hours, which is why labs often schedule the draw for the morning.^[1] Measuring it well isn't trivial either. The Endocrine Society published a position statement on the pitfalls of testosterone assays and called for standardized, validated normative values for total and free testosterone.^[6] Some at-home panels also report testosterone from saliva or urine samples.

Why People Track Testosterone

Testosterone usually appears as part of a broader hormone workup rather than a test on its own, sitting alongside estradiol, LH, FSH, SHBG, and DHEA-S on a panel. Clinical guidelines describe total and free testosterone as the standard first-line labs when clinicians assess androgens, including in PCOS workups.^[7] Reading that panel is the clinician's job, not the panel-holder's. What tracking adds is the record: a value on file, dated, next to the rest of your health data.

For how testosterone fits alongside the other hormones people test together, see At-Home Hormone Tests, Explained.

How Go Go Gaia Tracks Testosterone

Testosterone is a lab value, so it enters Go Go Gaia through lab upload. Add a lab report PDF or CSV in the web app and Gaia pulls out the values, storing total testosterone and free testosterone as separate analytes. It accepts salivary and urine testosterone results too. Each value lands on your timeline, charted over time next to your cycle data and everything else you log.

What the Research Shows

The honest headline on testosterone and the menstrual cycle is that studies disagree. A study that measured serum testosterone daily across whole cycles found concentrations were higher mid-cycle on average, but the rise was smaller than normal day-to-day variation and a peak wasn't discernible in every individual. The authors judged the mid-cycle elevation statistically significant but not clinically relevant.^[3]

Other studies land on each side of that line. One found no significant change in total or bioavailable testosterone between the early follicular and mid-luteal phases.^[4] Another, in healthy women, found total and free testosterone fluctuated significantly with a peak around ovulation, while also noting a wide range of values between individuals.^[5]

Put together: if a cycle-phase effect exists, it's modest, and it doesn't show up reliably from study to study or from person to person. That's a real finding, not a gap in the research.

Related Terms

Frequently Asked Questions

Educational information based on published sources. Not medical advice. For personal concerns, please consult your doctor.

Does testosterone change across the menstrual cycle?

The evidence is inconsistent. Some studies find a modest rise around ovulation, while others find no significant difference between cycle phases. A daily-measurement study found that the average mid-cycle rise was statistically significant but smaller than normal day-to-day variation, and not every woman showed a discernible peak.

What is the difference between total and free testosterone?

Total testosterone counts everything in the blood, including the large share bound to SHBG and albumin. Free testosterone counts only the small unbound fraction. Because SHBG levels vary between people, panels often report both values so the lab can describe the bound and unbound portions separately.

Why do labs often draw testosterone in the morning?

Testosterone follows a circadian rhythm, with sensitive assays showing peak concentrations in the early morning hours. Drawing at a consistent time of day makes results from different dates easier to compare, which is why many labs schedule the draw in the morning.