High testosterone usually traces back to one of a handful of causes, and the most common one depends on whether you’re male or female. In women, polycystic ovary syndrome (PCOS) accounts for the vast majority of cases. In men, the cause is more often linked to supplementation, body composition, or less commonly a tumor. Normal testosterone for adult men falls between 193 and 824 ng/dL, while for adult women the normal range is below 40 ng/dL. If your levels are above those ranges, something specific is driving them up.
How PCOS Drives Testosterone Up in Women
PCOS is by far the most common reason women end up with elevated testosterone. The mechanism centers on insulin. When your body becomes resistant to insulin, your pancreas pumps out more of it to compensate. That excess insulin doesn’t just affect blood sugar. It directly stimulates the ovaries to produce more testosterone. In lab studies, purified ovarian cells bathed in insulin significantly increased their testosterone output. Blood levels of insulin and testosterone show a striking 85% correlation, which strongly suggests one hormone is directly driving the other.
Insulin also lowers a protein called sex hormone-binding globulin (SHBG), which normally binds to testosterone and keeps it inactive in your bloodstream. So high insulin creates a double hit: your ovaries make more testosterone, and less of it gets neutralized by SHBG. The result is a higher level of “free” testosterone actively affecting your tissues. This is why women with PCOS who address insulin resistance through diet, exercise, or medication often see their testosterone levels drop without directly targeting the hormone itself.
Signs That Testosterone Is Too High
Elevated testosterone doesn’t always announce itself with obvious symptoms, especially if the increase is mild. But as levels climb, certain physical changes become hard to miss. In women, the most recognizable sign is hirsutism: coarse, dark hair growing in places like the face, chest, lower stomach, inner thighs, or back. Persistent acne that doesn’t respond to typical treatments is another common signal.
If testosterone stays elevated over time, more pronounced changes can develop. These include a deepening voice, thinning hair on the scalp, increased muscle mass, and decreased breast size. In men, abnormally high testosterone (usually from external sources like supplements or injections) can cause acne, mood changes, shrinking of the testicles, and a drop in sperm count as the body tries to compensate for the excess.
Adrenal Gland Problems
Your adrenal glands, which sit on top of your kidneys, also produce androgens. A condition called nonclassic congenital adrenal hyperplasia (CAH) is one of the underdiagnosed causes of high testosterone in women. It’s a genetic condition where the adrenal glands lack a specific enzyme needed to produce cortisol efficiently. The glands compensate by overproducing androgen precursors, which get converted into testosterone. Unlike classical CAH, which is detected at birth, the nonclassic form often doesn’t show up until puberty or early adulthood, when symptoms like irregular periods, acne, or excess hair growth appear.
Because the symptoms overlap so heavily with PCOS, nonclassic CAH is frequently misdiagnosed. A blood test measuring 17-hydroxyprogesterone can screen for it. If that level is borderline, a stimulation test using synthetic ACTH can confirm the diagnosis.
Supplements That Raise Testosterone
If you take DHEA supplements, they could be the culprit. DHEA is a precursor hormone that your body converts into testosterone. It’s sold over the counter and marketed for everything from anti-aging to fertility support, but it reliably raises testosterone levels. A large meta-analysis covering 42 publications found that DHEA supplementation increased testosterone by an average of about 28 ng/dL. At doses above 50 mg per day, the increase jumped to nearly 58 ng/dL.
The effect is actually more pronounced in women than in men (a roughly 31 ng/dL increase versus 21 ng/dL), which matters a lot given that the entire normal female range tops out at 40 ng/dL. A supplement that nudges a man’s levels slightly could push a woman well into abnormal territory. If you’ve been taking DHEA, testosterone boosters, or any “hormone support” supplement, that’s worth mentioning to your doctor before pursuing a more involved workup.
Tumors That Produce Androgens
Rarely, a tumor on the ovary or adrenal gland can pump out large amounts of testosterone. These are called androgen-secreting tumors, and they tend to cause rapid, dramatic changes rather than the slow progression seen with PCOS. A woman might notice her voice deepening or significant new hair growth over weeks or months rather than years.
Doctors suspect a tumor when testosterone levels are very high. In women, total testosterone above 200 ng/dL points toward an ovarian tumor. A marker called DHEAS, which reflects adrenal androgen production specifically, raises concern for an adrenal tumor when it exceeds 700 ng/dL. These tumors are rare, but the distinction matters because treatment is surgical removal rather than hormone management.
How High Testosterone Is Investigated
A single blood draw showing elevated total testosterone is just the starting point. To figure out why it’s high, doctors typically check several additional markers. DHEAS helps determine whether the excess is coming from the adrenal glands or the ovaries. A 17-hydroxyprogesterone level screens for nonclassic congenital adrenal hyperplasia. Prolactin is also tested because elevated prolactin (sometimes caused by a small pituitary tumor or thyroid problems) is associated with androgen excess.
In women with PCOS-range elevations, testosterone is usually mildly above normal. Values between the upper limit of normal and about 200 ng/dL are consistent with PCOS or other functional causes. When levels spike well beyond that, imaging of the ovaries or adrenal glands becomes important. Transvaginal ultrasound can reveal ovarian tumors, while CT or MRI scans can identify adrenal masses.
If there’s any question about whether the source is adrenal or ovarian, a suppression test can help sort it out. After taking a short course of a medication that temporarily quiets the adrenal glands, doctors recheck testosterone and DHEAS. If testosterone drops substantially, the adrenals were the source. If it stays elevated while adrenal markers fall, the ovaries are responsible.
The Role of Insulin and Body Weight
Insulin resistance doesn’t only affect women with a formal PCOS diagnosis. In men, research has shown that suppressing insulin levels leads to a drop in testosterone and an increase in SHBG, confirming that insulin plays a regulatory role in testosterone metabolism regardless of sex. Obesity amplifies this relationship because excess body fat promotes insulin resistance, which in turn can push testosterone production higher in women or alter its metabolism in men.
This connection explains why weight loss and improvements in insulin sensitivity often bring testosterone levels back toward normal without any direct hormone treatment. Even modest reductions in body fat can lower insulin enough to reduce the ovarian stimulus for testosterone production. For many women with mildly elevated testosterone and signs of insulin resistance, lifestyle changes targeting blood sugar regulation are the most effective first step.