Lowering free testosterone comes down to two basic strategies: reducing how much your body produces and increasing the protein that binds testosterone so less of it circulates freely. The protein responsible for this binding is called SHBG (sex hormone-binding globulin), and it acts as a carrier that locks up testosterone in the bloodstream, preventing it from reaching tissues. Most effective approaches work through one or both of these pathways.
Free testosterone is the small fraction of total testosterone that isn’t bound to proteins and is therefore active in your body. For many women, especially those with PCOS, elevated free testosterone drives symptoms like acne, excess hair growth, and irregular periods. Here’s what actually works to bring those levels down.
Why Insulin Resistance Matters
If you have high free testosterone, insulin resistance is one of the first things to address. The connection is direct: when your cells stop responding normally to insulin, your body compensates by producing more of it. That excess insulin stimulates your ovaries to produce more androgens, including testosterone. At the same time, insulin resistance suppresses SHBG production in the liver, which means more of your testosterone stays unbound and active.
Research in the Journal of Clinical Endocrinology & Metabolism confirmed that insulin resistance is inversely related to SHBG levels. Fat accumulation in the liver is a key driver of this process, reducing expression of a transcription factor that the liver needs to manufacture SHBG. So the chain reaction looks like this: insulin resistance leads to lower SHBG, which leads to higher free testosterone, which leads to worse symptoms.
This is why weight loss, exercise, and dietary changes that improve insulin sensitivity can have outsized effects on free testosterone. Even modest reductions in body fat, particularly around the midsection, can increase SHBG and shift the balance.
Dietary Changes That Shift Hormone Levels
Switching to a lower-fat, higher-fiber diet has a measurable effect on circulating androgens. A study of 39 men who transitioned from a typical high-fat diet to an isocaloric (same total calories) low-fat, high-fiber diet for eight weeks saw a 12% reduction in circulating androgen levels, including significant decreases in both total and free testosterone. The effect came not from increased clearance of testosterone from the body but from reduced production.
Fiber plays a specific role here. It binds to steroid hormones in the gut during digestion, pulling them out of circulation through the digestive tract rather than allowing them to be reabsorbed. Increasing your intake of vegetables, legumes, whole grains, and fruits supports this process. There’s no single “magic number” for fiber intake, but most people fall well short of the 25 to 30 grams per day that’s generally recommended, so there’s usually room to improve.
You may have seen flaxseed recommended as a testosterone-lowering food. A study of healthy men supplementing with 13.5 grams of flaxseed per day found no significant change in total testosterone, free testosterone, or SHBG. The evidence for flaxseed specifically reducing androgens is weak, and you shouldn’t rely on it as a primary strategy.
Spearmint Tea
Spearmint tea has some clinical support, particularly for women with PCOS or hormonal imbalances. In a five-day study of 21 women with hormone imbalances, drinking two cups of spearmint tea daily decreased testosterone levels. A longer 30-day randomized trial of 42 women with PCOS found that those drinking spearmint tea twice a day had lower testosterone and higher levels of other reproductive hormones compared to a placebo group.
Two cups a day is the dose used in both studies. It’s a low-risk intervention, but the evidence base is still small, and the studies were short. Spearmint tea is reasonable as a complementary approach alongside other changes, not as a standalone treatment for significantly elevated levels.
Licorice Root
Licorice has a more specific mechanism: it blocks enzymes involved in testosterone production, including 17-hydroxysteroid dehydrogenase and 17-20 lyase. It also stimulates aromatase, an enzyme that converts testosterone into estrogen. In one study, women given 3.5 grams of a commercial licorice preparation daily (containing about 7.6% glycyrrhizic acid) saw measurable reductions in serum testosterone.
The catch is safety. Chronic consumption of high amounts of licorice can cause potassium levels to drop and blood pressure to rise, a condition called hypokalemic hypertension. This happens because a compound in licorice interferes with how your kidneys handle aldosterone, a hormone that regulates sodium and potassium balance. If you try licorice supplements, keep doses moderate and don’t use them long-term without monitoring.
Medications That Target Free Testosterone
Metformin
Metformin works on the insulin resistance pathway described above. By helping your cells respond to insulin normally again, it lowers circulating insulin levels, which in turn reduces ovarian androgen production and increases SHBG. The results can be substantial. In early clinical trials of women with PCOS taking metformin, free testosterone dropped by 49% and total testosterone by 52% over four to eight weeks. SHBG levels increased in parallel. These results held in both obese and lean women with PCOS, confirming that insulin resistance plays a role regardless of body weight.
Spironolactone
Spironolactone takes a different approach. It’s an androgen blocker, meaning it prevents testosterone from binding to receptors in tissues like skin and hair follicles. Common doses range from 50 to 100 mg, taken once or twice a day. Results take time: you may see improvement in acne after about three months, but it generally takes six months to see the full effect on other androgen-driven symptoms. Spironolactone is not safe during pregnancy because it can affect fetal development, so it’s typically prescribed alongside birth control.
Combined Oral Contraceptives
Birth control pills that contain both estrogen and a progestin raise SHBG levels, which directly reduces free testosterone. The estrogen component stimulates SHBG production in the liver, while certain progestins also have anti-androgenic properties. For many women with PCOS, oral contraceptives are a first-line treatment because they address multiple symptoms at once: regulating periods, reducing acne and hair growth, and lowering free testosterone.
Exercise and Body Composition
Regular exercise improves insulin sensitivity, which feeds into the SHBG pathway. Both aerobic exercise and resistance training help, though the effect is strongest when exercise leads to reductions in visceral fat (the fat stored around your organs). You don’t need extreme workout routines. Consistent moderate activity, something like 150 minutes of brisk walking or cycling per week, is enough to meaningfully shift insulin sensitivity over a few months.
Reducing body fat percentage matters more than the number on the scale. Someone who loses five pounds of visceral fat while gaining a few pounds of muscle may see better hormonal changes than someone who drops ten pounds through crash dieting, which can actually increase cortisol and disrupt hormone balance further.
How Long Before You See Changes
The timeline varies depending on the approach. Medications like metformin can produce measurable drops in free testosterone within four to eight weeks. Spironolactone takes longer, with visible symptom improvement at three to six months. Dietary and lifestyle changes generally need at least two to three months before they show up clearly on blood work.
If you’re tracking your levels, retesting too early can be misleading. A reasonable approach is to give any new intervention at least three months before repeating blood work, and to test in the morning when testosterone levels are most stable and consistent. For women with PCOS, measuring free testosterone or bioavailable testosterone is more informative than total testosterone alone, since total levels can appear normal even when free testosterone is elevated.