Several things lower DHT, ranging from prescription medications that cut levels by 70% to 95%, to supplements and foods that block the enzyme responsible for producing it. DHT (dihydrotestosterone) is a potent form of testosterone that drives hair loss and prostate growth, so most people searching for ways to reduce it want to address one of those two problems. Here’s what actually works, what shows promise, and what to be realistic about.
How Your Body Makes DHT
Your body converts testosterone into DHT using an enzyme called 5-alpha reductase. This enzyme exists in two forms, and they’re active in different tissues: the scalp, skin, prostate, and liver. Anything that slows down or blocks 5-alpha reductase will reduce DHT production. That’s the central mechanism behind nearly every DHT-lowering strategy, whether it’s a prescription drug or a plant extract.
Prescription DHT Blockers
The most effective way to lower DHT is with prescription 5-alpha reductase inhibitors. Two drugs dominate this category, and they differ significantly in potency.
Finasteride blocks one of the two forms of 5-alpha reductase and reduces blood DHT levels by about 70%. It’s the most commonly prescribed option for hair loss. Dutasteride blocks both forms of the enzyme and suppresses blood DHT by roughly 93 to 95%. In a head-to-head dose-ranging trial, dutasteride at its standard dose achieved a mean DHT reduction of 94.7%, compared to 70.8% for finasteride, a statistically significant difference. That gap in potency is consistent across studies lasting up to four years.
Dutasteride is primarily prescribed for enlarged prostate rather than hair loss, though some doctors use it off-label for that purpose. Both medications require ongoing use to maintain their effect. Once you stop taking them, DHT levels return to baseline within weeks to months.
Saw Palmetto
Saw palmetto is the most studied natural DHT blocker. It works as a competitive inhibitor of both forms of 5-alpha reductase, the same enzyme targeted by prescription drugs. But it does more than just block DHT production. It also reduces DHT’s ability to bind to androgen receptors by nearly 50% and increases the activity of another enzyme that converts DHT into a weaker, less active hormone.
Clinical results are modest but real. Across multiple randomized trials, saw palmetto supplements have shown a 60% improvement in overall hair quality compared to 11% in placebo groups. One study found that 83.3% of participants using saw palmetto saw increased hair density, and 52% had their hair loss stabilized. A topical saw palmetto lotion produced a 27% improvement in total hair count over 50 weeks, compared to about 14% for the vehicle alone. Hair thickness improved by about 30% over the same period.
These numbers are encouraging but nowhere near what prescription drugs deliver. Saw palmetto is a reasonable option if you want a gentler approach or can’t tolerate medication side effects.
Pumpkin Seed Oil
Pumpkin seed oil contains compounds that appear to inhibit 5-alpha reductase, though the research is still catching up. A 2021 study found that applying pumpkin seed oil topically for three months helped prevent female pattern hair loss and promoted new growth. Animal studies support these findings, but large-scale human trials haven’t been completed yet. Some people take pumpkin seed oil capsules (typically 400 mg daily), though the optimal dose and route, whether oral or topical, remain unclear.
Green Tea
Green tea contains a polyphenol called EGCG that shows potent 5-alpha reductase inhibition in laboratory settings. In cell-free assays, EGCG effectively blocks the enzyme. The catch is that this effect hasn’t been confirmed in whole-cell assays or definitively in living humans. Animal studies are suggestive: rats given EGCG had lower testosterone levels and smaller prostates than controls. But whether drinking green tea translates to meaningful DHT reduction in your body is still an open question. It likely contributes a small effect as part of a broader strategy rather than serving as a standalone solution.
Rosemary Oil
Rosemary oil doesn’t lower DHT directly in any confirmed way, but it shows up in nearly every DHT-related search because it fights hair loss through other mechanisms, primarily by improving scalp blood flow. In a six-month randomized trial comparing rosemary oil to 2% minoxidil in 100 patients with pattern hair loss, both groups experienced a significant increase in hair count by the six-month mark, with no significant difference between them. Neither group saw improvement at three months, so patience matters. Rosemary oil may complement a DHT-lowering strategy even though it works through a different pathway.
Lycopene and Tomato-Rich Foods
Lycopene, the red pigment in tomatoes, watermelon, and pink grapefruit, interferes with DHT signaling at the cellular level. Rather than blocking DHT production, lycopene reduces what DHT can do once it’s made. In prostate cells, lycopene decreased the movement of androgen receptors (the docking stations DHT uses) into the cell nucleus by about 60%, and reduced a key co-activator protein by about 50%. This effectively blunted DHT’s ability to stimulate cell growth.
These findings come from laboratory studies using dietary concentrations of lycopene, meaning amounts you could plausibly get from food. Cooking tomatoes in oil increases lycopene absorption significantly. While this research is most relevant to prostate health, it suggests that lycopene-rich foods can meaningfully dampen DHT activity in tissues.
Exercise and DHT
Exercise affects DHT levels, but not in the direction most people hope. High-intensity aerobic exercise causes a rapid spike in blood DHT levels immediately after the session. Levels return to baseline within about 60 minutes of recovery. Submaximal exercise raises testosterone but doesn’t produce the same DHT spike. Resistance training similarly raises testosterone acutely, with variable effects on DHT conversion.
This doesn’t mean exercise worsens hair loss or prostate issues. The spikes are temporary, and the overall metabolic benefits of regular exercise, including better insulin sensitivity and lower body fat, likely outweigh any brief hormonal fluctuations. But if you’ve seen claims that exercise “naturally lowers DHT,” the evidence actually points the other direction for intense workouts.
Why Lowering DHT Too Much Is a Problem
DHT isn’t purely harmful. It plays important roles in male development, sexual function, and body composition. The effects of very low DHT are most clearly seen in people born with 5-alpha reductase deficiency: underdeveloped genitalia, absent or minimal facial hair growth, and a small or absent prostate. In adults using DHT-blocking medications, some experience reduced libido, erectile difficulty, or changes in mood and energy. These side effects are well-documented with prescription inhibitors and typically resolve after stopping the medication, though a small percentage of users report persistent symptoms.
This is the core tradeoff. Aggressive DHT suppression (93% or more with dutasteride) is more effective for hair retention and prostate shrinkage but carries a higher risk of hormonal side effects than moderate suppression. Milder approaches like saw palmetto and dietary strategies produce subtler results but are far less likely to cause problems. Many people find a middle path works best: a moderate pharmaceutical dose combined with natural strategies, or starting with supplements before escalating to medication.