DHT (dihydrotestosterone) is the hormone most responsible for male pattern hair loss and enlarged prostates, and there are several proven ways to lower it. Your body makes DHT when an enzyme called 5-alpha reductase converts testosterone at specific tissue sites like the scalp and prostate. Reducing DHT means either blocking that enzyme, limiting how much DHT reaches those tissues, or both.
How Your Body Makes DHT
Testosterone itself isn’t the main driver of hair loss or prostate growth. The real culprit is DHT, which forms when 5-alpha reductase strips a chemical bond from testosterone. This conversion happens locally in the tissues where DHT does its work, not throughout the entire body. There are multiple forms of this enzyme, but type 2 is the most biologically active and the primary target for treatment.
Understanding this conversion is useful because every effective DHT-reduction strategy targets some part of this process: blocking the enzyme, competing at the receptor, or reducing the raw materials available.
Prescription Medications
Pharmaceutical options are the most powerful way to lower DHT, and two drugs dominate this space.
Finasteride blocks the type 2 form of 5-alpha reductase. At the 1 mg daily dose used for hair loss, it reduces DHT levels in the blood by about 70% and within the prostate by up to 90%. A higher 5 mg dose is used for enlarged prostates. Because it only blocks one form of the enzyme, some DHT production continues through other pathways.
Dutasteride blocks both the type 1 and type 2 forms, producing a roughly 90% reduction in blood DHT levels. That extra suppression can translate to better results for some people, particularly those who don’t respond fully to finasteride. Dutasteride is primarily prescribed for enlarged prostates, though dermatologists sometimes use it off-label for hair loss.
Side Effects to Know About
Sexual side effects are the main concern with both drugs. Reviews of clinical data show finasteride is associated with erection difficulties in about 5 to 16% of users and reduced sex drive in 3 to 5%. However, long-term studies paint a more reassuring picture: drug-related sexual side effects occurred in less than 2% of men over several years, and the incidence dropped to 0.3% or lower by the fifth year. Importantly, the rate of men who actually stopped treatment because of sexual side effects was similar to those taking a placebo.
Topical Finasteride
If systemic side effects concern you, topical finasteride spray is a newer option. A phase III clinical trial found it improved hair count comparably to oral finasteride, but with dramatically lower drug levels in the blood (more than 100 times lower peak concentrations). It reduced blood DHT by about 34.5% compared to 55.6% for the oral version, meaning less of the drug reaches the rest of your body while still working locally on the scalp.
Natural 5-Alpha Reductase Inhibitors
Several natural compounds interfere with the same enzyme that prescription drugs target, though with less potency.
Saw palmetto is the most widely used herbal option. Its mechanism appears to work differently than originally assumed. Rather than simply blocking 5-alpha reductase, saw palmetto extract binds to multiple receptors in the lower urinary tract and can counteract testosterone-driven changes in prostate tissue. It also reduces testosterone-induced receptor changes in animal studies. Clinical evidence for measurable DHT reduction is limited, but many men with mild urinary symptoms use it as a first-line supplement.
Pumpkin seed oil has stronger clinical data behind it. In a randomized, double-blind, placebo-controlled trial, men with pattern hair loss who took 400 mg daily for 24 weeks saw a 40% increase in hair count, compared to 10% in the placebo group. That’s a statistically significant 30% net improvement. The dose was split into four 100 mg capsules, two before breakfast and two before dinner.
Green tea (EGCG) contains a polyphenol called epigallocatechin gallate that inhibits 5-alpha reductase in lab settings. The catch: it shows potent inhibition in isolated enzyme tests but not in whole-cell assays, which means the real-world effect of drinking green tea on your DHT levels is unclear. It may contribute as part of a broader dietary pattern rather than working as a standalone treatment.
Zinc and Vitamin B6
Zinc is one of the more compelling micronutrient options. Research published in the British Journal of Dermatology found that zinc at sufficient concentrations was a potent inhibitor of 5-alpha reductase activity in human skin, and at high concentrations it could completely shut the enzyme down. Vitamin B6 amplified zinc’s inhibitory effect, and when zinc, vitamin B6, and azelaic acid (a compound found in grains) were combined at very low doses that were ineffective individually, they achieved 90% inhibition of the enzyme.
This doesn’t mean taking a zinc supplement will replicate the DHT suppression of finasteride. These were concentrations applied directly to skin tissue in a lab. But ensuring you’re not zinc-deficient is a reasonable baseline step, especially since zinc deficiency is common in people with restricted diets. Foods high in zinc include oysters, red meat, pumpkin seeds, and lentils.
Ketoconazole Shampoo
Ketoconazole is an antifungal ingredient available in over-the-counter and prescription shampoos (commonly sold as Nizoral). Beyond treating dandruff, it inhibits 5-alpha reductase directly on the scalp. It also reduces scalp inflammation caused by a common fungus called Malassezia, which may independently contribute to hair thinning. Using a ketoconazole shampoo two to three times per week is a low-risk addition to any hair loss regimen, and many dermatologists recommend it alongside other treatments for that reason.
Combining Approaches
Most people serious about reducing DHT, particularly for hair loss, use a combination strategy rather than relying on a single method. A typical stack might include a prescription or topical DHT blocker as the foundation, ketoconazole shampoo for local scalp effects, and dietary support through zinc-rich foods or pumpkin seed oil supplementation. Each approach targets a slightly different part of the DHT pathway or works at a different site in the body, and the effects can be additive.
If you’re primarily concerned about prostate health rather than hair, the priorities shift. Saw palmetto and prescription 5-alpha reductase inhibitors have the most direct evidence for urinary symptom improvement. Pumpkin seed oil and ketoconazole shampoo are more relevant to scalp-specific DHT concerns.
The key tradeoff across all options is potency versus side effect risk. Dutasteride suppresses the most DHT but carries the highest likelihood of hormonal side effects. Topical finasteride and natural inhibitors offer gentler suppression with fewer systemic concerns. Choosing where you land on that spectrum depends on how aggressively you need to lower DHT and how you respond to initial treatment.