5-Alpha Reductase Inhibition
DHT conversion control for hair and prostate health.
TL;DR
5-alpha reductase converts testosterone into DHT, the androgen that drives male-pattern hair loss and prostate growth. Inhibiting it is a validated drug mechanism; supplement evidence is far weaker.
Why It Matters
DHT is roughly five times more potent than testosterone at the androgen receptor. Finasteride and dutasteride lower serum DHT by 70% and 90% respectively and are the reference standard. Botanicals marketed for this pathway (saw palmetto, pygeum, pumpkin seed oil) show small symptom effects with little consistent change in serum DHT.
How to Measure
Serum DHT by LC-MS/MS (immunoassays are unreliable at these concentrations), drawn in the morning alongside total and free testosterone. For prostate outcomes track IPSS symptom score, post-void residual and PSA; note that 5-ARI drugs halve PSA, so double the value when screening. For hair, standardized photography at fixed intervals beats subjective recall.
Biomarkers
Optimization Protocol
1. Confirm the goal — hair retention or urinary symptoms — because the evidence differs. 2. For meaningful DHT suppression, discuss finasteride or dutasteride with a clinician; no supplement matches them. 3. If pursuing botanicals, use standardized saw palmetto 320 mg/day of liposterolic extract for at least 12 weeks before judging. 4. Correct zinc deficiency if present; supraphysiologic zinc does not add benefit. 5. Track one objective metric (IPSS or photographs) rather than day-to-day impressions.
Lifestyle Levers
- •Maintain a healthy body weight
- •Resistance training
- •Limit alcohol
- •Adequate sleep
- •Avoid unnecessary anabolic steroid use
Supporting Supplements
Saw Palmetto
Saw palmetto may modestly ease urinary symptoms, but controlled trials show little consistent reduction in serum DHT.
Zinc
Zinc inhibits 5-alpha reductase in test tubes, but there is no human trial showing it lowers DHT or preserves hair.
Supporting Research
Frequently Asked Questions
Typical Timeframe
Serum DHT shifts within days on pharmacologic inhibitors; visible hair or prostate symptom change takes 3-6 months and up to 12 months for full effect.
Research Summary
My Notes
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This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.