Scalp DHT vs Blood DHT: How Much Finasteride and Dutasteride Really Block
Finasteride cuts blood DHT by 70% but scalp DHT by far less. The biopsy studies behind the gap, what dutasteride adds, and why scalp DHT is what counts.
Category Hormones & Physiology
How hormones like DHT and testosterone drive hair loss, and what that means for treatment choices.
Thyroid, Hashimoto’s and Hair Loss: What the Evidence Supports
Thyroid disease causes hair loss and explains far fewer cases than people assume. The mechanism, the base rate, and how to tell it apart from pattern loss.
Anabolic Steroids and Hair Loss: Why Finasteride Often Cannot Help
Why finasteride cannot touch most anabolic steroids, which compounds bypass the enzyme entirely, and what the evidence says about losing hair on cycle.
Finasteride Dosage: Why 1 mg, and What Lower Doses Actually Do
The finasteride dose-response curve from the original trials: why DHT suppression plateaus below 1 mg, what 0.2 mg achieves, and the every-other-day question.
Post-Finasteride Syndrome: What the Evidence Actually Shows
What the evidence shows on post-finasteride syndrome: the blinded trial numbers, the nocebo experiment, and what is known about symptoms after stopping.
How to Keep Your Hair on TRT: A Practical Protocol
TRT can unmask male pattern hair loss by raising scalp DHT. Here is the mechanism, who is actually at risk, and a practical protocol to keep your hair on testosterone.
Saw Palmetto and Natural DHT Blockers: Do They Actually Work?
Saw palmetto inhibits 5-alpha-reductase in a test tube. In humans, the evidence is far thinner. Here is what the trials actually show, and what they don't.
RU58841 vs Finasteride for Hair Loss: What the Evidence Really Says
RU58841 blocks DHT locally at the follicle; finasteride cuts it systemically by 70%. Here is what the actual evidence shows and why one is a known quantity.
Dutasteride Long-Term Safety: What Years of Data Actually Say
By Philippe Boissard, hair-loss researcher and author. M.Sc., Aalborg University. Updated June 2026. I take dutasteride. Not finasteride, dutasteride, the stronger one. So when people ask me whether it’s safe for the long haul, I’m not answering as a neutral…
PP405: Is the “Baldness Cure” Real?
By Philippe Boissard, hair-loss researcher and author. M.Sc., Aalborg University. Updated June 2026. Every few years the internet decides the cure for baldness has arrived. Most times it’s vaporware. PP405 is different, and I say that as someone who’s professionally…