Hair Loss / Thickening Shampoos (Tea tree oil)

“Hair-loss shampoos” are often marketed around reducing scalp inflammation and “blocking DHT,” so they commonly include ingredients that are anti-androgenic or anti–5-alpha-reductase in theory. The most common examples you’ll see in these formulas are things like ketoconazole, saw palmetto, pumpkin seed oil, nettle, reishi, green tea/EGCG, and sometimes caffeine—plus various “botanical DHT blockers.” Some of these have limited or mixed evidence for real-world DHT effects, but the marketing angle means many products still load them in, alongside soothing/antimicrobial additives.

For people with PFS/PSSD/PAS, the practical issue is that a “simple shampoo” can quietly contain anti-androgenic actives or hormonally relevant botanicals (and sometimes tea tree oil, which is often included for scalp antimicrobial effects and is occasionally discussed for hormone-receptor activity). Because sensitized individuals may flare from substances they previously tolerated, a cautious approach is to treat hair-loss shampoos as potential triggers: keep your routine minimal during stabilization, avoid “DHT blocker” blends if you’re reactive, and if you test one, change one thing at a time and stop if you notice a consistent worsening.

Crash Anecdotes:

https://www.reddit.com/r/FinasterideSyndrome/comments/1ce7bex/reaction_to_soapsshampoosadditives/

My Personal Risk Ranking:

Moderate Risk of Permanent Worsening (for PFS/PSSD/PAS):

If you currently have PFS/PSSD/PAS, these substances may carry a moderate risk of worsening symptoms—potentially in a lasting way—and is best avoided. Symptoms flaring is commonly reported.