Tapinarof Cream for Atopic Dermatitis: Pharmacokinetics, Systemic Exposure, and Preliminary Efficacy/Safety Results

Topical finasteride concentrations are likely much higher than necessary for effective follicular DHT suppression, with current standards being 100-1000 times above the theoretical minimum. Lower concentrations (0.001-0.0025%) might still work locally while minimizing systemic exposure.

Topical finasteride may have higher systemic absorption and lower efficacy when using a Propylene Glycol/Ethanol formulation compared to the hydroxypropyl chitosan (HPCH) formulation. The safety profile of topical finasteride relies heavily on the HPCH formulation, and using standard solutions might lead to different pharmacokinetics.

Topical finasteride results in plasma levels 100 times lower than oral finasteride, potentially reducing systemic side effects. Users report similar efficacy with fewer side effects, suggesting a preference for topical application.

The conversation discusses using very low dose topical finasteride to achieve specific serum DHT reduction percentages. It concludes that finasteride dosage increases linearly between 5-30% DHT reduction but requires exponential increases for reductions up to 70%.

Topical dutasteride may have limited absorption due to its higher molecular mass compared to finasteride, potentially affecting its efficacy in suppressing DHT locally. Microneedling might enhance dutasteride absorption, possibly offering stronger local DHT suppression with fewer systemic effects.

Topical finasteride (P-3074) can inhibit scalp DHT by up to 70%, with some users experiencing systemic absorption similar to oral use. Users discuss varying application frequencies and concentrations, with some noticing side effects when overused.