Sharma · Dermatologic therapy 2019 · Uncontrolled prospective pre-post study · n=?

Tretinoin enhances minoxidil response in androgenetic alopecia patients by upregulating follicular sulfotransferase enzymes.

Cited 36 times in the scientific literature.

Level 4 - case-series / case-control

Uncontrolled prospective before-and-after cohort assessing an enzymatic biomarker response.

PubMed 30974011 · doi:10.1111/dth.12915 · record verified 2026-08-29

What was done

Researchers evaluated the effect of 5 days of topical tretinoin application on follicular sulfotransferase enzyme expression in hair follicles of subjects with androgenetic alopecia to determine if it altered predicted minoxidil response status.

What was found

Following 5 days of topical tretinoin application, 43% of subjects initially predicted to be nonresponders to minoxidil converted to predicted responders through upregulation of follicular sulfotransferase. The abstract reports no total sample size, absolute enzyme measurements, or confidence intervals.

Why it matters

This study provides a biochemical mechanism (sulfotransferase upregulation rather than altered skin permeation) explaining how topical retinoids may improve minoxidil response rates in nonresponders.

Limits

The abstract omits sample size, participant demographics, and statistical significance measures. The study was uncontrolled, evaluated only a 5-day exposure, and measured a surrogate enzymatic predictor rather than actual clinical hair growth outcomes.

Cited by