What percentage of men respond to topical minoxidil?

The answer to that reflects the presence of the enzyme sulfotransferase in significant quantities in the scalp.  “the follicular sulfotransferase activity of 120 pattern hair loss patients visiting a dermatology outpatient clinic in India. Overall, 40.8% of patients with pattern hair loss had low levels of sulfotransferase.  “Reference: https://pubmed.ncbi.nlm.nih.gov/30295395/