Does creatine cause hair loss?
Current research gives no reason to avoid creatine on account of hair loss: both direct hair measurements and hormone levels remained unchanged. If you are experiencing hair loss, the cause is likely to be found elsewhere.
An RCT involving 38 young men showed that 5 grams of creatine per day for 12 weeks had no measurable effect on DHT (a hormone that can damage hair follicles) or on the ratio of DHT to testosterone, compared with a placebo. That is relevant because the idea behind the hair loss theory rested precisely on that supposed rise in DHT.
That same study also directly measured whether hair was in better or worse condition: hair follicle density, the number of hair units per cm², and cumulative hair thickness all remained unchanged. There was no statistically significant difference between the creatine and placebo groups on any of these outcomes.
Two separate international expert reviews, from 2021 and 2024, reached the same conclusion: there is no evidence that creatine supplementation causes hair loss or baldness. The DHT concern appears to trace back to one small study from 2009 that was never properly replicated and that only looked at DHT, not at hair itself.
The only creatine-related side-effect point mentioned in the available studies is an increase in creatine kinase (an enzyme found in muscles) that is sometimes measured. That has nothing to do with hair loss.
All claims are based on one RCT (n=38, PMID 40265319) and two narrative expert reviews (PMID 33557850 and 39720835). The RCT is small but directly targeted at the question. The baricitinib claims are outside the scope of the question and were not used.