Hair Loss from Testosterone Replacement Therapy?

Dear Dr. Rassman,

I have been under the care of an anti-aging doctor for two years. I have been taking testosterone (TRT). I have had hair transplants 10 years ago. I have been recently experiencing
more hair in my comb. Can Testosterone replacement cause transplanted hair to be lost?

Testosterone replacement may cause androgenic alopecia, but it should not cause hair loss in the permanent hair that was transplanted from the back and sides of your head (these hairs are not affected by DHT). You may be experiencing hair loss from your native non-transplanted hair.