Testosterone replacement is becoming popular for men. Cotsarelis warns that this may accelerate hair loss. Propecia might help -- but because it prevents testosterone breakdown, it might affect the dose of male hormone replacement therapy. Cotsarelis warns men taking both Propecia and testosterone replacement to make sure their doctor carefully monitors their testosterone levels.
In either sex, hair loss from androgenetic alopecia occurs because of a genetically determined shortening of anagen, a hair's growing phase, and a lengthening of the time between the shedding of a hair and the start of a new anagen phase. (See "Life cycle of a hair.") That means it takes longer for hair to start growing back after it is shed in the course of the normal growth cycle. The hair follicle itself also changes, shrinking and producing a shorter, thinner hair shaft — a process called "follicular miniaturization." As a result, thicker, pigmented, longer-lived "terminal" hairs are replaced by shorter, thinner, non-pigmented hairs called "vellus."
Thanks for the article with great info. I’ve been taking minoxidil 5% for the last 2 years. I’ve tried a generic minoxidil brand and also Kirkland to no effect. I’ve been hoping it’s maybe slowed the hair loss process. The hair around my crown just keeps getting thinner. Do you think changing to another “better quality” brand like Lipogaine or Rogaine could work? Or does it appear that any minoxidil brand is not going to work?