I'm in my fifties now but experienced major hair loss from my late 20's to my early forties. After a lot of research (supplements, OTC treatments, doctors, naturalpaths, articles) I came to realize that hairfall for most men and women comes from the afteraffects of Candida and leaky gut syndrome. Sugar of all types (even fruits) accelerates it. The candida/leaky gut comes from too many antibiotics and not enough Probiotics to clean up the mess that they leave and/or simply eating very poorly and causing bacteria proliferation in different pockets in the gut over a period of years.
Try this if you're losing hair in the shower- FAST for 24 -48 hours on water or broth. NO SUGAR. If your hairfall diminishes significantly or completely then your answer is there.