I struggle to believe most people here have really tried the simple things like thyroid, vitamin D, calcium, sunlight, liver and oysters, reduce stress etc. The basic things can NOT be understated. For 2 whole years I didn't use thyroid supplementation, I barely ate liver/oysters, didn't have a great circadian rhythm/sunlight and more. Even just remembering to get in my daily 5000 steps(minimum). But as soon as I started focusing on these basic things, my hair is back to being so thick it's actually getting annoying. Posture and muscle tightness is also a big part. You should be able to comfortably get into a deep squat and work from the feet all the way up to the neck and scalp perimeter, stretching and taking care any tight muscles. Progesterone, adequate magnesium and vit k have helped a lot with this. And needless to say, without perfect gut health dont even think about regrowth, so the carrot salad is a must.