Folic Acid is key to minimising hair loss. I’m ok so far taking 3 weeks of 10 mg MTX. The diagnosis of PMR and the accompanying weight loss and starting Prednisone in 2020 was when the hair thinning. In U.K. L’Oreal sell Serioxyl shampoo and conditioner which is wonderful and I take 4 capsules of Marine Collagen daily which is good for hair strengthening too. MTX has been miraculous so far. I believe illness, pain and inflammation cause the damage not the medicines - I’ll stand corrected!