Yes, extensive studies have shown that taking muscle building protein supplements after workout can lead to increased hair loss. This happens because high intensity training such as strength training, cardio etc. increase amino acids in the muscles and this combined with the protein supplements increases the testosterone levels in the body, which in turn cause production of dihydrotestosterone (DHT). DHT leads to shrinking of hair follicles and eventually the hair growth cycle reduces to only 6-8 months. There are two major components namely casein and DHEA commonly found in protein supplements that are found to be major culprits in accelerated androgenetic alopecia.