Back in the late ‘90s, the term “prohormone” took on a negative connotation when Mark McGwire revealed that he was using androstenedione, a prohormone supplement, while he was suspected of using steroids. McGwire never admitted to steroid use nor did he deny it, sparing himself the perjury fate of many of his peers. One of the fallouts of this was that prohormones fell into disfavor, forever associated with illegal steroid use.
But prohormones are supplemental and naturally occurring substances that provide the raw materials or precursors our bodies need to make crucial hormones. Many of these are necessary for health and functioning, and some are also beneficial for supporting muscle growth and secondary sex characteristics. Many legal products today contain prohormones that help boost testosterone, growth hormone and IGF-1, among other hormones. When your goal is to boost muscle mass through supplementation of legal prohormones, just make sure that they’re allowed by the athletic associations you compete within, and follow labeling directions for best result.