38 citations,
May 2000 in “Livestock production science” Giving high-quality protein or methionine supplements helps improve hair growth in Angora goats and, to a lesser extent, in Cashmere goats.
7 citations,
January 1982 in “Acta agriculturae Scandinavica” Mink use L-methionine and L-cystine slightly better than natural amino acids for hair growth, but D-methionine is not effective.
92 citations,
November 2003 in “The Journals of Gerontology” Testosterone supplements can increase muscle mass and strength in older men with low levels, but long-term effects and risks need more research.
72 citations,
October 1998 in “Baillière's clinical endocrinology and metabolism” Long-term testosterone therapy can cause hormone suppression, affect prostate and heart health, and alter physical characteristics, but does not increase prostate cancer risk and needs more research for full risk assessment.
31 citations,
January 2017 in “Advances in Experimental Medicine and Biology” Low testosterone and 5α-reductase inhibitors can harm men's metabolic and sexual health; testosterone therapy may help, but discussing 5α-RIs' side effects is important.