JCI Sex, cells, and metabolism: Androgens temper Th17 mediated immunity L carnitine Tartrate in 1000 mg Capsules Hitting the Gym But Not Growing? The 'Secret Switch' Your Muscles Are Missing. NOW CARRYING! L Carnitine helps transport fatty acids to be burned as fuel inside the mitochondria. It also promotes healthy androgen receptors, healthy glucose metabolism, and heart health. We Androgen receptor density plays a meaningful role in muscle anabolism because it determines how strongly a muscle fiber responds to androgen signaling. Gabriel Alizaidy, MD, MS