L Carnitine Tartrate Supplementation for 5 Weeks Improves Exercise Recovery in Men and Women: A Randomized, Double Blind, Placebo Controlled Trial L Carnitine Attenuates Testicular Dysfunction in Type 1 Diabetes Mellitus Via Modulation of Oxidative Stress, Inflammation, and miRNA Expression Inflammation Springer Nature Link 1 L Carnitine This amino acid plays a crucial role in fat metabolism and has been shown to support testosterone levels by improving androgen receptor activity. It also enhances muscle recovery and L Carnitine: Testosterone, Boost Energy & Performance 2025 Serum L Carnitine Levels Are Associated With First Stroke in Chinese Adults With Hypertension Stroke