MET-Rx carnitest 1000 helps boost receptors for testosterone and helps reduce exercise-induced muscle damage and soreness. MET-Rx carnitest 1000 is designed to help speed recovery by reducing exercise-induced muscle damage and soreness that are normal consequences of any serious bodybuilding program. The active ingredient in MET-RX carnitest 1000 was found in one University study to boost receptors for testosterone in weightlifters. MET-Rx utilizes the same L-carnitine L-tartrate which has been tested in several university trials.