l carnitine makes you weaker The Role of l-Carnitine in
Description
But one thing you can control is your diet

Clinical efficacy of combined L-carnitine and acetyl-L-carnitine on idiopathic asthenospermia

The third group was given a placebo (starch)

Baxmann AC, De OGMC, Heilberg IP

2009 Jan-Feb;32(1):35-40