L-g is an amino acid, , it is an essential, so your body normally will make enough, , but if you are working out aggressively you may need a boost, , i would talk with a trainer or a dietician before starting on it, mostly because if you stop using it you may have some issues, , there are people that get caught up in excessive vitamin use, which is just as bad as too little vitamin use, , our bodies will make use of the vitamins we take in thru food intake, , always check it out with the people that can guide you to remain safe, , , , , , , only my thoughts, not challenging anyone, but there are so many scams out there, , , just be safe,