Does l lysine cause weight gain?

My son was prescribed l-lysine by his doctor to help with his poor appetite and growth recovery after a major illness. He did put on some healthy weight, but that was because his normal appetite returned, not because of the supplement itself. Don't worry, it won't make you randomly fat.

I agree that lysine itself doesn't cause weight gain as it has no fat or sugar. Just make sure you are not overeating due to an increased appetite, which sometimes happens with lysine.

L-lysine is an essential amino acid which vegetarians sometimes lack, but taking it in high pill doses can mess with your digestion. It doesn't contain fat or high calories to cause actual weight gain. Better to get it naturally from dals, sprouts, and curd.

Oh god, I always worry so much about side effects before swallowing any supplement capsule! From what I know, lysine shouldn't cause weight gain, but the fear of it making us bloated is so real. Maybe check with your doctor once so you can sleep peacefully without worrying.