does l carnitine help burn fat Carnitine: the claims and why it may not work Losing weight with L-carnitine supplements.

Current clinical evidence primarily comes from observations where these death pathways are incidentally induced by conventional chemotherapies or targeted therapies

The inhibition of serine and glycine bidirectional conversion by sertraline prior irradiation reduces the pool of nucleotides, as we previously observed, and concurrent and post-treatment with sertraline might hinder the synthesis of the antioxidant GSH and NADPH production, which exposes cancer cells to the accumulation of endogenous ROS and radiation-induced ROS causing severe oxidative stress [70]

"The Effect of Aging, Nutrition, and Exercise during HIV Infection." HIV AIDS (Aukl) 2 (2010): 191-201

No, it is not considered a permanent side effect

You may need methylcobalamin if you are deficient in methyl-groups