I’ve heard that large amounts of protein cause homocysteine levels to increase, which can cause various cardiovascular problems. My question is: Is the amino acid cysteine the thing that causes homocysteine levels to rise?
I’ve been thinking of taking some L-cysteine because I’ve heard that it is beneficial to muscle growth because of the sulfur contained in it. Can anyone elaborate on cysteine’s effects on muscle growth?

Homocyteine is a methionine metabolite that can be rendered harmless with adequate folic acid,B12,and B6 intake.L-cyteine oxidizes at such a rapid rate that it’s useless and possibly a pro-oxidant.N-acetylcysteine is a much more useful form,but it’s only a anti-oxidant not a muscle builder.

I can’t say I know absolutely for sure, but I don’t expect that taking cysteine would increase homocysteine levels. Homocysteine is made from
methionine and is used to make cysteine… not the other way around. It does not seem to me the reaction would run backwards significantly, giving homocysteine from cysteine. But I cannot say I have looked into it specifically other than happening to know the chemical reactions involved.

On the other hand, if you are eating a lot of protein, I would think you’re getting all the cysteine you could possibly use. If you want to try it, I don’t suppose it’s expensive… just be sure to do it where the only thing changing is the cysteine, if it seems like
it helped then you go off of it for a while
and then try again, rather than just staying on
it indefinitely. Sometimes it will seem like something helped the first time around, but then going off really did no harm, and going on the second time clearly does nothing, so you
have to follow this approach rather than just
concluding it works from the results of the
first usage. Good luck! (if you decide to try it)