From Mike Lustgarten:
Do you have to take Serine, or will Glycine work as well? Serine is metabolized into Glycine. Glycine also metabolizes homocysteine. Cysteine is needed as well. Hence GlyNAC reduces homocysteine.
This is why I dose both cysetine (through NAC) and glycine.
I’ve always tried to keep homocysteine low, since reading Dr. McKinney’s book on heart disease, now we find out centenarians have high homocysteine.
What to do?
I battled high homocysteine levels for quite a while and took a lot of b12 with only marginal benefit but adding NAC on top of b12 dropped mine down significantly.
NAC and glycine (or serine) metabolize homocysteine. However I thought serine had a metabolite that was carcinogenic which is why I use glycine instead.
Dr. Brad Stanfield did a video on this a while back.
This video does not give any good reason to think homocysteine will activate mTORC1. The data in it needs to be put into context to realize that.
In the study he’s using as a reason to think homocysteine increases mTORC1, it did indeed seem to activate it modestly, but this was seen in vitro at concentrations of 0.34 mM or higher. That’s about a thousand times higher than homocysteine levels in the blood of humans! So I would interpret this as indicating that it is very unlikely that homocysteine has any significant effects on mTORC1 levels in humans in vivo.