@Judee
@ljimbo423 's explanation re ATP is excellent (thanks, Jim!) and here's a study that explains the competition w tryptophan ...
"The rate-limiting step in the synthesis of 5-HT is the transport of tryptophan across the blood-brain barrier. This transport is influenced by the fraction of tryptophan available for transport into the brain and the concentration of the other large neutral amino acids, including the BCAAs (leucine, isoleucine, and valine),
which are transported via the same carrier system. Studies in human subjects have shown that the plasma ratio of free tryptophan (unbound to albumin)/BCAAs increases and that tryptophan is taken up by the brain during endurance exercise, suggesting that this may increase the synthesis of 5-HT in the brain. Ingestion of BCAAs increases their concentration in plasma. This may reduce the uptake of tryptophan by the brain and also 5-HT synthesis and thereby delay fatigue."
https://pubmed.ncbi.nlm.nih.gov/16424144/
Maybe the key is to eat some turkey (for the tryptophan) while trialing BCAAs so you don't go too low on tryptophan?? and, of course, start w a lower BCAA dose...
I'm finding that any time I screw around w neurotransmitters, it makes me sick... I just tried ALCAR, and it didn't work for me... My focus lately has been on increasing immunity, and trialing some mito/ATP supplements.. Some of the mito supplements work, but they do other things, so maybe it's a coincidence... I have a REALLY hard time w oxidative stress (any kind of particulate matter.. pollution, dust, pollen... but no IGE allergies, they trigger a mast cell reaction)
The things that I take that are also beneficial for ATP/mito: ALA, omegas, magnesium citrate, and I've been taking and liking Ribose lately..... I felt completely NORMAL on Monday, thanks to Ribose (and maybe partly due to andrographis), but who know if it can be sustained..