Again, it Doesn't matter the reason. If you don't supplement with 5-HTP AND tyrosine AND vitamin B6 which is a necessary co-factor AND vitamin C which is a necessary cofactor. You will have an imbalance of either serotonin or norepinephrine and dopamine because norepinephrine is synthesized from dopamine.Got it. I wasn’t saying, by the way, that one should supplement with 5htp all the time. I don’t think that is safe. I was only suggesting it as a way to restore serotonin after a roll when tryptophan hydroxylase has been depleted. However, I may change my mind about that based on your posts. So, thanks for the info.