Serotonin is useless guys.... Serotonin converts to melatonin in the brain and melatonin makes you calm/relaxed so its good for sleeping but just overall reducing stress... so just supplement with melatonin instead which will benefit you more and not come with any side effects you get from 5-htp if you do..Serotonin alone does not do much . If you have a good or even average diet you should be getting enough Serotonin anyway so just supplementing it with more is waste of time. You know how many things(FOOD) you take into your body contains tryptophan(serotonin another name) ? Too many.. unless you have a genetic mutation that breaks down serotonin fast or something you shouldnt be supplementing.. even then I dont think you should IMO serotonin = USELESS.
All the food that goes into your body the toxic/bad stuff in the gut gets converted to serotonin.
I'd agree with most of what you write.
But serotonin production can be low even though tryptophan from food is high.
This is because there's a second pathway for tryptophan utilization called the kyurenine pathway. It will ultimately produce NAD, but the products in between can also contribute to depression and anxiety. The pathway is activated by stress and broadly speaking inflammation and infection.
So 5-HTP can be helpful in some cases. I can't tolerate it orally even in tiny doses, so I switched to sublingual.
Also, melatonin production is inhibited by blue light, so 5-HTP supplementation doesn't automatically result in tiredness.