Originally Posted by
Thomas59 
Am I correct in saying serotonin is produced in the gut ? I think I heard Fred Alan Wolfe or was it John Bergman say this .
I think around 90% of serotonin receptors are in the gut, and it is produced there by food containing the amino acid L-tryptophan. This is partially why people taking antidepressants have gastrointestinal side effects because the tablet is affecting the gut receptors there.