Anxiety. Evidence on the effects of 5-HTP for anxiety is unclear. Early research shows that taking 25-150 mg of 5-HTP by mouth daily along with carbidopa seems to reduce anxiety symptoms in people with anxiety disorders. However, other early research shows that taking higher doses of 5-HTP, 225 mg daily or more, seems to make anxiety worse. Also, taking 60 mg of 5-HTP daily through the vein does not reduce anxiety in people with panic disorders.
5-HTP is sometimes taken by people coming down from MDMA to relieve post-MDMA dysphoria.[8] As 5-HTP is a necessary precursor for the brain to produce more serotonin, and MDMA use depletes a person's natural serotonin levels, it is believed that taking 5-HTP after consuming MDMA will speed up serotonin production. DanceSafe claims that the anecdotal evidence is widespread and that the theory is physiologically reasonable.[9] Backing up this approach is research conducted by Wang, et al.  in 2007, which observed that MDMA-induced depletions of 5-HT (serotonin) were restored in rats after administration 5-HTP, and suggested that this approach might be clinically useful in abstinent MDMA users.[8]