First, don't take this if you're on medication targeting serotonin receptors, such as an ssri or snri. Assuming you're not on medication, the answer is, maybe, maybe not. The same answer you'd get if you went on medication. Sometimes things work, sometimes they don't. Second, 5-HTP isn't a vitamin -- it's an amino acid, a metabolite of L-tryptophan, which along with co-factors such as B6 (which is a vitamin) us used by the body to manufacture serotonin.