Doctor's Best® 5-HTP Enhanced with Vitamins B6 and C is enhanced with vitamins B6 and C to help maintain mental and emotional well-being. 5-HTP (or 5-hydroxy L-tryptophan) is a naturally occurring metabolite of the amino acid tryptophan. It is converted in the brain to serotonin, a neurotransmitter substance found at the synapses between neurons. 5-HTP helps maintain healthy sleep patterns and support overall mental health and wellness.