What is 5 HTP? 5-HTP (5-Hydroxy L-Tryptophan) is a compound that the body makes from the amino acid tryptophan and is a precursor to the neurotransmitter serotonin. 5-HTP Benefits This provides 50mg of 5-HTP per capsule. Who is 5 HTP Suitable for? This is suitable for anyone taking part in intense bouts of high-intensity exercise. Please note that the labelling on this product is provided in English as a minimum. French, Italian, German, Spanish, Danish, Swedish and Finnish may also be present on a product by product basis.