(6R)-Tetrahydro-L-biopterin-15N3,13C1 Triflate is the isotope labelled analog of (6R)-Tetrahydro-L-biopterin (T293175, Sulfate Salt); a natural cofactor for phenylalanine hydroxylase, tyrosine hydroxylase, tryptophan hydroxylase, and nitric oxide synthase. Also an essential cofactor for the production of neurotransmitters such as catecholamines, serotonin, and nitric oxide. Increasing BH4 levels boosts sensivity to pain.