Pteridin-4 (BH4) (60 caps)


Pteridin-4 (BH4) (60 caps)

It is strongly recommended to select Overnight Shipping during warm weather and summer months.

This product ships with an ice pack, however it will arrive with the ice pack melted and the product at room temperature or warmer depending on your location. Refrigerate upon arrival. 

This product is not returnable or refundable for any reason.


Pteridin-4 contains important enzyme cofactors that are naturally present in a number of foods, including mammalian breast milk and royal jelly. 

Tetrahydrobiopterin was discovered to play a role as an enzymatic cofactor. The first enzyme found to use tetrahydrobiopterin is phenylalanine hydroxylase (PAH).

Tetrahydrobiopterin is biosynthesized from guanosine triphosphate (GTP) by three chemical reactions mediated by the enzymes GTP cyclohydrolase I (GTPCH),6-pyruvoyltetrahydropterin synthase (PTPS), and sepiapterin reductase (SR).


Tetrahydrobiopterin has the following responsibilities as a cofactor:


  • Tryptophan hydroxylase (TPH) for the conversion of L-tryptophan(TRP) to5-hydroxytryptophan (5-HTP)
  • Phenylalanine hydroxylase (PAH) for conversion of L-phenylalanine(PHE) to L-tyrosine (TYR)
  • Tyrosine hydroxylase (TH) for the conversion of L-tyrosine to L-DOPA(DOPA)
  • Nitric oxide synthase (NOS) for conversion of a guanidino nitrogen of L-arginine (L-Arg) to nitric oxide (NO)
  • Alkylglycerol monooxygenase (AGMO) for the conversion of 1-alkyl-sn-glycerol to 1-hydroxyalkyl-sn-glycerol


Suggested Dosage:  As a dietary supplement, take 1 capsule daily or as directed by your healthcare professional.

Refrigerate for maximal shelf life.

One capsule contains:


Supplement Facts
Serving Size 1 capsule %DV*
Servings per Container 60  
Vitamin C ( as ascorbic acid) 10 mg 17%
(a stable form of the physiologic agent, biopterin)
2.5 mg **

*Percent Daily Values are based on a 2,000 calorie diet. 
**Daily Value is not established

Other Ingredients: Sucros, gelatin, L-leucine.


This product is free of soy, yeast, gluten, and other common allergens. 

These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.