Serotonin cannot be directly administered to enhance brain health because it is unable to cross the protective layer around the brain known as the blood brain barrier.  Thankfully, serotonin can be supported by 5-HTP, which crosses the brain’s protective layer and converts into this crucial neurotransmitter.

5-HTP is the most direct way to support serotonin.

  • 5-HTP crosses the blood brain barrier
  • 5-HTP is freely converted into serotonin without biochemical feedback inhibition
  • 5-HTP is more efficient at supporting serotonin than tryptophan

When it comes to supporting serotonin, some view both tryptophan and 5-HTP as viable nutrients for supporting serotonin.  However, 5-HTP is superior to tryptophan because tryptophan hydroxylase, which converts tryptophan into 5-HTP, is limited in terms of enzymatic activity.  Once tryptophan hydroxylase reached its threshold, additional tryptophan will not yield more 5-HTP. Therefore, tryptophan does not support serotonin as well as 5-HTP.

5-HTP is found in very trace amounts in a very small number of foods.  Therefore, 5-HTP supplementation is the most direct way of providing additional 5-HTP.


Peer-reviewed scientific studies testing CHK Nutrition’s amino acid formulas can be found in the following journals, as well as on PubMed and Dove Press websites:

  1. Neuropsychiatric Disease and Treatment” (Multiple Studies)
  2. “Book: Food and Nutrients in Disease Management”
  3. “Open Access Journal of Urology”(Multiple Studies)
  4. “Neuropsychiatric Disease and Treatment” (Multiple Studies)
  5. “Clinical and Experimental Gastroenterology”
  6. “International Journal of General Medicine” (Multiple Studies)
  7. “International Journal of Nephrology and Renovascular Disease”
  8. “Healthcare and Patient Safety”(Multiple Studies)
  9. “Clinical Pharmacology: Advances and Applications” (Multiple Studies)

Please note: These studies are intended to support structure-functions claims made regarding CHK Nutrition’s products. The studies may involve findings that discuss uses that go outside CHK Nutrition’s product labeling and product structure-function claims. This information is NOT presented to make drug claims about CHK Nutrition’s products. The intent of providing this information is to disseminate the scientific literature currently available about the CHK Nutrition products and the structure-function claims that we offer. Please read these studies to understand the strengths and limitations of the data.

Important: These statements have not been evaluated by the Food and Drug Administration (FDA). These products are not intended to diagnose, treat, cure, mitigate, or prevent any disease.


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