On this page, we introduce the scientific research supporting D5 and NeuroReplete. This information provides the basics of how these formulations support normal serotonin and the catecholamines, which play a significant role in supporting normal brain, gut and overall health.
CHK Nutrition’s amino acid formulas provide normal balanced support of the following neurotransmitters:
- Serotonin – known to control mood, appetite, sleep, memory, learning, and temperature regulation.
- Dopamine, norepinephrine, and epinephrine (the catecholamines) – known to control movement, balance, motivation, and the drive for reward.
Why Administering Serotonin Or Catecholamines Is Not An Option
Serotonin and the catecholamines cannot be directly administered to support normal brain health because they are unable to cross the protective layer around the brain known as the blood-brain barrier. Thankfully, serotonin can be normally supported by 5-HTP. The catecholamines can be supported by L-tyrosine and L-dopa (naturally sourced from Mucuna).
Serotonin Pathway
The Catecholamines Pathway
Why does a shared enzyme matter to balanced amino acid administration?
A simple explanation is that administering 5-HTP at a ratio higher than recommended will reduce the access L-dopa has to the shared enzyme. L-dopa will not be able to convert into dopamine at the appropriate rate. The same is true if you administer tyrosine or L- dopa at a ratio higher than recommended. These precursors will crowd out 5-HTP, reducing its conversion into serotonin.
Eventually, the reduced conversion of the outnumbered group will result in the depletion of serotonin or dopamine, depending on which precursor is outnumbered. This depletion will have implications throughout the body. This depletion can occur from the administration of only serotonin precursors, only dopamine precursors, or an incorrectly balanced ratio of both.
This is why it is possible to do more harm than good by administering incorrectly balanced amino acid precursors
A Few Key Points: Serotonin and Catecholamine Support – Beyond Balance
Serotonin Support
- 5-HTP is the most direct way to support normal 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
For normal serotonin support, 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 administering additional 5-HTP.
Catecholamine Support
- L-tyrosine and L-dopa have an important role in providing normal support of the catecholamine system
- L-tyrosine and L-dopa cross the brain’s protective layer.
When supplementing with L-dopa, L-tyrosine supports normal L-dopa levels in the body without fluctuations. L-dopa is the intermediary molecule between L-tyrosine and dopamine. L-tyrosine’s ability to maintain normal L-dopa levels is essential for consistent catecholamine levels. Until recently, L-tyrosine’s importance was not well understood, making it an often overlooked nutrient for supporting catecholamine health.
L-dopa (naturally sourced from Mucuna) is more effective at supporting dopamine assuming that adequate levels of L-tyrosine are present. Therefore, many healthcare professionals choose to use L-tyrosine as a supporting base and increase Mucuna levels when they determine that addition dopamine support is beneficial.