Introduction
Anyone who delves deeper into nutritional supplements will sooner or later come across two names: Glycine and NAC (N-Acetylcysteine). Both are amino acids – and both play an important role in human metabolism. It's no wonder, then, that they are increasingly being discussed together.
In this article, we will look at what glycine and NAC are, what functions they perform in the body, and why many people take them in combination.
What is Glycine?
Glycine is the smallest and simplest amino acid. The body can produce it itself (non-essential), but it is also taken in through food – primarily through collagen-rich foods such as bone broth, meat, and fish.
Glycine in the body:
- Building block for collagen (the most abundant protein in the human body)
- Involved in the synthesis of glutathione – an endogenous antioxidant
- Plays a role in energy metabolism and cell function
Note: There are currently no approved health claims for glycine according to EU Regulation (EC) No. 1924/2006. Food supplements are not a substitute for a balanced and varied diet and a healthy lifestyle.
What is NAC (N-Acetylcysteine)?
NAC is an acetylated form of the amino acid L-cysteine. It serves as a precursor for the body's synthesis of glutathione – one of the most important endogenous antioxidants.
NAC in the body:
- Provides cysteine as a building block for glutathione synthesis
- Is being intensively researched
- Occurs naturally in protein-rich foods (poultry, eggs, legumes)
Note: NAC is in a regulatory grey area in the EU. We recommend seeking medical advice before taking it.
Glycine + NAC: The Combination
Glycine and NAC are frequently discussed together because both act as precursors to glutathione. Glutathione consists of three amino acids: glutamate, cysteine, and glycine. NAC provides the cysteine.
This combination is being investigated in science under the term GlyNAC. Initial studies have examined the combination in older adults. However, the research is still in its early stages; larger clinical trials are pending.
What science currently shows (neutral):
- Glycine and cysteine ( from NAC) are natural components of the glutathione molecule
- Both amino acids are found in a normal diet
- The combination is actively being scientifically researched
How are Glycine and NAC taken?
Glycine is widely available as a dietary supplement and comes in powder or capsule form. NAC is also available as a supplement – however, before taking it, the current availability and legal situation in the respective EU country should be checked.
Typical dosages in studies were 1.8–2.4 g of glycine and 1.8–2.4 g of NAC daily. This does not constitute a dosage recommendation. We recommend seeking medical advice before taking any dietary supplements.
Conclusion
Glycine and NAC are two well-researched amino acids that play an important role in human metabolism. Their combination – known as GlyNAC – is the subject of current scientific investigations. The research is promising, but not yet complete.
Dietary supplements are no substitute for a balanced diet and a healthy lifestyle.
