Glutathione is a tripeptide composed of glutamine, cysteine, and glycine, and serves as a major intracellular antioxidant. Its use in the context of heavy metal poisoning is supported by scientific literature, particularly due to its role in cellular detoxification processes. Glutathione can bind to heavy metals such as mercury, lead, and cadmium through its thiol group, forming complexes that are more easily excreted by the body. This process is known as glutathione conjugation and is facilitated by enzymes such as glutathione S-transferases (GSTs).

Several in vitro and animal studies have demonstrated that increasing glutathione levels can enhance the excretion of heavy metals and reduce their toxic effects on cells and tissues. For example, research has shown that glutathione supplementation or precursor administration (e.g., N-acetylcysteine) can mitigate oxidative damage and organ dysfunction associated with heavy metal exposure. In clinical practice, glutathione is sometimes used alongside chelation therapies, though robust, large-scale human trials are limited.

While the mechanistic rationale and preclinical evidence are strong, direct clinical evidence in humans is less abundant, and most guidelines still prioritize standard chelation agents. Nevertheless, glutathione's use is scientifically grounded, especially as an adjunct to other therapies. The evidence rating reflects promising but not definitive support for its use in heavy metal detoxification.