The Truth About Glutathione Absorption
Glutathione is a naturally occurring tripeptide composed of three amino acids (cysteine, glutamic acid, and glycine) present in most mammalian cells, tissues and fluids. It is endogenously produced in the human body, critical to preserving cellular integrity, and essential for optimal health.
acts as an antioxidant, a free radical scavenger and a detoxifying agent, and is often referred to as “the master antioxidant.” Its health-supporting benefits are widely known by healthcare practitioners but the problem with glutathione has always been a question of bioavailability. The belief by many clinicians has been that oral glutathione is not absorbed systemically. After all, the size of the molecule alone would prevent it from being absorbed. But is that really the case? Research now reveals the truth about glutathione absorption.
“Clinical efforts to boost glutathione levels in the body have historically focused not on directly supplying glutathione but rather on increasing endogenous production by providing precursor molecules and cofactors,” according to Sarah Cook, ND, the author of a 2017 Natural Medicine Journal Research Guide on the topic of oral availability of glutathione. “Clinicians have taken a variety of approaches to circumvent the challenge of glutathione absorption…these approaches can be cumbersome, impractical, and inaccessible to many patients.”
Fortunately, clinicians no longer have to resort to nebulizers, transdermal creams, intravenous injections, or hoping their precursor protocol will work. Research now demonstrates that glutathione levels can be significantly increased by using specific forms of reduced glutathione in the tri-peptide form.
A landmark study involving supplementation was published in the European Journal of Nutrition. This long-term, randomized, placebo-controlled trial featured 54 healthy, non-smoking adults who received 250 mg or 1,000 mg of reduced glutathione daily for six months.
Glutathione levels were tested in whole blood, plasma, erythrocytes, lymphocytes, and exfoliated buccal mucosal cells at baseline and after one, three, and six months. At three and six months, glutathione levels increased significantly in whole blood and erythrocytes at both dosages. At the end of the study, 250 mg of glutathione increased levels in whole blood by 17% and in erythrocytes by 29%. At the 1,000 mg dose, whole blood glutathione levels were increased by 31%, 35% in erythrocytes and 250% in buccal cells.
“The research on absorbability thus far with Setria® is indisputable,” said Geo Espinosa, ND, LAc, when asked to comment on the study. “And it is backed by one of the most respected glutathione scientists in the country—John Richie, PhD, from Penn State University.”
We now know that defects in metabolic pathways required for endogenous glutathione synthesis may limit the efficacy of using precursor molecules and foods to boost glutathione levels. Results of the 2015 human clinical trial confirming absorption of oral glutathione now offers clinicians a new and effective approach to increasing glutathione levels.