Writing in the journal Antioxidants, researchers from Canada and Australia noted that previous studies showed standard oral glutathione may not effectively raise levels in the body for healthy individuals.
“By nature, an orally ingested health supplement is only efficacious if it can adequately cross the blood–gut barrier and enter into the circulatory system; in other words, it is only efficacious if it is also bioavailable,” the researchers wrote. “Our findings support the premise that delivery-enhanced formulation features can influence oral glutathione exposure.”
The enhanced formulation, LipoMicel, contains micelles, which act as carriers for drug and supplement delivery.
Absorption challenges
Glutathione (GSH) is a water-soluble endogenous master antioxidant important for biological activity such as cellular defense, detoxification and has roles in several metabolic pathways in the human body. It is synthesized by the liver.
As people age, levels of GSH naturally decrease, leading to chronic disease, decreased mitochondrial health and higher levels of cellular damage and metabolic dysregulation. GSH deficiency has been linked to severe COVID-19 outcomes.
“Having garnered significant attention due to numerous positive health implications for the immune system, the cardiovascular system and the respiratory system, glutathione is being actively explored as an important antioxidant health supplement,” the researchers noted.
Intravenous delivery is efficient at getting glutathione into the body, but it may not be the most practical method for long-term use as compared to oral supplements. However, oral supplementation is not without disadvantages, including absorption challenges in the gastrointestinal system.
The aim of the pilot study was to compare three oral formulations—a novel micellar glutathione, standard glutathione and liposomal glutathione—using pharmacokinetic parameters to determine if the micellar formulation could at a lower dose deliver more GSH.
Study details
Researchers administered water and a standardized breakfast to fourteen participants each morning of the study. Participant blood was assessed for baseline concentrations of glutathione and associated metabolites.
Then they were given the following doses:
- Micellar glutathione (LipoMicel; Natural Factors, Burnaby, BC, Canada): contains 300 mg l-glutathione per soft-gel capsule.
- Liposomal glutathione (Setria; BioAbsorb Nutraceuticals, Richmond Hill, ON, Canada): contains 300 mg l-glutathione per soft-gel capsule.
- Standard glutathione (NOW Foods, Guelph, ON, Canada): contains 250 mg l-glutathione per hard-gel capsule, administered at a higher daily dose of 500 mg.
Blood samples were assessed 24 hours after doses were administered.
“In this randomized crossover study, the LipoMicel micellar formulation produced significantly higher baseline-adjusted systemic glutathione exposure than standard glutathione despite a lower administered dose,” the researchers explained. “Compared with standard glutathione (500 mg), LipoMicel at a lower dose (300 mg) increased iAUC and ΔCmax by ~2.49-fold and ~2.43-fold, respectively, and when dose-normalized (to a 300 mg equivalent), incremental systemic exposure and peak levels were up to ~4-fold higher, supporting greater absorption per unit dose.”
The findings indicate LipoMicel is a promising delivery method for oral glutathione, though the researchers added larger, long-term studies are still needed.
“From a practical perspective, the improved bioavailability observed with LipMicel may offer advantages in terms of dosing efficiency and patient compliance,” the researchers added. “Achieving greater systemic exposure with a lower administered dose can reduce pill burden and support sustained supplementation, thereby enhancing the feasibility of long-term use.”
Source: Antioxidants. doi: 10.3390/antiox15030354. “A Targeted Metabolomic Assessment of Oral Glutathione Bioavailability and Safety in Humans: A Randomized Crossover Clinical Trial.” Authors: Julia Solnier et al.
