Glutathione

What it is

Glutathione is a tripeptide antioxidant the body makes from cysteine, glycine, and glutamate, and it is also sold as an oral supplement. It is marketed for antioxidant defense, detoxification support, and skin brightening. A major caveat is that orally taken glutathione is poorly absorbed and largely broken down in the gut before reaching the bloodstream.

Benefits

Standard oral glutathione (often 250-1,000 mg/day) has shown limited or inconsistent ability to raise systemic glutathione levels, and newer formulations were developed specifically to improve its poor absorption. Skin-lightening and antioxidant claims rest on small or short studies and should be viewed cautiously.

When to take it

Usually taken daily on an empty stomach; absorption remains a limiting factor regardless of timing. Studies showing any blood-level effect generally used weeks of consistent dosing.

Side effects

Generally well tolerated short term; oral use may cause mild bloating or gastrointestinal upset, and long-term safety data are limited. Caution is warranted with asthma and with chemotherapy drugs, where added antioxidants may theoretically interfere; intravenous use carries separate risks and is outside the scope of supplement dosing.

Sources

• A Targeted Metabolomic Assessment of Oral Glutathione Bioavailability and Safety in Humans: Randomized Crossover Trial (PMC)
• Augmented Glutathione Absorption from Oral Mucosa and Effect on Skin Pigmentation: A Clinical Review (PMC)

Products containing Glutathione

No products in our database contain this ingredient yet.