Glutathione: the master antioxidant most people have never heard of
- , by SANUSq Research team
- 8 min reading time
It's the most abundant antioxidant working inside your cells — yet most people have never heard its name.
Meet your body's master antioxidant
Ask most people to name an antioxidant and they'll reach for vitamin C. Very few will say glutathione — even though, litre for litre, it's the most abundant antioxidant inside your cells. It works quietly, out of sight, in almost every tissue in the body.
Chemically, glutathione is small and elegant: a tripeptide built from just three amino acids — glutamate, cysteine and glycine. The clever part is the cysteine, which carries a sulfur-containing thiol group. That single thiol is the business end of the molecule, and it's what lets glutathione step in and neutralise reactive molecules that would otherwise damage cells.
Glutathione is the most abundant low-molecular-weight thiol made inside cells, with central roles in protecting them from oxidative damage and maintaining redox balance (Forman, Zhang & Rinna, 2009).
What glutathione actually does in the cell
Its primary job is redox balance. Cells constantly generate reactive oxygen species as a by-product of turning food and oxygen into energy. In sensible amounts these are normal; in excess they cause "oxidative stress". Glutathione acts as the cell's main buffer against that stress — so much so that the ratio between its active (reduced) and spent (oxidised) forms is widely used as a readout of how a cell is coping.
It does more than just mop up: glutathione is involved in the liver's conjugation reactions — the biochemistry that attaches glutathione to certain compounds so the body can process and clear them more readily. And, crucially, it helps regenerate other antioxidants, including vitamin C and vitamin E, returning them to their active form so they can work again. That recycling role is a big part of why it earns the "master antioxidant" nickname: it doesn't just act alone; it keeps the wider antioxidant network running.
Glutathione and vitamin C support one another within the body's antioxidant system, each helping to spare and regenerate the other (Meister, 1992). We'll return to that partnership in our next article.
What lowers your levels
The good news is that your body makes its own glutathione, synthesising it inside cells — with cysteine usually the limiting ingredient — and recycling it as it goes. The catch is that levels aren't fixed for life. Research suggests glutathione tends to decline with age, and that sustained oxidative demand can draw on reserves faster than the body replaces them.
Everyday factors commonly associated with a heavier antioxidant load include ageing, heavy alcohol intake, broken or insufficient sleep, and periods of illness. None of this is cause for alarm — it is simply why glutathione is worth understanding rather than taking for granted.
Tissue glutathione levels appear to fall with age even as the demands placed on the body's antioxidant defences rise (Maher, 2005).
The absorption puzzle
Here's where glutathione gets interesting — and where a lot of supplements fall short. Simply swallowing glutathione isn't as straightforward as it sounds. In an early study, a single oral dose failed to meaningfully raise blood glutathione in healthy volunteers because the molecule is largely broken apart by enzymes in the gut before it ever reaches the bloodstream.
The longer-term picture is more nuanced. A six-month trial found that daily supplementation did raise the body's glutathione stores over time — although levels drifted back towards baseline once people stopped. In other words, absorption is the real challenge, and how glutathione is delivered matters at least as much as how much is in the bottle.
That challenge is why delivery systems designed to shield glutathione as it passes through digestion — liposomal delivery among them — have been explored. One pilot study of oral liposomal glutathione reported increases in blood and immune-cell glutathione.
A single oral dose of glutathione did not significantly raise plasma levels in healthy volunteers (Witschi et al., 1992), whereas six months of daily oral supplementation increased body stores, which fell back after stopping (Richie et al., 2015). A small pilot of oral liposomal glutathione reported raised blood and immune-cell glutathione (Sinha et al., 2018).
For readers who like to explore the range, SANUSq offers a liposomal Glutathione (250 ml) and a Liposomal Glutathione bundle, as well as a liposomal Vitamin C with Glutathione — all formulated with this delivery challenge in mind.
Frequently asked questions
Does my body make its own glutathione?
Yes. Glutathione is synthesised inside your cells from three amino acids — glutamate, cysteine and glycine — with cysteine usually the ingredient in shortest supply. Your cells also recycle it, converting the spent form back to the active form so it can be reused.
Can I get enough glutathione from food?
Glutathione is present in some fresh foods, but dietary glutathione is largely broken down in the gut rather than absorbed intact, so food isn't a reliable way to raise your body's levels directly. Eating well still supports the raw materials and cofactors your cells use to make and recycle their own.
Why is glutathione hard to absorb from a supplement?
The molecule is vulnerable to enzymes in the digestive tract, which can break it down before it reaches the bloodstream. This is why the form and delivery of a glutathione supplement matter, and why approaches such as liposomal delivery — designed to protect the molecule through digestion — have been studied. The evidence here is still developing.
How is glutathione different from vitamin C?
Both are antioxidants, but they work in different places and as a team. Vitamin C is highly active in the watery spaces of the body, while glutathione does much of its work inside cells — and the two help regenerate each other. That partnership is the subject of our next article.
Is glutathione safe to take?
Glutathione has generally been well tolerated in the studies conducted to date. As with any supplement, it's sensible to speak with your healthcare professional before starting — particularly if you are pregnant, breastfeeding, or managing an existing condition.
See how it's made
We've explained why delivery matters — see how our liposomal Glutathione is made.
Read more on the blog
- Glutathione: the power of the master anti-oxidant
- Signs of glutathione deficiency: are you getting enough?
- What depletes glutathione in your body — and why you need it
Watch on YouTube
Top 5 Benefits of Liposomal Glutathione on our channel, @SANUSqHealthSupplements.
We wish you good health on your terms.
The team at SANUSq.
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The health information in this article is provided for educational purposes only. Consult your healthcare professional before making any medical decisions.
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