Liposomal, reduced or S-acetyl glutathione: which one?

What is reduced glutathione?

Glutathione is a small molecule made of three amino acids: glutamic acid, cysteine and glycine. Your body makes it itself, inside its cells⁵. There it exists in two forms, reduced and oxidised. There’s more about the substance itself in our simple guide to glutathione.

Reduced glutathione, or GSH for short, is the form that does the work in the cell’s metabolism. It reacts with reactive oxygen species and, in doing so, turns into the oxidised form itself⁵. That’s why studies often also measure how much glutathione is present in each of the two forms². When a product label says ‘reduced glutathione’, it means the form the body itself uses.

Does glutathione actually reach the blood when you swallow it?

The answer depends on how long you look. In a 1992 study, seven healthy adults took about 3 g of glutathione in a single dose. Over the following four and a half hours, glutathione in their blood plasma didn’t rise noticeably. The researchers put this down to enzymes in the gut and liver breaking glutathione down¹.

A 2015 study, by contrast, looked at daily intake for six months. 54 adults took 250 or 1,000 mg of glutathione a day, or a placebo. With the higher amount, levels in red blood cells, blood plasma and lymphocytes were 30 to 35% higher after six months than at the start². One month after stopping, they were back to baseline².

There’s more on these studies in our article on glutathione absorption studies.

What is liposomal glutathione?

In liposomal glutathione, the glutathione is enclosed in liposomes, tiny vesicles made of phospholipids. Shells like these can protect their contents on the way through the digestive tract⁶. For a substance that enzymes in the gut and liver break down, that’s a sensible approach¹.

In a pilot study, 12 healthy adults took 500 or 1,000 mg of liposomal glutathione a day for one month. Levels had already risen after one week. After two weeks, they were up to 40% above baseline in whole blood, up to 25% in red blood cells and up to 28% in blood plasma³. The ratio of the oxidised to the reduced form fell by 20%³.

The study was small³. It also can’t be compared directly with the six-month study, because the duration, amounts and participants were different.

What is S-acetyl glutathione?

S-acetyl glutathione is glutathione with an acetyl group attached to its sulphur atom. The ‘S’ in the name is the chemical symbol for sulphur. The modified molecule is said to be more stable in the blood and to turn into glutathione only once it’s inside the cells⁴.

In one study, 18 healthy adults were given S-acetyl glutathione once and conventional glutathione once. After S-acetyl glutathione, both the peak level and the total amount of glutathione in plasma over time (the area under the curve) were higher. S-acetyl glutathione itself couldn’t be detected in the blood, so it’s apparently converted quickly. However, only a single dose was studied⁴.

Which form is right for you?

Liposomal and reduced aren’t mutually exclusive: a liposomal product can contain reduced glutathione, in which case it’s both. The studies described here looked at the forms in different ways, and none of them compared all three with each other.

• Regularity: in the six-month study, levels fell back to baseline within a month of stopping². So for blood levels that stay higher, what counts is taking it regularly.
• Format: liposomal glutathione comes as a liquid and in capsules, while glutathione without liposomes also comes as capsules or powder.
• Timing: for the right time of day, see our article on when to take glutathione.

If you’re pregnant, breastfeeding or taking any medicines, check with your doctor first. Do not exceed the recommended daily amount.

For our liposomal products at Melinava, we use phospholipids from European sunflowers.

Glutathione forms: frequently asked questions