Glutathione rises fastest and highest in the blood when it bypasses the digestive tract. After an intravenous infusion in healthy volunteers the plasma level jumped from 17.5 to 823 µmol/l, almost 50 times. An ordinary capsule as a single dose did not raise it at all, and with 1,000 mg swallowed daily the level rose by 30 to 35 percent only after half a year. Liposomal glutathione gave a rise of 40 percent after two weeks in a small study. If you are choosing a form of glutathione, below are the numbers from studies for each of them.
Why does the form of glutathione matter?
Glutathione is a tripeptide, a chain of three amino acids: cysteine, glycine and glutamic acid. When swallowed, glutathione is cut into pieces before it reaches the blood. A 1992 study in the European Journal of Clinical Pharmacology points to the enzyme gamma-glutamyl transferase in the gut and liver, which breaks down glutathione from food.
This is why not only the dose matters, but also the route into the blood. An injection bypasses digestion completely, a liposome encloses glutathione in a fatty shell, and an ordinary capsule passes through digestion without protection. All routes of peptide administration are compared in the guide on peptide routes of administration.
What did studies of glutathione capsules show?
Results for the ordinary capsule depend on how long it is taken. Short studies showed no change, and only a six-month placebo-controlled study showed a clear rise.
| Study | Dose and duration | Glutathione in the blood |
|---|---|---|
| Witschi, 1992, 7 people | a single dose of about 3 g | no significant rise over 270 minutes |
| Allen and Bradley, 2011, 40 people | 500 mg twice a day, 4 weeks | no change |
| Richie, 2015, 54 people | 250 mg a day, 6 months | plus 17 percent in blood, plus 29 percent in red blood cells |
| Richie, 2015, 54 people | 1,000 mg a day, 6 months | plus 30 to 35 percent in red blood cells, plasma and lymphocytes |
In the 2015 study the level rose after one month and then further after three and six months. The activity of NK cells, the natural killers of the immune system, more than doubled at 1,000 mg after three months. After a month off, glutathione returned to baseline.
Is liposomal glutathione absorbed better?
Liposomal glutathione worked faster than an ordinary capsule. A liposome is a microscopic fatty sphere in which the glutathione is enclosed. A 2018 study in the European Journal of Clinical Nutrition gave 12 healthy people 500 or 1,000 mg of liposomal glutathione a day for a month.
- After a week: glutathione was already higher than at the start.
- After two weeks: plus 40 percent in whole blood, plus 28 percent in plasma and plus 100 percent in peripheral blood mononuclear cells.
- Oxidative stress: plasma 8-isoprostane, a marker of free radical damage, fell by 35 percent.
- Immunity: NK cell activity rose by up to 400 percent after two weeks.
It was a pilot study, without a placebo group and in only 12 people. The authors found no difference between 500 and 1,000 mg, but with such a small group they may have missed it. In 2026 a study in Antioxidants compared a new micellar form with ordinary glutathione. The micellar form at 300 mg gave an increase in blood glutathione about 2.5 times larger than an ordinary 500 mg dose.
What does glutathione by injection give?
An injection bypasses digestion completely, so glutathione reaches the blood intact. This was described most precisely by a 1991 study in the European Journal of Clinical Investigation. Ten healthy volunteers received an intravenous infusion of glutathione at a dose of 2 g per square metre of body surface.
The plasma glutathione level rose from 17.5 to 823 µmol/l. The half-life was 14 minutes, because glutathione leaves the blood quickly. Plasma cysteine rose from 8.9 to 114 µmol/l. The authors think cells take up the cysteine, which can support the building of their own glutathione.
Glutathione by injection therefore works like a fast delivery of building material for the cells.
We found no studies of glutathione given under the skin or into the muscle. The infusion results show what bypassing digestion gives, but they do not carry over directly to a subcutaneous injection.
Which form of glutathione to choose?
The choice depends on whether speed or convenience matters more. Below we set out the three forms by what the studies measured.
| Form | How fast | How strongly in the blood | Strength of the data |
|---|---|---|---|
| Intravenous injection | right after the infusion | from 17.5 to 823 µmol/l in plasma | study in 10 volunteers |
| Liposomal | after a week, peak after two | plus 40 percent in whole blood | pilot in 12 people, no placebo |
| Ordinary capsule | after a month, rising up to half a year | plus 30 to 35 percent at 1,000 mg | placebo-controlled study in 54 people |
A capsule takes patience and daily swallowing for months. The liposome raised the level faster in studies, and an injection gives the highest concentration, which however falls quickly. Studies of glutathione for specific uses are collected in the guides on glutathione and the liver and on glutathione and skin tone.
Where to buy glutathione for injection?
The shop has glutathione 1000 mg Bio-Peptide for 30 EUR, in stock. The pack contains a vial of freeze-dried powder and two 1 ml ampoules of solvent. Everything about the molecule is collected on the glutathione page.
How to prepare the solution from the vial is shown in the guide on how to reconstitute a peptide. Studies of glutathione and NAD given by injection are collected in the guide NAD and glutathione by injection. The product is material for laboratory research, not a medicine, so choosing a dose is a matter for a doctor.
Frequently asked questions
Is glutathione in capsules absorbed?
A single dose of about 3 g did not raise glutathione in the blood. A daily 1,000 mg for six months raised it by 30 to 35 percent in red blood cells, plasma and lymphocytes.
Is liposomal glutathione better than the ordinary kind?
It worked faster: in a pilot in 12 people it raised glutathione in whole blood by 40 percent after two weeks. There was no direct comparison with an ordinary capsule in that study.
How fast does glutathione by injection work?
After an intravenous infusion the plasma level rose from 17.5 to 823 µmol/l. The half-life was 14 minutes, and plasma cysteine rose more than tenfold.
Why is glutathione broken down in the digestive tract?
The enzyme gamma-glutamyl transferase in the gut and liver cuts glutathione into amino acids. This is why an ordinary capsule needs months to raise its level.
How much does glutathione for injection cost in the shop?
Glutathione 1000 mg Bio-Peptide costs 30 EUR and is in stock. The pack contains a vial and two ampoules of solvent.
Sources
- Witschi A, Reddy S, Stofer B, Lauterburg BH. The systemic availability of oral glutathione. European Journal of Clinical Pharmacology, 1992, 43(6): 667-669. https://doi.org/10.1007/BF02284971
- Allen J, Bradley RD. Effects of oral glutathione supplementation on systemic oxidative stress biomarkers in human volunteers. Journal of Alternative and Complementary Medicine, 2011, 17(9): 827-833. https://doi.org/10.1089/acm.2010.0716
- Richie JP, Nichenametla S, Neidig W et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. European Journal of Nutrition, 2015, 54(2): 251-263. https://doi.org/10.1007/s00394-014-0706-z
- Sinha R, Sinha I, Calcagnotto A et al. Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function. European Journal of Clinical Nutrition, 2018, 72(1): 105-111. https://doi.org/10.1038/ejcn.2017.132
- Solnier J, Du M, Zhang Y et al. A Targeted Metabolomic Assessment of Oral Glutathione Bioavailability and Safety in Humans: A Randomized Crossover Clinical Trial. Antioxidants, 2026, 15(3): 354. https://doi.org/10.3390/antiox15030354
- Aebi S, Assereto R, Lauterburg BH. High-dose intravenous glutathione in man. Pharmacokinetics and effects on cyst(e)ine in plasma and urine. European Journal of Clinical Investigation, 1991, 21(1): 103-110. https://doi.org/10.1111/j.1365-2362.1991.tb01366.x