Titus Thorne

Last Updated April 13, 2023

Titus Thorne

 April 13, 2023

Researchers interested in exploring the “master antioxidant” might be unclear on how to determine the right L-glutathione dosage for their next study. 

L-glutathione is the active form of glutathione, a tripeptide with positive effects on immune function, anti-aging, and muscle recovery. Extensive research into glutathione has shown that this short peptide: 

  • supports heart, liver, and brain health 
  • repairs DNA damage 
  • prevents cell death 

To guide our readers along, we have compiled this educational L-glutathione dosage calculator and guide to its benefits and safety. 

Read through the end as we include our recommendation on where to buy research-grade peptides online.

Disclaimer: Peptides.org contains information about products that are intended for laboratory and research use only, unless otherwise explicitly stated. This information, including any referenced scientific or clinical research, is made available for educational purposes only. Peptides.org makes every effort to ensure that any information it shares complies with national and international standards for clinical trial information and is committed to the timely disclosure of the design and results of all interventional clinical studies for innovative treatments publicly available or that may be made available. However, research is not considered conclusive. Peptides.org makes no claims that any products referenced can cure, treat or prevent any conditions, including any conditions referenced on its website or in print materials.

What is L-Glutathione?

Glutathione (GSH) is an antioxidant that is present in plants, animals, and fungi, and found in nearly every cell of the human brain and body.

It protects brain mitochondria from oxidative stress and recycles other antioxidants, such as vitamins C and E. These key properties of glutathione result in enhanced immune function, protection from age-related disease, reduced inflammation, and the purging of heavy metals—among its many other functions.

Natural glutathione production may be stimulated through the consumption of sulfur-rich vegetables like onions, garlic, spinach, and cauliflower. Animal food sources such as eggs and chicken, as well as dairy products, are also known to boost glutathione production [1, 2].

But as we age, natural glutathione production falters. Glutathione deficiency is linked to oxidative stress, which accelerates aging and the pathogenesis of a range of diseases. A lack of this important antioxidant can also negatively impact vision, skin health, and clarity of thought [3].

This is where supplementation with L-glutathione, the active form of glutathione, comes in. Composed of the amino acids L-cysteine, L-glutamic acid, and glycine, the tripeptide is synthesized by the addition of the C-terminal of gamma-glutamylcysteine catalyzed by glutathione synthetase. Glutathione is broken down in the liver by an enzyme called gamma-glutamyl transferase (GGT) [4].

Read on to discover the research-backed benefits of L-glutathione administration.

L-Glutathione Dosage

L-Glutathione Benefits

Research indicates that L-glutathione administration promotes the overall health and well-being of test subjects, particularly as the natural production of glutathione dwindles with age.

Here is a summary of select findings in relation to glutathione research to date.

  • Glutathione can prevent and repair oxidative damage by capturing free radicals throughout the body and recharging other antioxidants, thus preventing chronic disease and inflammation. Researchers have observed this protective effect through glutathione’s activation of the Nrf2/HO-1 signaling pathway [4].
  • Researchers have found that glutathione can have an anti-aging effect while helping to reduce signs of aging in the skin. For example, Thai researchers conducted a 12-week study on healthy female subjects to see if GSH administration could exert a visual anti-aging effect, in addition to its well-known anti-melanogenic effect. A significant number of the subjects exhibited less wrinkles, better skin elasticity, and reduced photoaging as a result of oral glutathione administration [5].
  • Glutathione levels decline in many types of tissue as we age, and this decline can have a significant impact on brain health. In fact, reduced levels of glutathione have been linked to both Parkinson’s disease and neuronal damage following stroke. Because glutathione provides critical support in protecting cells against stress, researchers have found glutathione to be highly protective against stress-induced neuronal damage [6].
  • Glutathione is vital to cartilage health since cartilage is particularly susceptible to age-related glutathione oxidation. In a bovine cartilage study, researchers found that inducing oxidant stress (i.e. through exercise) coupled with rest and glutathione administration can optimize glutathione levels in the joints and delay the aging of cartilage [7].
  • Glutathione can better prepare the immune system to ward off disease. In a recent study involving the oral administration of liposomal glutathione, human subjects who took 500mg or 1000mg GSH daily had elevated stores of glutathione, and exhibited improvements in markers of immune function and oxidative stress [8].
  • Glutathione can boost athletic performance and exercise output. In a study on both mice and humans, researchers found that pre-exercise glutathione administration improved lipid metabolism and acidification in the skeletal muscle of the subjects, resulting in less muscle fatigue [9]. In another study, researchers found that combining glutathione with L-citrulline maximizes the production of nitric oxide, which dilates the blood vessels to improve blood flow and oxygen delivery to muscles and tissue [10].
  • Glutathione is also known to promote long-term eye health, namely of the retina, lens, and cornea. The peptide supports the Muller cells, which regulate retinal function and protect the eye against pathogens [11]. It has also been shown to decrease oxidative stress in the eye and delay age-related changes, including loss of visual acuity and the incidence of cataracts [12].

L-Glutathione Side Effects

Glutathione administration has been shown to be well-tolerated, safe, and non-toxic across a variety of research studies and cases.

The research does not link glutathione to any serious adverse effects, but it may cause some mild side effects.

For example, a small number of subjects reported the following mild side effects in the course of a four-week glutathione study at the dose of 1g/day [13]:

  • Flatulence
  • Loose stools
  • Flushing
  • Weight gain

In a more specialized study involving cystic fibrosis patients and much higher glutathione doses, some of the patients reported tightness in the torso, diarrhea, and fever-like symptoms [14].

Researchers should also note that low-quality L-glutathione sourced from a disreputable vendor may contain contaminants that can cause acute systemic toxicity. Researchers are thus well-advised to source injectable L-glutathione only from reputable sources, since there is always the risk of adverse effects linked to administering a contaminated product.

L-Glutathione Dosage

L-Glutathione Dosage Calculator and Guide

The research indicates that the most effective forms of glutathione administration are through injection or the inhalation of a nasal preparation.

Injecting glutathione, whether intramuscularly or subcutaneously, is the easiest means of administering the peptide in large doses, and is the most commonly employed method in the research.

Experts agree that injectable L-glutathione should be handled and administered only by qualified researchers or laboratory professionals.

To properly reconstitute L-glutathione for injection, a research will need the following items on hand:

For reference purposes, researchers may administer the following L-glutathione dosage as part of a systemic detoxification and regeneration protocol:

  • Daily Dosage: 600mg.
  • Frequency: Weekly.
  • Study Duration: L-glutathione may be administered weekly for an indefinite duration as needed.
  • Notes: Our preferred vendor sells 600mg L-glutathione vials, as detailed below.

Where to Buy L-Glutathione Online? | 2023 Edition

For a peptide source that is recognized around the world as the benchmark of quality in the industry, Peptide Sciences sits atop our list.

The American company is the retailer of choice for leading researchers due to its unmatched quality and commitment to client satisfaction. The main benefits of our favorite vendor are:

100% verified product quality

To support its claims of a minimum 99% purity level of all items in its vast catalog of research peptides, this vendor provides valid third-party lab test results on all products. The testing methods of MS and HPLC are recognized as the standard bearers for accuracy. Plus, the retailer offers great transparency on its manufacturing practices, carried out in the USA in compliance with WHO and Good Manufacturing Practice guidelines with trusted partners.

Top-tier products at great prices

Domestic manufacturing allows Peptide Sciences to maintain low prices on its premium selection. A 600mg vial of research-grade L-glutathione currently retails for $82, and the retailer also offers price reductions on bulk purchases.

Rapid and low-cost deliveries

Low-cost shipments are offered within the United States and many international destinations. Shipping fees are waived on domestic orders over $200. While domestic shipments usually arrive within just 3 days, international orders are typically received within just 7-10 business days.

Safe and easy checkout

Checkout is a breeze on the SSL-encrypted website, and a convenient range of payment methods are accepted, including crypto, credit cards, and many third-party processors.

Winning customer service

Peptide Sciences offers unmatched customer service in its commitment to full client satisfaction. Knowledgeable staff is accessible with quick response times to customer queries. Erroneous orders are happily replaced without charge, and the educational website is packed with scientific articles and peer-reviewed sources.

Check out Peptide Sciences today to access the best peptides on the web!

Buy Best L-Glutathione Capsule from our #1 recommended vendor...

L-Glutathione Dosing | Verdict

Glutathione is known as the “master antioxidant” and regulates a range of key biochemical processes. It is found in many forms of tissue, but unfortunately declines with age.

There are numerous research-backed benefits to administering this peptide, and in this guide we have covered brain health, cartilage health, anti-aging, athletic performance, and more.

With a favorable safety profile, injectable L-glutathione may be dosed in a variety of ways depending on your research objective and factors related to your test subject.

For more information about L-glutathione or to place an order, visit Peptide Sciences today.


  1. Nimni ME, Han B, Cordoba F. Are we getting enough sulfur in our diet?. Nutr Metab (Lond). 2007;4:24. Published 2007 Nov 6. doi:10.1186/1743-7075-4-24
  2. In-Young Choi, Phil Lee, Douglas R Denney, Kendra Spaeth, Olivia Nast, Lauren Ptomey, Alexandra K Roth, Jo Ann Lierman, Debra K Sullivan, Dairy intake is associated with brain glutathione concentration in older adults, The American Journal of Clinical Nutrition, Volume 101, Issue 2, February 2015, Pages 287–293, https://doi.org/10.3945/ajcn.114.096701
  3. Wu G, Fang YZ, Yang S, Lupton JR, Turner ND. Glutathione metabolism and its implications for health. J Nutr. 2004;134(3):489-492. doi:10.1093/jn/134.3.489
  4. Kwon DH, Cha HJ, Lee H, Hong SH, Park C, Park SH, Kim GY, Kim S, Kim HS, Hwang HJ, Choi YH. Protective Effect of Glutathione against Oxidative Stress-induced Cytotoxicity in RAW 264.7 Macrophages through Activating the Nuclear Factor Erythroid 2-Related Factor-2/Heme Oxygenase-1 Pathway. Antioxidants (Basel). 2019 Apr 1;8(4):82. doi: 10.3390/antiox8040082. PMID: 30939721; PMCID: PMC6523540.
  5. Weschawalit S, Thongthip S, Phutrakool P, Asawanonda P. Glutathione and its antiaging and antimelanogenic effects. Clin Cosmet Investig Dermatol. 2017 Apr 27;10:147-153. doi: 10.2147/CCID.S128339. PMID: 28490897; PMCID: PMC5413479.
  6. Maher P. The effects of stress and aging on glutathione metabolism. Ageing Res Rev. 2005 May;4(2):288-314. doi: 10.1016/j.arr.2005.02.005. PMID: 15936251.
  7. Zhu S, Makosa D, Miller B, Griffin TM. Glutathione as a mediator of cartilage oxidative stress resistance and resilience during aging and osteoarthritis. Connect Tissue Res. 2020 Jan;61(1):34-47. doi: 10.1080/03008207.2019.1665035. Epub 2019 Sep 15. PMID: 31522568; PMCID: PMC6884680.
  8. Sinha R, Sinha I, Calcagnotto A, Trushin N, Haley JS, Schell TD, Richie JP Jr. Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function. Eur J Clin Nutr. 2018 Jan;72(1):105-111. doi: 10.1038/ejcn.2017.132. Epub 2017 Aug 30. PMID: 28853742; PMCID: PMC6389332.
  9. Aoi W, Ogaya Y, Takami M, Konishi T, Sauchi Y, Park EY, Wada S, Sato K, Higashi A. Glutathione supplementation suppresses muscle fatigue induced by prolonged exercise via improved aerobic metabolism. J Int Soc Sports Nutr. 2015 Feb 6;12:7. doi: 10.1186/s12970-015-0067-x. PMID: 25685110; PMCID: PMC4328900.
  10. Aoi W, Ogaya Y, Takami M, Konishi T, Sauchi Y, Park EY, Wada S, Sato K, Higashi A. Glutathione supplementation suppresses muscle fatigue induced by prolonged exercise via improved aerobic metabolism. J Int Soc Sports Nutr. 2015 Feb 6;12:7. doi: 10.1186/s12970-015-0067-x. PMID: 25685110; PMCID: PMC4328900.
  11. Ganea E, Harding JJ. Glutathione-related enzymes and the eye. Curr Eye Res. 2006 Jan;31(1):1-11. doi: 10.1080/02713680500477347. PMID: 16421014.
  12. Babizhayev MA. New concept in nutrition for the maintenance of the aging eye redox regulation and therapeutic treatment of cataract disease; synergism of natural antioxidant imidazole-containing amino acid-based compounds, chaperone, and glutathione boosting agents: a systemic perspective on aging and longevity emerged from studies in humans. Am J Ther. 2010 Jul-Aug;17(4):373-89. doi: 10.1097/MJT.0b013e3181d6b6c3. PMID: 20463577.
  13. Allen J, Bradley RD. Effects of oral glutathione supplementation on systemic oxidative stress biomarkers in human volunteers. J Altern Complement Med. 2011;17(9):827-833. doi:10.1089/acm.2010.0716
  14. Visca A, Bishop CT, Hilton SC, Hudson VM. Improvement in clinical markers in CF patients using a reduced glutathione regimen: an uncontrolled, observational study. J Cyst Fibros. 2008;7(5):433-436. doi:10.1016/j.jcf.2008.03.006

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