Can I Take Collagen and Glutathione Together?

Yes, you can take collagen and glutathione together: there is no interaction, and there is a real connection: collagen is unusually rich in glycine, and glycine is one of the three amino acids the body uses to make its own glutathione.⁶ Collagen peptides have 26 randomised trials in 1,721 people for skin hydration and elasticity;¹ the joint, bone and muscle trials are in the Wellgard collagen guide. Oral glutathione has fewer trials: a six-month trial at 250 and 1,000 mg a day found body stores rising by 30 to 35% at the higher dose, a supplier-funded four-week trial found blood glutathione unchanged, and reviews call the small, short skin-lightening trials inconclusive.^{2, 3, 10} Neither has an authorised health claim in Great Britain, so nothing below is a claim for either.²¹

Sources checked on 29 October 2026.

What glutathione is

Glutathione is a small molecule of three amino acids, glycine, cysteine and glutamate, that every cell makes; trial authors describe it as the most abundant antioxidant the body makes for itself.^{2, 3} In a study of 169 healthy adults, red-cell glutathione at 60 to 79 was 17% lower than at 20 to 39.¹⁷ The research question is whether swallowing glutathione raises the glutathione inside cells, because part of an oral dose is broken into its amino acids in the gut. Two approaches: daily dosing over months, and liposomal glutathione, which wraps the molecule in a phospholipid layer; its one trial, a four-week pilot in 12 adults with no placebo group, funded by a liposomal-glutathione maker, found whole-blood glutathione up to 40% higher by two weeks.¹⁸

What glutathione supplements have shown

A four-week randomised trial of 500 mg twice a day in 40 adults found no change in blood glutathione or markers of oxidative stress.² In a six-month trial of 250 or 1,000 mg a day in 54 adults, glutathione in red cells, plasma and lymphocytes rose by 30 to 35% at the higher dose and by 17 to 29% in blood and red cells at the lower one, the ratio of oxidised to reduced glutathione fell, and the increase disappeared within a month of stopping.³ On skin lightening, a four-week placebo-controlled trial in 60 students found melanin index lower than placebo at two of six skin sites, and a supplier-funded 12-week placebo-controlled trial in 60 women taking 250 mg a day found no significant overall change in melanin index.^{9, 4} Systematic reviews in 2019 and 2025 call the evidence inconclusive and the results unsustainable.^{10, 11} Separately, trials in older adults have given glutathione's building blocks, glycine and N-acetylcysteine: 16 weeks in 24 older adults corrected red-cell glutathione and several markers of ageing, while the largest trial, two weeks in 114 healthy adults of around 65, found no rise in total glutathione overall.^{5, 16}

Do glutathione and collagen complement each other?

In one specific way. Collagen is rich in glycine, proline and hydroxyproline, so a daily serving of peptides supplies meaningful glycine.⁶ In a small metabolic study, eight older adults had lower red-cell glycine and cysteine than eight younger adults and made glutathione at about half the rate; two weeks of both amino acids restored synthesis to the younger level.¹⁵ What collagen does not do is act as an antioxidant itself, and what glutathione does not do is build collagen. Does collagen make you look better goes through the skin trials.

Is it safe to take collagen and glutathione together?

Yes. The trials reported few glutathione side effects. In the four-week trial, five people reported flatulence or loose stools, two flushing and one weight gain, with no change in blood tests;² and in the 12-week skin trial two of 60 women withdrew after raised liver-function tests.⁴ In four collagen peptide trials in knee osteoarthritis, side effects were not statistically more frequent than with placebo, with very low certainty.⁷ Two notes on glutathione alone. First, injections and drips: the MHRA's rules allow an unlicensed medicine to be supplied only for an individual patient's special clinical need, on a prescriber's order, so skin-whitening drips and injections from clinics and salons are unlicensed uses, and the MHRA's stated position, carried by the cosmetic practitioners' council, is that cosmetic use is not an admissible special need.^{12, 20} A 2025 review of injected glutathione lists anaphylaxis and liver toxicity among the harms reported.¹³ In June 2025 the Chartered Trading Standards Institute warned that salon glutathione drips are entirely unregulated in the UK, citing a broadcaster's count of more than 300 salons offering them and campaign-group reports of anaphylaxis needing hospital treatment, kidney strain and infections.¹⁹ Second, inhaled glutathione: in eight people with mild asthma, nebulised glutathione narrowed the airways (FEV1 down 19%) and caused cough in four and breathlessness in three, which the authors attributed to sulphite forming from glutathione; no study links capsules to asthma, but anyone with asthma or sulphite sensitivity should ask a pharmacist or GP first.¹⁴ Is there a downside to taking collagen covers collagen's own cautions, what vitamins should I take with collagen the other pairings.

How is collagen different from glutathione?

Collagen is a structural protein, around 25 to 30% of all the protein in the body, the framework of skin, bone, cartilage, tendon and blood vessels; the supplement is taken in grams.⁶ Glutathione, made inside every cell, is taken in milligrams. Collagen peptides are absorbed as short fragments that appear in the blood in proportion to the dose.⁸

What we don't know

Whether daily oral glutathione changes anything a person can see or feel: the six-month trial measured blood stores, not skin or symptoms.³ Whether glutathione protects collagen from breakdown, an online claim no trial has tested. Whether any skin-lightening effect lasts: none of the trials we found measured skin after stopping.^{10, 11} These are gaps in the evidence, not findings against either supplement.

Frequently asked questions

Can I take collagen and glutathione at the same time?

Yes, in the same glass if you like; neither affects the other's absorption.

Does collagen contain glutathione?

No: it contains glycine, one of glutathione's three amino acids, and almost no cysteine.

Which is better for skin, collagen or glutathione?

Different questions: collagen trials measured skin hydration and elasticity over two to twelve weeks; glutathione's skin studies measured melanin index in two placebo-controlled trials of 60 people each, over four and 12 weeks. Great Britain authorises no skin claim for either.^{1, 9, 4, 21}

Sources

1. Pu SY, et al. Effects of oral collagen for skin anti-aging: a systematic review and meta-analysis. Nutrients, 2023. Pooled analysis, 26 randomised trials, 1,721 people, 2 to 12 weeks; no conflicts declared. PubMed 37432180.
2. Allen J, Bradley RD. Effects of oral glutathione supplementation on systemic oxidative stress biomarkers in human volunteers. Journal of Alternative and Complementary Medicine, 2011. Placebo-controlled trial, 40 adults, 500 mg twice daily, 4 weeks; supplier-funded. PubMed 21875351.
3. Richie JP, et al. Randomized controlled trial of oral glutathione supplementation on body stores of glutathione. European Journal of Nutrition, 2015. Placebo-controlled trial, 54 adults, 250 or 1,000 mg a day, 6 months; funding not stated on PubMed. PubMed 24791752.
4. Weschawalit S, et al. Glutathione and its antiaging and antimelanogenic effects. Clinical, Cosmetic and Investigational Dermatology, 2017. Placebo-controlled trial, 60 women, 250 mg a day, 12 weeks; supplier-funded. PubMed 28490897.
5. Kumar P, et al. Supplementing glycine and N-acetylcysteine (GlyNAC) in older adults improves glutathione deficiency, oxidative stress, mitochondrial dysfunction, inflammation, physical function, and aging hallmarks: a randomized clinical trial. Journals of Gerontology Series A, 2023. Placebo-controlled trial, 24 older adults, 16 weeks; funding not stated on PubMed. PubMed 35975308.
6. Paul C, Leser S, Oesser S. Significant amounts of functional collagen peptides can be incorporated in the diet while maintaining indispensable amino acid balance. Nutrients, 2019. Dietary modelling study; manufacturer-linked authors. PubMed 31096622.
7. Lin CR, et al. Analgesic efficacy of collagen peptide in knee osteoarthritis: a meta-analysis of randomized controlled trials. Journal of Orthopaedic Surgery and Research, 2023. Pooled analysis, 4 randomised trials, 507 people with knee osteoarthritis; no conflicts declared. PubMed 37717022.
8. Shigemura Y, et al. Dose-dependent changes in the levels of free and peptide forms of hydroxyproline in human plasma after collagen hydrolysate ingestion. Food Chemistry, 2014. Dose study, 4 volunteers; author employed by a marine ingredients company. PubMed 24767063.
9. Arjinpathana N, Asawanonda P. Glutathione as an oral whitening agent: a randomized, double-blind, placebo-controlled study. Journal of Dermatological Treatment, 2012. Placebo-controlled trial, 60 students, 500 mg a day, 4 weeks; funding not stated on PubMed. PubMed 20524875.
10. Dilokthornsakul W, et al. The clinical effect of glutathione on skin color and other related skin conditions: a systematic review. Journal of Cosmetic Dermatology, 2019. Systematic review, 4 studies; funding not stated on PubMed. PubMed 30895708.
11. Sarkar R, et al. Glutathione as a skin-lightening agent and in melasma: a systematic review. International Journal of Dermatology, 2025. Systematic review; funding not stated on PubMed. PubMed 39444151.
12. MHRA. Supply unlicensed medicinal products (specials). gov.uk, updated 29 January 2025. gov.uk.
13. Alzahrani TF, et al. Exploring the safety and efficacy of glutathione supplementation for skin lightening: a narrative review. Cureus, 2025. Narrative review; no funding received. PubMed 40013212.
14. Marrades RM, et al. Nebulized glutathione induces bronchoconstriction in patients with mild asthma. American Journal of Respiratory and Critical Care Medicine, 1997. Crossover trial, 8 people with mild asthma; funding not stated on PubMed. PubMed 9279219.
15. Sekhar RV, et al. Deficient synthesis of glutathione underlies oxidative stress in aging and can be corrected by dietary cysteine and glycine supplementation. American Journal of Clinical Nutrition, 2011. Metabolic study, 8 older and 8 younger adults, 2 weeks; funding not stated on PubMed. PubMed 21795440.
16. Lizzo G, et al. A randomized controlled clinical trial in healthy older adults to determine efficacy of glycine and N-acetylcysteine supplementation on glutathione redox status and oxidative damage. Frontiers in Aging, 2022. Randomised trial, 114 adults of around 65, 2 weeks; manufacturer-employed authors. PubMed 35821844.
17. Lang CA, et al. Low blood glutathione levels in healthy aging adults. Journal of Laboratory and Clinical Medicine, 1992. Cross-sectional study, 169 adults aged 20 to 94; funding not stated on PubMed. PubMed 1431500.
18. Sinha R, et al. Oral supplementation with liposomal glutathione elevates body stores of glutathione and markers of immune function. European Journal of Clinical Nutrition, 2018. Open-label pilot, 12 adults, 4 weeks; funded by a liposomal glutathione maker. PubMed 28853742.
19. Chartered Trading Standards Institute. Public warning issued about dangerous glutathione skin whitening IV drips. 26 June 2025. tradingstandards.uk.
20. Joint Council for Cosmetic Practitioners. Glutathione and unlicensed medicines used in cosmetic procedures. Undated; cites MHRA 2016 guidance. jccp.org.uk.
21. Department of Health and Social Care. Great Britain nutrition and health claims (NHC) register, page last updated 19 May 2026. gov.uk.

Spotted something out of date? Email support@wellgard.co.uk with the page address and the sentence.

This article is general information, not medical advice. No glutathione medicine is licensed in the UK for skin lightening, and clinic and salon injections and drips are unlicensed uses; ask a GP, a dermatologist or a pharmacist before considering any injected product, and report any reaction through the MHRA Yellow Card scheme.