Glutathione injection: benefits, skin lightening claims, dosage and side effects

Glutathione is a small molecule made inside cells from three amino acids: glutamate, cysteine and glycine. That makes it a tripeptide, a very short peptide. Its cysteine carries a sulphur-containing thiol group, which lets it neutralise reactive oxygen species and keep the inside of the cell in a reduced, protected state ^[1]. Most of it exists in this reduced form, which is why products are labelled reduced glutathione, L-glutathione or GSH.

A glutathione injection is this molecule dissolved in sterile liquid and given by needle, into a vein, a muscle or the fat under the skin. The L-glutathione injection, glutathione peptide injection and injection glutathione that people search for are the same product. Clinics usually give it as an intravenous drip, often mixed with vitamin C; peptide stores sell freeze-dried vials, for example of 600 mg or 1,200 mg, labelled for research use.

PepFinder lists glutathione because peptide stores sell it alongside other research peptides, in the same vial format, and buyers compare its price and testing in the same way. It is often sold next to NAD+, a coenzyme that, unlike glutathione, is not a peptide.

Glutathione's reputation as a skin-lightening agent rests on its effects on melanin. Laboratory work suggests it inhibits tyrosinase, the key enzyme in melanin production, both directly and indirectly, and shifts pigment cells from making dark brown-black eumelanin towards lighter red-yellow phaeomelanin ^[1].

That mechanism also raises a concern. Reviewers have pointed out that switching from brown to red melanin could, in theory, increase the risk of sun-induced skin cancer in people whose darker skin previously protected them ^[9]. The Philippine FDA cited the same theoretical long-term skin cancer concern in its 2019 advisory ^[12]. No study has measured whether this happens.

In medicine, injectable glutathione has been studied mainly as a protective add-on to chemotherapy. In a 1995 randomised, placebo-controlled trial in 50 people with advanced gastric cancer receiving cisplatin, glutathione given by drip before each cisplatin dose and by intramuscular injection on the following days reduced nerve damage: after 15 weeks, 4 of 24 assessable patients in the glutathione group had neurotoxicity against 16 of 18 on placebo ^[17]. The Philippine FDA states that injectable glutathione is approved there as an adjunct treatment in cisplatin chemotherapy ^[12].

It has also been studied in Parkinson's disease, where glutathione is depleted early in the course of the illness ^[16]. In a pilot trial of 21 people, intravenous glutathione three times a week for four weeks was well tolerated but did not significantly change symptom scores compared with placebo ^[15]. A later trial of glutathione nasal spray, described below, also found no difference from placebo ^[16].

Outside hospitals, the main use is cosmetic: glutathione injection for skin whitening, sold by beauty clinics, spas and online sellers. The Philippine FDA noted that salons, spas and clinics offer glutathione and vitamin C drips for this purpose ^[12].

Claimed glutathione injection benefits include lighter and more even skin, fewer dark spots, detoxification, liver support, better energy and anti-ageing effects. For skin, the controlled evidence is mostly for oral and topical glutathione, not injections.

A 2025 systematic review of glutathione for skin lightening and melasma found five randomised controlled trials and one open study of oral glutathione, at 250 mg once a day, 250 mg twice a day or 500 mg once a day, that showed a significant reduction in the melanin index compared with placebo. Topical 0.5% glutathione beat 0.1% glutathione and placebo, and topical plus oral beat either alone. The review found only one placebo-controlled study of intravenous glutathione, in which 6 of 16 people responded against 3 of 16 on placebo, a difference that was not statistically significant (p = 0.054). The authors concluded that IV glutathione is contraindicated because of lack of efficacy and side effects ^[7].

A 2026 review focused on intravenous glutathione reached a similar conclusion. It found only modest and variable improvements in pigmentation, in small studies with differing methods and short follow-up, noted that routine co-administration of vitamin C makes the effect of glutathione itself hard to separate, and judged the evidence too limited to justify routine cosmetic use ^[8].

For liver claims, the main human study was of oral glutathione. In an open-label pilot study, 29 people with non-alcoholic fatty liver disease who took 300 mg a day for four months, after three months of diet and exercise advice, had lower ALT liver enzyme levels. There was no placebo group, and the authors called for larger trials ^[18].

The oral trials are small but controlled. In a 2012 Thai trial, 60 medical students took 500 mg of glutathione a day, in two doses, or placebo for four weeks. Melanin indices fell at all six sites measured in the glutathione group, and the difference from placebo was significant at two sites, the face and a sun-exposed forearm. The authors concluded that oral glutathione lightened skin in a small number of subjects and that long-term safety had not been established ^[5].

A 2017 trial randomised healthy women to 250 mg a day of reduced glutathione, 250 mg a day of oxidised glutathione, or placebo for 12 weeks. Melanin index and UV spots tended to be lower than placebo in both glutathione groups, and some sites showed fewer wrinkles with the reduced form. There were no serious adverse effects ^[6].

For intravenous glutathione, a 2016 review found no published study of IV glutathione for skin lightening and no data on its safety in long-term use for any purpose ^[9]. The single placebo-controlled IV trial identified since then did not show a significant effect ^[7].

Glutathione injection before and after photos are widely used in advertising. They are not controlled: lighting, camera settings, make-up, sun exposure, season and other treatments all change between pictures, and sellers choose which photos to show. They cannot show what glutathione itself did. The trials above measured melanin with instruments against a placebo group, and found smaller, site-specific effects ^[5][7].

Reviewers describe the skin effects of oral and topical glutathione as unsustainable, and list the duration of treatment and how long any lightening lasts as unanswered questions ^[1][7].

The glutathione injection vs oral question turns on absorption. An early study gave seven healthy volunteers a single 3 g oral dose and found no significant rise in blood glutathione over 4.5 hours. The authors concluded that glutathione is broken down in the gut and liver and that a single oral dose cannot raise blood levels to a useful extent ^[2].

Longer studies found otherwise. In a six-month randomised trial in 54 adults, 250 or 1,000 mg of oral glutathione a day raised glutathione in blood, red cells, plasma and lymphocytes, by 30 to 35% at the higher dose, with levels returning to baseline a month after stopping ^[3]. A 2026 crossover trial in 14 adults found that a micellar formulation produced higher blood glutathione exposure than standard glutathione capsules, and no changes in liver or kidney safety markers over 30 days at 600 mg a day ^[4]. That study was run by the formulation's developer.

Injection delivers glutathione straight into the blood, but no published trial has compared glutathione injections with oral glutathione for skin or any other outcome. For skin lightening, the better-controlled evidence is for oral and topical forms, while the only placebo-controlled IV trial was negative ^[7].

Glutathione IV injection, as a drip or a slow push into a vein, is the form used in the cancer, Parkinson's and skin studies ^[15][17][7]. Glutathione IM injection, into a muscle, was used in the 1995 cisplatin trial at 600 mg a day on the days after chemotherapy ^[17]. People also ask whether glutathione injection should be IM or IV; no study has compared the two routes directly.

We found no published human study of glutathione subcutaneous injection, the route usually intended for peptide-store vials. There are therefore no data on how much reaches the blood, or on local reactions, by that route. The same is true of a glutathione intramuscular injection given on its own for skin.

Glutathione has also been given as a nasal spray and by nebuliser. In a Parkinson's trial, 45 people used a glutathione nasal spray of 100 mg or 200 mg or saline three times a day for three months; all groups improved, including placebo, and neither dose beat placebo ^[16]. Inhaled glutathione is covered under side effects below.

PepFinder does not recommend doses. These are the glutathione injection doses used in published human studies, with route and purpose.

Cisplatin trial: 1.5 g per square metre of body surface by 15-minute drip before chemotherapy, then 600 mg by intramuscular injection on days two to five ^[17]. Parkinson's pilot: 1,400 mg by intravenous infusion three times a week for four weeks ^[15]. Nasal spray: 100 mg or 200 mg three times a day for three months ^[16].

Oral studies used 250 to 1,000 mg a day ^[3][5][6][7] and 300 mg a day for fatty liver ^[18].

For skin lightening by injection, the Philippine FDA stated in 2019 that there were no published guidelines on appropriate dosing regimens or duration of treatment ^[12]. So the glutathione injection dosage chart, per-week and per-month figures circulating online, and any glutathione injection dosage per day for skin, are not taken from controlled trials.

Questions about glutathione injection dosing in units or mL are arithmetic. A 600 mg vial dissolved in 3 mL of liquid contains 200 mg per mL; on a U-100 insulin syringe, which holds 100 units per mL, each unit then holds 2 mg. A 1,200 mg vial in 6 mL gives the same concentration.

Our glutathione reconstitution calculator does this for any vial and volume, and our guide to bacteriostatic water covers the usual diluent. Neither is advice to inject glutathione.

In controlled medical trials, intravenous glutathione was well tolerated over short courses: in the Parkinson's pilot, adverse events were similar with glutathione and placebo and nobody withdrew because of them ^[15]. Most trials reviewed in 2016 reported no or minimal side effects, but they lasted only a few doses or 4 to 12 weeks ^[9].

For cosmetic injections, regulators and reviewers list more serious concerns. The Philippine FDA listed toxic effects on the liver, kidneys and nervous system, a possible risk of Stevens-Johnson syndrome, and transmission of HIV and hepatitis B and C, particularly when non-medical staff inject it in non-sterile settings ^[12]. A 2026 review added hypersensitivity reactions and possible kidney and hormonal effects ^[8].

Serious reactions have been published as case reports. In 2025, US doctors described a 33-year-old woman who developed Stevens-Johnson syndrome and toxic epidermal necrolysis, a severe skin and mucous membrane reaction, after an IV infusion containing glutathione, vitamin C and vitamin D ^[13]. A single case cannot prove cause, but the authors noted earlier reports linking glutathione to the same reaction.

Product quality is a separate risk. In 2019 the FDA reported that eight patients became ill after receiving injections compounded from glutathione powder labelled as a dietary supplement. Seven developed nausea, vomiting, light-headedness, chills and body aches within minutes, and one was hospitalised with low blood pressure and difficulty breathing. FDA testing found bacterial endotoxin up to five times the appropriate limit, It warned compounders not to use that supplier's glutathione powder for sterile injectables, and said all ingredients for sterile injections should be made to specifications suitable for that route ^[11].

Inhaled glutathione can tighten the airways. In eight people with mild asthma, nebulised glutathione caused marked narrowing of the airways, cough and breathlessness, which the authors attributed to sulphite formation ^[14]. Anyone searching for side effects of glutathione injection should also know that long-term safety of repeated injections has not been studied ^[9].

In 2015 the US FDA warned consumers that injectable skin lightening products are unapproved drugs that carry safety risks, and that people using them are injecting a substance whose ingredients and manufacture they cannot know. It stated that it has not approved any injectable drug for skin whitening or lightening, named glutathione, vitamin C, collagen and human placenta among the ingredients of such products, and described the 2014 seizure by US Marshals of glutathione whitening kits sold by a US company ^[10].

The FDA's 2019 alert on contaminated glutathione concerned compounded injectables made from supplement-grade powder, rather than skin lightening specifically ^[11]. The Philippine FDA's 2019 advisory warned the public directly against injectable glutathione for skin lightening, stating that no clinical trials had evaluated it for that use and that no injectable product was approved for it ^[12].

Clinics often combine the two in one drip, and vitamin C and glutathione injection is a common search. There is a biological rationale: in a small study of healthy adults, 500 mg of oral vitamin C a day for two weeks raised red blood cell glutathione by nearly 50% compared with baseline, and a higher dose of 2,000 mg added no further rise ^[19]. That study used oral vitamin C and measured glutathione levels, not skin colour.

No controlled trial has tested glutathione with vitamin C injections for skin lightening. The combination also adds its own risks: the Philippine FDA noted that vitamin C injections may form kidney stones if the urine is acidic, and that large doses have led to haemodialysis in people with G6PD deficiency ^[12]. The 2026 review noted that routine co-administration of vitamin C makes it hard to tell what glutathione contributes ^[8].

Clinics also pair glutathione with NAD+ drips. A 2026 review of intravenous longevity therapies, which covered both, found placebo-controlled trials scarce and described these drips as experimental rather than evidence-based ^[20]. No study has tested the two together.

Peptide-store glutathione is supplied as a freeze-dried powder. As with other vials, the usual practice is to keep it cold, dry and away from light, and to refrigerate it after mixing. See how to store peptides. The FDA's 2019 alert is a reminder that powder made for supplements is not made to the standard required for sterile injection ^[11].

In the US, the FDA has stated that it has not approved any injectable drug for skin whitening or lightening, and has described such products as unapproved new drugs ^[10]. In the Philippines, injectable glutathione is approved only as an adjunct in cisplatin chemotherapy, and the regulator has warned against its use for skin lightening ^[12].

We have not verified glutathione's status as a medicine or supplement in each PepFinder market. See our pages on legal status by country and the UK legal status page for how unlicensed injectable products are treated.

PepFinder does not sell glutathione. To compare vial prices across research suppliers, see glutathione prices. For a glutathione injection UK search, compare glutathione suppliers in the UK, and for Australia see glutathione prices in Australia. A glutathione injection price quoted by a clinic covers a supervised treatment, so it cannot be compared directly with the price of a research vial.

Because contamination has caused harm, testing matters more than price. A certificate of analysis should show identity, purity and content, and for injectables ideally sterility and endotoxin results; see how to read a COA and third-party peptide testing. Our list of third-party tested suppliers, our guide on how to spot a fake peptide supplier and our methodology explain how we assess vendors.