Glutathione Dosage, half-life & reference guide

Week by week.

What to expect in the first 8 weeks

Onset

Weeks (skin tone, when reported)

Peak effect

Unknown

Duration

Ongoing or in blocks

1. Day 1–14Clinical

   Here and gone within the hour

   Injected glutathione doesn't linger: after an IV infusion it was cleared from the blood with a half-life of about 14 minutes, broken into amino acids that cells reuse for their own. Commonly reported: stinging at the injection site and little else to feel early on.

   The science

   Aebi 1991: in 10 healthy volunteers, an IV infusion of 2 g/m² raised plasma glutathione from 17.5 to 823 µmol/L, with a half-life of 14.1 ± 9.2 minutes; plasma cysteine rose about 13-fold and urinary glutathione 300-fold. Outside cells, glutathione is broken down by gamma-glutamyl transpeptidase and a dipeptidase into cysteine and glycine (Forman 2009). SubQ and IM injection have never been measured.

   Sources

   • Aebi et al. (1991)
   • Forman et al. (2009)

   Updated Oct 2026

2. Day 15–56Clinical

   The skin-tone side

   For a brighter tone, glutathione nudges pigment cells from dark eumelanin toward lighter pheomelanin. Swallowed, it lightened skin modestly in a small 4-week trial; for injections, reviews find the evidence too thin to call. Commonly reported: a brighter, more even tone for some over several weeks.

   The science

   Arjinpathana 2012: in 60 medical students, oral glutathione 500 mg a day for 4 weeks lowered the melanin index at all six sites measured, significantly more than placebo at two (face and a sun-exposed forearm). The mechanisms are direct and indirect tyrosinase inhibition and a switch from eumelanin to pheomelanin (Sonthalia 2016). A 2026 review of IV glutathione found modest, inconsistent effects in small studies, often confounded by vitamin C given alongside, and judged the evidence too limited for routine cosmetic use (Aloraini 2026).

   Sources

   • Arjinpathana & Asawanonda (2012)
   • Sonthalia et al. (2016)
   • Aloraini et al. (2026)

   Updated Oct 2026

3. Any dayClinical

   What Glutathione is built on

   The biology is textbook: every cell makes glutathione, and it is central to antioxidant defense. The evidence for injecting it is thin: IV pharmacology, a small IV trial and oral trials, with nothing on SubQ or IM use. The best-documented danger is contaminated product, as the 2026 recalls showed.

   The science

   Glutathione is the most abundant low-molecular-weight thiol cells make (Forman 2009); oxidized glutathione is recycled by glutathione reductase at the expense of NADPH (Lu 2013). IV glutathione 1,400 mg three times a week for 4 weeks was well tolerated in a 21-person pilot trial in Parkinson's disease, with no significant benefit (Hauser 2009). Reviews find no good evidence that IV glutathione lightens skin, and the Philippines FDA has warned against that use (Sonthalia 2016). CDC linked over 25 illnesses in at least four states in 2026 to IV, IM and SubQ glutathione compounded from supplement-grade powder, likely contaminated with endotoxin (CDC 2026).

   Sources

   • Forman et al. (2009)
   • Lu (2013)
   • Hauser et al. (2009)
   • Sonthalia et al. (2016)
   • CDC (2026)

   Updated Oct 2026

4. With NAD+Community

   Why glutathione rides with NAD+

   A common pairing: NAD+ for the energy side and glutathione for the antioxidant side. The biochemistry links them: cells recycle used glutathione with NADPH, which they make from NAD+. No study has tested the two together.

   The science

   Oxidized glutathione (GSSG) is reduced back to GSH by glutathione reductase at the expense of NADPH, forming a redox cycle (Lu 2013); NADP+, the oxidized form of NADPH, is made from NAD+ by NAD kinase (Oka 2023). That shared chemistry is the rationale for the stack; the combination itself is untested.

   Sources

   • Lu (2013)
   • Oka et al. (2023)

   Updated Oct 2026

5. With GHK-Cu, BPC-157 and TB-500Community

   Glutathione in a glow protocol

   In "glow" protocols glutathione runs beside the GLOW blend: GHK-Cu for skin quality, glutathione for tone. The pairing comes from community practice; no study has tested them together. Commonly reported: a brighter look over weeks for some.

   The science

   Glutathione's skin rationale is tyrosinase inhibition and a shift toward pheomelanin (Sonthalia 2016); GHK-Cu's is collagen support, from cell and topical studies (see its entry). Each has only small or indirect human data for skin, and no study has combined them.

   Sources

   • Sonthalia et al. (2016)

   Updated Oct 2026

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After week 8

1. Day 57–120RCT

   Building the body's own supply

   Over months, what moves is the body's store: in a 6-month trial, daily oral glutathione raised blood levels by 30–35% at the higher dose, and they returned to baseline a month after stopping. No study has measured this with injections.

   The science

   Richie 2015 (54 non-smoking adults, oral 250 or 1,000 mg a day for 6 months): glutathione rose 30–35% in red cells, plasma and lymphocytes at 1,000 mg, and 17% (whole blood) and 29% (red cells) at 250 mg; natural killer cell activity more than doubled at 3 months on 1,000 mg; levels returned to baseline after a 1-month washout. A single 3 g oral dose raised nothing in plasma (Witschi 1992), so the gains came with daily, long-term use.

   Sources

   • Richie et al. (2015)
   • Witschi et al. (1992)

   Updated Oct 2026

A typical run.

Safety.

Goes with.

• NAD+
• GLOW

Questions people ask.

Research.

Reference.

Cadence

Daily

Daily or EOD

Half-life

~14 min

~14 min (measured in people after an IV infusion; never measured after SubQ or IM injection)

Research basis

●●● Emerging

Primarily preclinical / limited human data