Glutathione is the main antioxidant your body makes inside its own cells. It's a small protein (three amino acids: glutamate, cysteine, glycine) that sits in basically every cell you have, mopping up oxidative damage, recycling other antioxidants like vitamin C and E, and acting as the central tool your liver uses to neutralise toxins, drugs, alcohol, and metabolic waste. Most people who take it to support liver function, to dampen general oxidative stress as they age, or for skin tone and brightness.

The catch is that the form matters more than the dose. Swallowing a capsule of plain glutathione is inefficient because the gut breaks much of it down before it reaches your bloodstream. Liposomal glutathione, sublingual versions, and the precursor approach (NAC plus glycine, often called GlyNAC) all reliably raise body stores. Standard oral glutathione works too at high enough doses and over enough time, but it's the slowest route. Injectable forms (IV and IM) skip the gut entirely but carry real safety baggage and aren't necessary for most goals.

Deep-dive

Dosage:

• Liposomal or micellar oral: 500-1000 mg/day. This is the most efficient practical route. Effects on glutathione stores typically show up within 2-4 weeks. Take on an empty stomach for best absorption. Brands matter, look for actual liposomal encapsulation rather than just the word on the label
• Standard oral (Setria-grade): 250-1000 mg/day. Works but slower, expect 1-3 months for meaningful changes. The 1000 mg dose has the cleaner data
• GlyNAC (precursor approach): 100 mg/kg/day each of glycine and N-acetylcysteine, divided into two doses. For a 70 kg person that's about 7 g of each per day, taken as 3.5 g morning and evening. This is the dose used in the Baylor trials and is most relevant if your goal is the broad anti-aging, mitochondrial, and metabolic angle rather than skin or acute liver support. Cheaper than liposomal glutathione by a wide margin
• Skin brightening protocol: 250-500 mg/day oral glutathione, expect 4-12 weeks before noticing anything. Pairing with vitamin C (500-1000 mg) is common in published protocols and may modestly enhance the effect. Sun protection is non-negotiable, the brightening only shows up where UV isn't constantly stimulating new melanin production
• Liver support during a heavy period: 500-1000 mg/day liposomal during periods of high alcohol intake, medication load, or known toxin exposure. Consider stacking with NAC at 600 mg twice daily
• Older adults (60+): Both glutathione status and glutathione synthesis decline with age, and this group tends to respond well. The GlyNAC approach has the strongest evidence here. If using oral glutathione, run the higher end of doses (1000 mg liposomal)
• Women in perimenopause and menopause: Same dosing as the general adult range, but this is a group where the underlying glutathione deficit is often more pronounced and benefits may be more noticeable. No specific dose adjustment needed
• Forms that don't work well: S-acetyl glutathione is marketed as superior but pharmacokinetic data suggests it gets deacetylated rapidly and ends up indistinguishable from plain glutathione. Sublingual lozenges work reasonably well via oral mucosa absorption. Nebulised glutathione should be avoided unless you're working with a clinician for a specific lung condition (see side effects)
• IV glutathione: 600-2400 mg per session, typically administered weekly or bi-weekly in clinical settings. Only worth considering for specific medical indications, not for general wellness. Sterile compounding and proper medical oversight are mandatory
• IM glutathione: 600-1200 mg per injection, typical aesthetic clinic protocols run twice weekly for 4-12 weeks then drop to weekly or bi-weekly maintenance. Often paired with vitamin C 500-1000 mg either in the same syringe (if compounded together) or as a separate injection. Z-track or deep IM into the gluteal or deltoid muscle. The skin-brightening protocols circulating online are not trial-validated, expectations should match the modest effects seen in oral skin trials. The Lenzi infertility protocol of 600 mg every other day for 2 months is the only peer-reviewed IM dosing schedule for any non-skin indication. If you're going to use IM, source from a reputable compounding pharmacy with verifiable sterility documentation, not generic kits sold online. Avoid injecting product not labelled and intended for parenteral use, oral powders are not sterile and using them for injection is how serious infections happen

Here's what you can expect:

For most goals, glutathione is a slow-burn supplement, not something you feel from a single dose. Within 2-4 weeks of consistent liposomal use you may notice slightly clearer skin, less morning grogginess after drinking, and faster recovery from heavy days. The effects are subtle and easy to miss if you're not paying attention, which is why people often abandon it before it's had time to work.

For skin brightening specifically, the timeline is 4-12 weeks for visible changes, and only at sun-exposed sites. Don't expect dramatic depigmentation, expect a modest evening of tone and a slight overall brightness. The effect reverses within weeks of stopping, so it's a maintenance compound rather than a one-time intervention.

For liver support during heavy alcohol periods or medication courses, the subjective signal is usually "hangovers feel less brutal" and "I bounce back faster." Bloodwork (ALT, AST, GGT) is the more reliable signal if you actually want to verify it's doing something.