Comparison
GHK-Cu vs Glutathione
Side-by-side of GHK-Cu and Glutathione. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
GHK-Cu
GHK-Cu peptide (glycyl-L-histidyl-L-lysine copper) is a topical copper peptide. Trials show fine-line and wound-healing gains; injectable longevity claims rem.
Glutathione
Glutathione (GSH) is the body's primary intracellular antioxidant. Oral supplementation has variable bioavailability; sublingual, liposomal, and IV forms.
Effects at a glance
GHK-Cu
- •Endogenous tripeptide that binds copper(II); plasma levels decline ~60% from age 20 to 60
- •Topical RCTs show improvement in skin firmness, fine lines, and barrier function over 12 weeks
- •Wound-healing models report accelerated re-epithelialization in diabetic and aged skin
- •Pickart gene-expression analyses show reset of >4000 genes toward a younger expression profile in cell culture
- •Anecdotal subcutaneous longevity protocols use 1 to 3 mg daily; no human longevity RCTs exist
- •Hair-growth claims rest on small open-label trials and topical scalp formulations
Glutathione
- •Body's primary intracellular antioxidant; tripeptide of glutamate, cysteine, glycine
- •Oral bioavailability poor; sublingual, liposomal, IV more reliable
- •Richie 2014 trial showed body GSH store increases at 250-1000 mg/day for 6 months
- •NAC supplementation often more cost-effective indirect strategy
- •Modest signals in NAFLD, skin aging, immune support; weak in cardiovascular
Side-by-side
| Attribute | GHK-Cu | Glutathione |
|---|---|---|
| Category | peptide | supplement |
| Also known as | Copper Peptide, Glycyl-L-histidyl-L-lysine copper, GHK | GSH, L-glutathione, reduced glutathione |
| Half-life (hr) ↗ | 0.5 | 0.5 |
| Typical dose (mg) ↗ | 2 | 500 |
| Dosing frequency | daily | daily, often divided |
| Routes | topical, subcutaneous | oral, sublingual, intravenous |
| Onset (hr) | 24 | 1 |
| Peak (hr) | 168 | 2 |
| Molecular weight | 340.85 | 307.32 |
| Molecular formula | C14H24N6O4 (GHK alone); C14H22CuN6O4 with Cu(II) | C10H17N3O6S |
| Mechanism | Tripeptide that chelates Cu(II) and delivers it to copper-dependent enzymes (lysyl oxidase, superoxide dismutase). Modulates expression of >4000 genes toward a younger profile in fibroblast culture, including upregulation of decorin and downregulation of pro-inflammatory cytokines. | Tripeptide antioxidant; substrate for glutathione peroxidase (H2O2 reduction), GST (xenobiotic conjugation), glutaredoxin (redox signaling). GSH:GSSG ratio is the central cellular redox indicator. |
| Legal status | Topical cosmetics legal in most jurisdictions; injectable form not FDA approved for any indication; research-use-only grey market | OTC dietary supplement |
| WADA status | allowed | allowed |
| DEA / Rx | Topical OTC (cosmetic); injectable not FDA approved; research-chemical status | OTC supplement |
| Pregnancy | Insufficient data; topical use likely low-risk; injectable not recommended | Insufficient data at supplemental doses; endogenous compound is safe |
| CAS | 49557-75-7 | 70-18-8 |
| PubChem CID | 73587 | 124886 |
| Wikidata | Q3104638 | Q116907 |
Safety profile
GHK-Cu
Common side effects
- mild erythema at topical site
- transient itch
- blue-green discoloration of injection site (copper)
- rare contact dermatitis
Contraindications
- copper allergy
- Wilson disease
- open wound near injection site (caution)
- pregnancy (no data)
Interactions
- topical retinoids: additive irritation; alternate days or apply at different times(minor)
- topical vitamin C (ascorbic acid): ascorbate reduces Cu(II) to Cu(I), which can destabilize the GHK-Cu complex; separate by 30 minutes(minor)
Glutathione
Common side effects
- mild GI upset
Contraindications
- asthma (IV / inhaled forms specifically)
- active chemotherapy without oncologist guidance
Interactions
- chemotherapy agents: theoretical interference with GSH-depletion-dependent agents(moderate)
Which Should You Take?
Glutathione comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-B outcome catalogued. GHK-Cu is the right call when one of the conditionals below applies.
- → If your priority is skin health, pick GHK-Cu.
- → If your priority is wound healing, pick GHK-Cu.
- → If your priority is liver function, pick Glutathione.
- → If your priority is immune support, pick Glutathione.
Edge case: If you want to avoid research-only / gray-market sourcing, Glutathione is the more accessible choice.
Default choice: Glutathione. Lower friction to source, and broader goal coverage. Reach for GHK-Cu only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between GHK-Cu and Glutathione?
GHK-Cu and Glutathione differ in category (peptide vs supplement), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, GHK-Cu or Glutathione?
GHK-Cu half-life is 0.5 hours; Glutathione half-life is 0.5 hours.
Can you stack GHK-Cu with Glutathione?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper