Comparison
GHK-Cu vs Nicotinamide Riboside
Side-by-side of GHK-Cu and Nicotinamide Riboside. 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.
Nicotinamide Riboside
Nicotinamide riboside (NR) is the most-studied NAD+ precursor in humans. Sold as Niagen by Chromadex; raises plasma NAD+ 30-60% at 250-1,000 mg/day.
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
Nicotinamide Riboside
- •Most-studied NAD+ precursor in human trials; the original Niagen formulation by Chromadex
- •Plasma NAD+ rises 30-60% at 250-1,000 mg/day across multiple human PK trials
- •Martens 2018 reported reduced BP and arterial stiffness at 500 mg/day for 6 weeks
- •Dollerup 2018 found no insulin sensitivity change despite plasma NAD+ rise
- •Tissue NAD+ rise inconsistent; hard clinical endpoints not yet measured
- •Larger human safety database than NMN; comparable mechanistic effects
Side-by-side
| Attribute | GHK-Cu | Nicotinamide Riboside |
|---|---|---|
| Category | peptide | supplement |
| Also known as | Copper Peptide, Glycyl-L-histidyl-L-lysine copper, GHK | NR, Niagen, nicotinamide riboside chloride |
| Half-life (hr) ↗ | 0.5 | 8 |
| Typical dose (mg) ↗ | 2 | 500 |
| Dosing frequency | daily | daily, typically morning |
| Routes | topical, subcutaneous | oral |
| Onset (hr) | 24 | 1 |
| Peak (hr) | 168 | 4 |
| Molecular weight | 340.85 | 255.25 |
| Molecular formula | C14H24N6O4 (GHK alone); C14H22CuN6O4 with Cu(II) | C11H15N2O5 |
| 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. | NAD+ precursor via salvage pathway. Phosphorylated to NMN by nicotinamide riboside kinase (NRK), then converted to NAD+. Substrate for sirtuins, PARPs, and CD38. |
| 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 supplement doses |
| CAS | 49557-75-7 | 1341-23-7 |
| PubChem CID | 73587 | 439924 |
| Wikidata | Q3104638 | Q3343054 |
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)
Nicotinamide Riboside
Common side effects
- mild GI upset (rare)
- headache (rare)
Contraindications
- pregnancy / lactation (insufficient data)
- active cancer (theoretical, no contraindicating data)
Interactions
- pterostilbene: complementary sirtuin pathway (Basis combination)(minor)
- TMG (trimethylglycine): methylation support during high NAD+ precursor dosing(minor)
Which Should You Take?
Nicotinamide Riboside comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-A 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 energy and stamina, pick Nicotinamide Riboside.
- → If your priority is metabolic health and glucose control, pick Nicotinamide Riboside.
Edge case: If you want to avoid research-only / gray-market sourcing, Nicotinamide Riboside is the more accessible choice.
Default choice: Nicotinamide Riboside. Lower friction to source, a Tier-A evidence outcome catalogued, 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 Nicotinamide Riboside?
GHK-Cu and Nicotinamide Riboside 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 Nicotinamide Riboside?
GHK-Cu half-life is 0.5 hours; Nicotinamide Riboside half-life is 8 hours.
Can you stack GHK-Cu with Nicotinamide Riboside?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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