Comparison
GHK-Cu vs Omega-3 (EPA/DHA)
Side-by-side of GHK-Cu and Omega-3 (EPA/DHA). 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.
Omega-3 (EPA/DHA)
Omega 3 fish oil profile: EPA/DHA marine fatty acids, 2-4 g/day cuts triglycerides 20-30%, REDUCE-IT showed 25% cardiovascular risk reduction on icosapent eth.
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
Omega-3 (EPA/DHA)
- •Reduces fasting triglycerides 20-50% at 2-4 g/day in hypertriglyceridemic patients
- •REDUCE-IT showed 25% relative risk reduction in major CV events at 4 g/day icosapent ethyl
- •Modest antidepressant effect (SMD ~0.40) for EPA-dominant formulations at 1-2 g/day
- •Atrial fibrillation incidence rises ~30-50% at 4 g/day; relevant for older patients with pre-existing CV disease
- •Tissue omega-3 index (RBC EPA + DHA) target ~8%; Western baseline typically 4-5%
- •Triglyceride and re-esterified triglyceride forms absorb ~70% better than ethyl esters in fasted state
Side-by-side
| Attribute | GHK-Cu | Omega-3 (EPA/DHA) |
|---|---|---|
| Category | peptide | supplement |
| Also known as | Copper Peptide, Glycyl-L-histidyl-L-lysine copper, GHK | fish oil, EPA, DHA, marine omega-3 |
| Half-life (hr) ↗ | 0.5 | 48 |
| Typical dose (mg) ↗ | 2 | 2000 |
| Dosing frequency | daily | 1 to 2 times daily with food |
| Routes | topical, subcutaneous | oral |
| Onset (hr) | 24 | 4 |
| Peak (hr) | 168 | 12 |
| Molecular weight | 340.85 | 302.45 |
| Molecular formula | C14H24N6O4 (GHK alone); C14H22CuN6O4 with Cu(II) | C20H30O2 (EPA); C22H32O2 (DHA) |
| 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. | Substitutes arachidonic acid in membrane phospholipids, shifting eicosanoid production toward less-inflammatory 3-series prostaglandins and 5-series leukotrienes. Activates PPAR-alpha to lower hepatic VLDL/triglyceride synthesis. DHA modulates synaptic membrane fluidity and neuronal function. |
| Legal status | Topical cosmetics legal in most jurisdictions; injectable form not FDA approved for any indication; research-use-only grey market | Dietary supplement; prescription forms (icosapent ethyl, omega-3 acid ethyl esters) for severe hypertriglyceridemia |
| WADA status | allowed | allowed |
| DEA / Rx | Topical OTC (cosmetic); injectable not FDA approved; research-chemical status | Not scheduled |
| Pregnancy | Insufficient data; topical use likely low-risk; injectable not recommended | Recommended at 200 to 600 mg DHA/day for fetal development |
| CAS | 49557-75-7 | 10417-94-4 |
| PubChem CID | 73587 | 446284 |
| Wikidata | Q3104638 | Q207688 |
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)
Omega-3 (EPA/DHA)
Common side effects
- fishy aftertaste
- eructation (fish burps)
- mild dyspepsia
- loose stools at high doses
Contraindications
- fish allergy (use algal omega-3 alternative)
- active bleeding disorders
- scheduled surgery (discontinue 5-7 days prior)
Interactions
- warfarin and DOACs: additive antiplatelet effect at 2+ g/day; meaningful bleeding risk(moderate)
- aspirin and antiplatelet agents: additive bleeding risk at high doses(moderate)
- statins: complementary cardiovascular effects; no pharmacokinetic interaction(minor)
- antiarrhythmics: high-dose omega-3 increases AF risk; relevant in pre-existing arrhythmia(moderate)
Which Should You Take?
Omega-3 (EPA/DHA) 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 cardiovascular health, pick Omega-3 (EPA/DHA).
- → If your priority is focus or working memory, pick Omega-3 (EPA/DHA).
Edge case: If you want to avoid research-only / gray-market sourcing, Omega-3 (EPA/DHA) is the more accessible choice.
Default choice: Omega-3 (EPA/DHA). 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 Omega-3 (EPA/DHA)?
GHK-Cu and Omega-3 (EPA/DHA) 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 Omega-3 (EPA/DHA)?
GHK-Cu half-life is 0.5 hours; Omega-3 (EPA/DHA) half-life is 48 hours.
Can you stack GHK-Cu with Omega-3 (EPA/DHA)?
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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