Comparison
GHK-Cu vs Tirzepatide
Side-by-side of GHK-Cu and Tirzepatide. 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.
Tirzepatide
Tirzepatide for weight loss: dual GIP/GLP-1 agonist sold as Mounjaro and Zepbound. SURMOUNT-1 showed 22.5% mean body-weight loss at 15 mg over 72 weeks.
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
Tirzepatide
- •Dual GIP plus GLP-1 receptor agonist with a ~5-day half-life supporting once-weekly subcutaneous dosing
- •SURMOUNT-1 reported ~22.5% mean body-weight loss at 15 mg over 72 weeks versus 2.4% on placebo
- •Lowers HbA1c by ~1.9 to 2.6 percentage points in type 2 diabetes across SURPASS trials
- •Outperformed semaglutide 1.0 mg head-to-head on weight loss and HbA1c in SURPASS-2
- •GI effects (nausea, diarrhea, vomiting) drive most discontinuations and ease with slow titration
- •Lean-mass loss observed in body-composition substudies; resistance training and protein intake mitigate this
Side-by-side
| Attribute | GHK-Cu | Tirzepatide |
|---|---|---|
| Category | peptide | pharmaceutical |
| Also known as | Copper Peptide, Glycyl-L-histidyl-L-lysine copper, GHK | Mounjaro, Zepbound, LY3298176 |
| Half-life (hr) ↗ | 0.5 | 120 |
| Typical dose (mg) ↗ | 2 | 10 |
| Dosing frequency | daily | weekly |
| Routes | topical, subcutaneous | subcutaneous |
| Onset (hr) | 24 | 24 |
| Peak (hr) | 168 | 72 |
| Molecular weight | 340.85 | 4813.45 |
| Molecular formula | C14H24N6O4 (GHK alone); C14H22CuN6O4 with Cu(II) | C225H348N48O68 |
| 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. | Synthetic 39-amino-acid peptide that activates both GIP and GLP-1 receptors. Potentiates glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and acts on hypothalamic and brainstem satiety circuits. |
| Legal status | Topical cosmetics legal in most jurisdictions; injectable form not FDA approved for any indication; research-use-only grey market | Prescription only; FDA-approved 2022 (T2DM, Mounjaro) and 2023 (chronic weight management, Zepbound) |
| WADA status | allowed | allowed |
| DEA / Rx | Topical OTC (cosmetic); injectable not FDA approved; research-chemical status | Rx only (not a controlled substance) |
| Pregnancy | Insufficient data; topical use likely low-risk; injectable not recommended | Not recommended; discontinue 2 months before planned pregnancy |
| CAS | 49557-75-7 | 2023788-19-2 |
| PubChem CID | 73587 | 156588324 |
| Wikidata | Q3104638 | Q105099794 |
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)
Tirzepatide
Common side effects
- nausea
- diarrhea
- vomiting
- constipation
- decreased appetite
- injection-site reactions
- fatigue
- abdominal pain
Contraindications
- personal or family history of medullary thyroid carcinoma
- multiple endocrine neoplasia type 2
- pregnancy
- history of pancreatitis (use caution)
- severe gastroparesis
Interactions
- insulin: additive hypoglycemia risk; insulin dose typically reduced(major)
- sulfonylureas (glipizide, glyburide): hypoglycemia risk, sulfonylurea dose often reduced(major)
- oral medications (general): delayed gastric emptying can alter absorption kinetics(moderate)
- oral contraceptives: reduced exposure after first dose; backup contraception recommended for 4 weeks after initiation and each dose escalation(moderate)
- warfarin: monitor INR due to altered absorption(moderate)
Which Should You Take?
Tirzepatide comes out ahead for most readers on the criteria we weight: 3 catalogued goals, prescription-only, 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 metabolic health and glucose control, pick Tirzepatide.
- → If your priority is fat loss, pick Tirzepatide.
Edge case: Half-lives differ materially (GHK-Cu ~0.5 hr vs Tirzepatide ~120 hr). Tirzepatide reaches steady state faster; GHK-Cu is easier to dial in if tolerability is uncertain.
Default choice: Tirzepatide. Wider use case, 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 Tirzepatide?
GHK-Cu and Tirzepatide differ in category (peptide vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, GHK-Cu or Tirzepatide?
GHK-Cu half-life is 0.5 hours; Tirzepatide half-life is 120 hours.
Can you stack GHK-Cu with Tirzepatide?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper