Compare · Head-to-head
GHK-Cu vs MK-677.
Evidence, risk, regulatory flags, cost, and vendor coverage compared side by side. We don’t sell peptides — we help you choose between them.
Which should you research first?
Start with GHK-Cu, then use the table to confirm fit.
GHK-Cu is the cleaner first read based on the current evidence, risk, and regulatory data stored for this pair. The right answer can still change if your goal, sport testing status, vendor constraints, or monitoring tolerance makes the other option a better fit.
Comparison next step
Personalize this head-to-head.
Take the quiz before converting a comparison into a compound, vendor, or protocol decision.
01 · At a glance
| Decision factor | GHK-Cu | MK-677 |
|---|---|---|
| Primary fit | tissue repair & recovery and longevity & anti-aging comparisons | muscle growth & strength and longevity & anti-aging comparisons |
| Evidence | Tier B-C | Tier C |
| Risk | med-high | med-high |
| Experience level | beginner | advanced |
| Budget tier | budget | mid |
| Administration route | topical | oral |
02 · Use case & timing
| Decision factor | GHK-Cu | MK-677 |
|---|---|---|
| Goal fit | Tissue Repair & Recovery, Longevity & Anti-Aging, Skin & Hair | Muscle Growth & Strength, Longevity & Anti-Aging, GH Axis Optimization |
| What users compare it for | Skin repair, collagen stimulation, wound healing support (topical evidence). | Increased GH/IGF-1 signaling, appetite rise, and potential lean-mass increase in some human studies. |
| Onset timeline | Skin remodeling: weeks to months (collagen turnover cycles). | GH rises acutely; IGF-1 and body-composition effects are tracked over weeks to months. |
| Main tradeoff | Evidence and product availability can still be uneven, so documentation matters more than hype. | Evidence and product availability can still be uneven, so documentation matters more than hype. |
03 · Safety & restrictions
| Decision factor | GHK-Cu | MK-677 |
|---|---|---|
| Adverse effects | Generally better tolerated topically than systemic peptides. | Edema, increased appetite, insulin resistance, elevated fasting glucose, joint discomfort, and possible cardiovascular safety concerns. |
| Contraindications | Copper sensitivity. | Use caution in diabetes, insulin resistance, edema-prone states, heart failure risk, and active malignancy. |
| Interaction notes | Unknown clinically; avoid stacking claims. | Combining with other GH-axis compounds increases endocrine complexity and may worsen glucose control. |
| Regulatory status | Not approved | Not approved |
| FDA flag | No current flag noted | FDA compounding caution |
| WADA status | Not listed | WADA S2 |
04 · Age & monitoring
| Decision factor | GHK-Cu | MK-677 |
|---|---|---|
| Supported age ranges | 25-34, 35-44, 45-54, 55-64, 65+ | 25-34, 35-44, 45-54 |
| Life-stage note | Broad adult fit for cosmetic and skin-repair goals, especially when route is topical rather than systemic. | Most often discussed for younger and midlife adults, but metabolic and fluid-retention risks narrow the fit quickly with age. |
| Monitoring burden | Not specified | high |
| Follow-up cadence | Not yet documented | More frequent early follow-up, then reassessment every few months if continued. |
05 · Cost & sourcing
| Decision factor | GHK-Cu | MK-677 |
|---|---|---|
| Typical cycle cost | $60.00 | No reliable estimate yet |
| Estimated monthly cost | $60.00 | No reliable estimate yet |
| Cost confidence | High confidence | No estimate |
06 · Before you buy
| Decision factor | GHK-Cu | MK-677 |
|---|---|---|
| Tracked vendor listings | 3 listings | 0 listings |
| Sourcing note | Product format varies by listing, so double-check route, concentration, and presentation. | No tracked product page yet, so sourcing takes more manual review. |
| Stack-friendly? | Usually stack-friendly | Usually stack-friendly |
Sources and review notes
- Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks - U.S. Food and Drug Administration - accessed 2026-05-15
Used for FDA compounding-risk context and peptide safety flags.
- The Prohibited List - World Anti-Doping Agency - accessed 2026-05-15
Used for athlete-facing WADA risk and peptide-class restrictions.
- Peptide therapeutics: current status and future directions - PubMed / Nature Reviews Drug Discovery - accessed 2026-05-15
Used for broad peptide-therapeutics background and evidence framing.
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