The Optimal Health Manifesto
Peptide profile

GHK

BAnimal-grade 🟢Green See the side-effect detail ↓
What do these badges mean?

Evidence tier

  • AHuman-validated — Human trials showing positive results and good safety.
  • BAnimal-grade — No human trials yet, but solid animal/preclinical evidence of effect and safety.
  • CAnecdotal — No human or animal trials — only anecdotal/observational reports.
  • DInsufficient evidence — No or insufficient evidence (encyclopedia only — never recommended by the builder).

Safety light

  • 🟢 Green — Only mild, manageable side effects; reasonable safety data.
  • 🟡 Yellow — Needs active management, has a meaningful contraindication/interaction, or has thin long-term data.
  • 🔴 Red — Risk of a hospital-level event — treat with serious caution.

Browse-only — not on the protocol builder's curated shortlist, so the builder won't recommend it.

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Question 1

What is it?

GHK is the non-copper-coordinated form of the GHK tripeptide (Gly-His-Lys) — the base molecule behind GHK-Cu, the copper-bound compound that anchors the whole copper-peptide family in this cluster (alongside Pal-GHK, AHK-Cu, and Pal-AHK).

Question 2

What does it do in my body?

GHK modulates gene expression related to tissue remodeling, collagen synthesis, and wound healing.

Question 3

How can it help me?

  • Where the science stands: Moderate — 30 studies including human and animal (the strongest evidence base in the cosmetic-topical cluster); OHM grades it Tier B by extrapolation from the GHK-Cu literature

The full evidence — every human, animal, and lab study, graded — is one tap away: use the See the deeper science → toggle at the top.

Question 4 & 5

Is it dangerous? What are the side effects?

No adverse-effect data specific to the free-base (non-copper) form was captured in the source profile beyond what’s documented for the copper-bound compound. See GHK-Cu for the detailed safety and side-effect picture, which largely applies to this parent molecule.

Regulatory status: The source material does not distinguish a separate regulatory status for free-base GHK from the copper-bound form. See GHK-Cu for the full regulatory picture (topical = legal OTC cosmetic; injectable = research-use-only, with an evolving FDA compounding-list status).

Dosing

Typical dosing

Talk to your medical provider before starting any protocol. That said, here are the doses most people commonly use — shared for educational purposes so you can have an informed conversation. These peptides are sold for research use only and are not FDA-approved drugs, and this isn't medical advice.

The source material for free-base GHK does not carry its own distinct dosing protocol separate from the copper-bound compound; OHM’s copper-family framing treats GHK-Cu as the practical, commercially relevant form (topical or injectable). No standalone free-base GHK protocol was captured in the source.

Question 7 & 8

What should I avoid combining — and what's synergistic?

GHK doesn't have a dedicated stacking protocol in our notes — the interactions that matter most are in the safety section above. For how people combine it with other peptides, the deeper-science view has the full detail.

Question 9

How can I buy this?

We don't have a verified affiliate source for GHK yet, so there's no coupon or vendor link here — we won't point you to a seller we haven't vetted. When buying any research-use-only peptide, the single biggest variable is the supply chain: insist on a vendor that publishes third-party Certificates of Analysis (COAs) confirming identity and >99% purity. Working with a peptide-literate clinician is one solid route — see our provider directory — or check back as our verified sources list grows.

Sources & references

  • (thepeptidelist.com directory, captured 2026-06-07) — profile grade: Moderate, 30 studies, human + animal. Studies cited: Byun et al., 2016, PMID 27064823; PMID 36905132; PMID 28370978.
  • OHM tier/safety grading: Tier B / green / recommend-eligible ( + SECONDARY heal-recover), by extrapolation from the GHK-Cu literature.
  • Migrated from cosmetic-topical-peptides-cluster.md (2026-06-10 cluster build) as part of the cluster-to-standalone-article migration.

Related: GHK-Cu · Pal-GHK · AHK-Cu · Pal-AHK · GLOW

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