The side-by-side guide

GHK-Cu, Glow and KLOW, in perspective.

Use this comparison to sort three names by what they contain, then separate skincare from prescription questions. This is a map of the differences. It does not rank treatments or recommend a peptide.

Licensed U.S. provider review

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Lumira may earn money when readers become Promise patients.

Promise prescribes GHK-Cu, Glow and KLOW now through licensed U.S. providers. A provider reviews every request and decides whether a prescription is appropriate. Not everyone qualifies. Compounded medicines are made to order. They are not approved by the U.S. Food and Drug Administration (FDA).

U.S. patients only. Availability varies by state and by treatment.

Skin peptides, in plain languageGuide date: October 8, 2026Where our facts come from

One ingredient or several?

Read the name before the promise

A peptide is a short chain of amino acids, the building blocks of proteins. A blend is several peptides together. “Glow” and “KLOW” are blend names, not measured skin outcomes. The U.S. Food and Drug Administration (FDA) has not approved any of these as medicines.

GHK-Cu

Contains: GHK, a three-part peptide, bound to copper.
The first question: Which form is being discussed? The cosmetic ingredient Copper Tripeptide-1 is a different context from an injection.
Read the evidence this way: Research includes cells, animals and small human studies of products placed on skin. These do not settle injectable safety.

Go deeper on GHK-Cu

Glow

Contains: GHK-Cu, BPC-157 and TB-500.
The first question: What evidence concerns the mixture itself? Separate ingredient studies cannot answer every question about a blend.
Read the evidence this way: Glow is not an FDA-approved drug. TB-500 is a fragment, or small piece, of thymosin beta-4; evidence about the full peptide is different.

Go deeper on Glow

KLOW

Contains: GHK-Cu, BPC-157, TB-500 and KPV.
The first question: What does the extra ingredient add to the evidence and safety questions? KPV is a three-part peptide made of lysine, proline and valine.
Read the evidence this way: KLOW is not FDA-approved. FDA's KPV review found no information about KPV being given to people. That leaves human safety questions unanswered.

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The form changes the question

A serum and a prescription are different routes

Topical cosmetic

Topical means placed on the skin. Copper Tripeptide-1 appears in cosmetic creams and serums. Most cosmetics do not need approval by the U.S. Food and Drug Administration (FDA) before sale. That does not make their ingredients approved injectable medicines.

Prescription preparation

A prescriber is a licensed health professional who can make prescription decisions. Compounding means preparing a medicine to order. Compounded medicines are not FDA-approved, and a pharmacy must check whether it can lawfully use each ingredient.

A blend still faces ingredient rules

On FDA's page current as of April 22, 2026, BPC-157, TB-500, KPV and injectable GHK-Cu sit in the “nominated but withdrawn” table. The requests for their review were taken back. Withdrawal is not clearance or approval for compounding. FDA gives no withdrawal dates for those entries.

The non-injected GHK-Cu entry is separate. It appears in Category 1 on FDA's list updated May 14, 2026. That means FDA generally does not plan to act against a pharmacy under set conditions while review continues. It is not approval and does not cover injections.

Putting peptides together does not remove these questions. Nor does a product page confirm that a particular prescription is suitable for a person or lawful for a pharmacy to prepare.

Three ways to read any comparison

These distinctions keep the comparison useful without turning early research into a recommendation.

Match the substance. A fragment and a full-length peptide are different.
Match the form. A cream study is not an injection study.
Match the subjects. Lab cells and animals are not people.

Sources for this page

FDA's peptide safety concerns and withdrawn requestsU.S. Food and Drug Administration
FDA's separate category entry for non-injected GHK-CuU.S. Food and Drug Administration · List updated May 14, 2026
How FDA rules for cosmetics differ from drug rulesU.S. Food and Drug Administration
FDA's review of TB-500U.S. Food and Drug Administration · July 2026 briefing
FDA's review of KPVU.S. Food and Drug Administration · July 2026 briefing

The next page is yours

Keep the licensed route in view

A visit begins a review. A licensed U.S. provider decides whether a prescription is appropriate. Not everyone qualifies, and availability varies by state and by treatment.

Licensed U.S. provider review

Start a Promise skin & longevity visit

Lumira may earn money when readers become Promise patients.

Promise prescribes GHK-Cu, Glow and KLOW now through licensed U.S. providers. A provider is a health professional who can make prescription decisions. One reviews every request and decides whether to prescribe. Not everyone qualifies.

Medications are prepared by licensed U.S. compounding pharmacies. Compounded medications are not FDA-approved. A pharmacy separately decides whether it can lawfully prepare a prescription.

U.S. patients only. Availability varies by state and by treatment.

Promise is LegitScript-certified. That certification is not FDA approval.