Step 03 · EveningRecover + RenewGHK-CuMethylene Blue

Recover + Renew

GHK-Cu Firming Serum

GHK-Cu paired with methylene blue for overnight antioxidant support, for a firmer, more vibrant-looking complexion by morning.

★★★★★ 5.0 · 6 verified reviews
$144 59 ml / 2 oz.
  • GHK-Cu at effective concentration for overnight renewal
  • Methylene blue, published in Nature Scientific Reports
  • Works during your skin's natural overnight repair window
  • The texture change most people notice by week two
Made in the USAGHK-Cu core peptideZero filler ingredients
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Reviews

What customers notice after a few weeks on the protocol.

★★★★★

I've been using CKYN for about 2 months and the results are legit. My skin is firmer, brighter, and smoother. Forehead wrinkles are disappearing and dark under-eye circles are 100% gone. The deep moisturizing effect of the lotion and balm has been a game changer for me in the dry mountain climate of Colorado. This is one of those products that will become a staple in my routine for years to come. Results are incredible.

Jared E. · Verified Buyer · Dry skin · 8 weeks
★★★★★

Six weeks in. My skin actually holds moisture now, which after years of Colorado winters I'd sort of given up on. Cheeks are smoother. A friend asked what I was doing differently, which was nice. If I had to pick one I'd keep the tallow balm, but I'm using all three.

Emily E. · Verified Buyer · Dry skin · 6 weeks
★★★★★

My skin reacts to everything so I started with just the lotion for two weeks before adding anything else. No reaction. That alone is unusual for me. Around week 3 the redness had calmed down and my skin looked smooth and less irritated in general. I really like what I'm seeing.

Tracy H. · Verified Buyer · Sensitive skin · 6 weeks
★★★★★

I was using five things before this and I've cut down to these three, which honestly I thought would be a downgrade. It wasn't. By about week five my skin looked brighter and more even, mostly through the cheeks. The morning lotion absorbs fast and doesn't pill under makeup, which was my main worry going in because the last serum I tried was a disaster under foundation. Fewer products, better skin. I'll take it.

Heather K. · Verified Buyer · Combination skin · 5 weeks
★★★★★

The tallow balm is what got my attention. I've been trying to simplify my ingredients for a couple of years and usually you pick between a product that works and a product you feel good about. Somewhere around week seven I noticed my skin wasn't feeling tight by the afternoon anymore. Tone looks more even too.

Kali J. · Verified Buyer · Normal to dry skin · 7 weeks
★★★★★

Wife bought it. I used it. Face looks less tired and the forehead lines aren't as deep. Using it after I shave, and my skin looks clearer by the week. Reordered.

Chad M. · Verified Buyer · Normal skin · 8 weeks

Nighttime is when your skin renews.

Overnight renewal

Supports the look of your skin's overnight recovery with GHK-Cu and cellular antioxidant support while you sleep.

Firmer by morning

GHK-Cu and methylene blue together are associated with a firmer, more vibrant-looking complexion on waking.

Bright, rested look

Methylene blue works beyond surface-level antioxidant activity, contributing to a more vibrant, even-toned appearance.

Fewer ingredients. Higher concentration.

The Firming Serum pairs GHK-Cu with methylene blue for overnight antioxidant support during your skin's renewal window. Every ingredient earns its place.

Cu GHK-Cu · Copper Peptide The foundational active, at effective concentration

Glycyl-L-histidyl-L-lysine copper(II), molecular weight 340.38 Da, first identified in human plasma in 1973. We deliver it back at concentrations designed to produce visibly firmer, smoother, more refined-looking skin overnight.

Randomized, double-blind trial. Published studies associate GHK-Cu with a marked reduction in the appearance of wrinkle volume over 8 weeks, outperforming vitamin C and retinoic acid comparators in firmness trials.
Pickart et al., PMC 2018 · pmc.ncbi.nlm.nih.gov/articles/PMC6073405/
MB Methylene Blue · Cellular Antioxidant Works during your skin's overnight repair window

A potent antioxidant that works at the cellular level during your skin's overnight repair window. The visible result is a firmer, more vibrant-looking complexion by morning.

Published in Nature Scientific Reports. Studied for its antioxidant properties in laboratory skin models, where it outperformed vitamin C and vitamin E in fibroblast proliferation.
Xiong Z.M., et al. (2017). Scientific Reports 7:2475. · www.nature.com/articles/s41598-017-02419-3
MH Manuka Honey · Overnight Hydration A humectant for a plump, dewy morning finish

New Zealand-sourced manuka honey with unique methylglyoxal compounds, contributing to a visibly hydrated, supple-looking complexion by morning.

Human appearance study. A 2025 study of 40 women using a manuka-based serum for 8 weeks reported improvements in the appearance of fine lines, dark spots, and dryness.
O'Gorman E., et al. (2025). Cureus 17(3):e81244.

Ingredient statements describe appearance outcomes only and are supported by published research. They are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary.

Your skin runs on science.

GHK-Cu is a copper tripeptide found naturally in human plasma. Levels peak in your 20s and decline from there. Over forty years of published research make it one of the most studied compounds in cosmetic peptide science.

55.8%

reduction in the appearance of wrinkle volume in a randomized, double-blind trial over 8 weeks

Pickart et al., PMC 2018
70%

of volunteers showed visibly improved skin firmness, outperforming vitamin C and retinoic acid comparators

Pickart et al., multiple publications
32.8%

reduction in the visible appearance of wrinkle depth (double-blind, 8 weeks)

Published cosmetic science research
40+

years of published research since GHK-Cu was first identified in human plasma in 1973

Discovered by Dr. Loren Pickart

All figures from published, peer-reviewed cosmetic science research. These statements refer to the ingredient GHK-Cu as studied in published literature and are not claims about CKYN products specifically. Individual results vary.

The right dose, not the highest dose.

Published dose-response research indicates GHK-Cu is active at nanomolar concentrations. CKYN formulates to that data and delivers it through the formula, not to a shelf headline.

Brand / ProductGHK-Cu DosePrice / ozAssessment
The Ordinary Multi-Peptide + Copper 1% ~1% blend $18/oz Underdosed effective GHK-Cu; entry-level positioning
NIOD CAIS 3 (Deciem) 1% dual complex $124/oz Sophisticated chemistry; still above the nanomolar optimum
Skin Biology 3% VIP Serum 3% $71/oz Founder-brand; no published evidence 3% outperforms optimally-dosed formulas
Vitali 3% GHK-Cu Serum 3% $89/oz Aggressive high-dose; approaches cytotoxicity thresholds in some cell models
CKYN Firming SerumThis product Effective concentration ~$72/oz Calibrated to the studied range; paired with methylene blue for overnight support

Competitor data compiled from the CKYN Ingredient Science Brief. Verify current pricing and formulations before publishing comparison claims.

Where it fits in your protocol

Your skin rewards consistency. This is one of three daily application windows.

01

Cleanse for the night

Remove the day. Apply to clean, dry skin before bed.

02

Apply the serum

Press several drops over face and neck. Let it absorb fully.

03

Let it work overnight

The serum supports overnight renewal. Wake to a firmer, more refreshed-looking complexion.

What goes into every bottle. And what stays out.

40+ Years of Research

GHK-Cu has been studied in peer-reviewed cosmetic science since 1973. This is not a trending ingredient.

Intentional Ingredients

No filler ingredients, no added fragrance, no label padding. Every ingredient earns its place, backed by published research.

Cruelty-Free

No animal testing at any stage of development or production.

Made in the USA

Formulated and manufactured domestically.

Clinical-Grade Concentrations

GHK-Cu at levels designed to produce visible change. Not trace amounts added for label claims.

Biocompatible by Design

Grass-fed tallow mirrors your skin's own lipid structure. GHK-Cu is a peptide your body already recognizes.

Before you decide.

What makes this serum different?

It pairs GHK-Cu with methylene blue, a cellular antioxidant that works during your skin's overnight repair window, for a firmer, more vibrant-looking complexion by morning, rather than a single-active serum.

How does this compare to retinol or vitamin C?

Retinol and vitamin C are effective but come with trade-offs: irritation, sun sensitivity, oxidation. GHK-Cu is naturally biocompatible, does not cause photosensitivity, and supports a visibly improved complexion without the adjustment period most actives require. Published studies show GHK-Cu outperformed both retinol and vitamin C comparators in visible firmness trials.

When will I see results?

Most people notice a hydration and texture difference within the first two weeks. Visible improvements in firmness and fine lines typically appear between weeks four and eight with consistent use.

Can I use it with other actives?

Copper peptides are often used in a separate step from strong acids or vitamin C. If you use those, consider reserving the Firming Serum for night. When in doubt, ask your dermatologist.

Morning prepares. Daytime defends. Nighttime renews.

Each product amplifies the next. The protocol creates compound results that no single product, at any price, can match.

The Complete CKYN Protocol

Your skin absorbs what it can in each application. Three doses a day compounds what a single product cannot. Morning, daytime, and night in one system.

$399
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The three CKYN products together — Perfecting Lotion, Tallow Balm, and Firming Serum
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