Two products, two rhythms.
One builds, one resets.
The build
Twice daily, every dayOne pump on clean, damp skin, morning and night. Press in, wait 60 seconds, follow with moisturizer. SPF in the morning, always.
The reset
As needed, 20–30 minutesClean, dry under-eye skin. Daily during stress or travel weeks, or the night before something that matters.
Pause vitamin C. Copper oxidizes ascorbic acid, so used together the two cancel each other out. Put your vitamin C in the morning and the Signal Serum at night, or leave the C out while you’re building.
Everything else layers fine. Niacinamide, hyaluronic acid, peptides, ceramides, retinol, exfoliating acids, SPF — no spacing needed.
What’s actually in it.
Built on 2% GHK-Cu, with four peptides doing the supporting work — two that soften the lines you make when you move your face, two that tell skin to rebuild and stay calm.
2% GHK-Cu
2% GHK-Cu
A copper tripeptide your body makes less of with age. It signals cells to repair, build collagen and elastin, and calm inflammation. Most peptide serums use a trace — 2% is the concentration the research uses.
Copper Tripeptide-1.
Acetyl Hexapeptide-8
Acetyl Hexapeptide-8
Softens the small muscle movements behind crow’s feet and forehead lines. Every smile and squint folds the skin; over time the fold stays. This quiets that movement, so the lines look smoother.
Known as Argireline. Blanes-Mira et al., Int. J. Cosmetic Science, 2002.
Acetyl Octapeptide-3
Acetyl Octapeptide-3
The upgraded version of the one beside it — same mechanism, built a little stronger. Two amino acids longer, so it mimics more of the protein it competes with. Having both doubles down on expression lines.
Manufacturer data, Lipotec.
Palmitoyl Tripeptide-1
Palmitoyl Tripeptide-1
A messenger. It tells skin to rebuild, and supports the structure that keeps it firm. The same core GHK tripeptide as the hero active, without the copper — so it pairs directly with the GHK-Cu.
One half of Matrixyl 3000, Sederma.
Palmitoyl Tetrapeptide-7
Palmitoyl Tetrapeptide-7
This one calms things down. Sun, stress and ordinary life create low-level inflammation that wears skin down over time. Quieting it helps skin hold on to the structure it already has.
The other half of Matrixyl 3000, Sederma.Plus the quiet two. Sodium Hyaluronate pulls water into the upper layers, which is why skin reads plumper inside the first fortnight. Panthenol settles the barrier — the reason this sits well on reactive skin and layers under everything.
What testers saw.
One hundred testers. Eight weeks. Twice a day.
Self-reported on a 10-point scale, measured at day 0 and again at week 8. Individual results vary.
See the full results
Steph’s Glow Up Protocol
Serum, eye patches, red light, microneedling — the exact protocol Steph follows to get her glow.
Get her routineThe quick questions.
What’s in the Duo?
A full-size Signal Serum and a box of GHK-Cu Glow Eye Patches — both launch products, one order, at bundle pricing. You choose 15 or 30 pairs of patches.
Will they arrive together?
No — two shipments, both tracked, both free. The serum ships the week of Nov 9 and the patches the week of Nov 23.
Do I use them at the same time?
They run on different rhythms. The serum is twice daily, every day, and builds over four to eight weeks. The patches are a 20-minute reset you reach for when you need one. Full detail is in How to use above.
What happens when my subscription renews?
Renewals ship the refill version at the refill price, so you aren’t paying for the cobalt tin again. Your first order includes it.
Can I use the serum with my vitamin C?
Not at the same time. Copper oxidizes ascorbic acid, so the two cancel each other out. Put your vitamin C in the morning and the Signal Serum at night. Everything else — niacinamide, hyaluronic acid, retinol, acids, SPF — layers fine.
Is the Duo cheaper than buying separately?
Yes. The Duo is priced below the two products bought on their own, and the subscription takes a further 10% off.
Reviews
After eight weeks: subtle but real. People in my life noticed and commented. I'd buy it again at full price.
Change most visible: looks firmer and less overall redness. i do have a sunspot that got darker but that may not have anything to do with the regimen. People in my life noticed and commented. "Serum is perfection!" I'd buy it again at full price.
After eight weeks: minimal. Change most visible: i don’t notice much of a change. People in my life noticed and commented. "Love the moisturizer and the creaminess"
After eight weeks: subtle but real. Change most visible: my neck and chest. "Serum"
After eight weeks: minimal. Change most visible: i feel like my skin looks better overall. "I love that it's only 2 steps" I'd buy it again at full price.
After eight weeks: clear and visible. Change most visible: i have a glow that people notice. People in my life noticed and commented. "The formula" I'd buy it again at full price.
After eight weeks: subtle but real. Change most visible: skin tone, firmness. I'd buy it again at full price.
After eight weeks: clear and visible. Change most visible: wrinkle reduction on my forehead. I'd buy it again at full price.
After eight weeks: subtle but real. Change most visible: general elasticity. People in my life noticed and commented. I'd buy it again at full price.
After eight weeks: subtle but real. Change most visible: tighter skin, less visible wrinkles. People in my life noticed and commented. "Formula of the serum." I'd buy it again at full price.
After eight weeks: clear and visible. People in my life noticed and commented. "The consistency. It glides on so well. I don’t mind the cream consistency." I'd buy it again at full price.
After eight weeks: clear and visible. Change most visible: the firmness. my skin is thicker but i am also on ghk-cu (third cycle). i would also say the smoothness and elasticity is a lot better. People in my life noticed and commented. "I liked the serum a lot."
After eight weeks: subtle but real. Change most visible: my skin glows more and my lines are less pronounced. People in my life noticed and commented. "The dispenser" I'd buy it again at full price.
After eight weeks: clear and visible. Change most visible: glowy amd more even skin tone. People in my life noticed and commented. "Nothing I love it all" I'd buy it again at full price.
After eight weeks: subtle but real. Change most visible: firmness. "the serum" I'd buy it again at full price.
After eight weeks: subtle but real. Change most visible: i’d say radiance overall on my face. People in my life noticed and commented. "Two step process! Quantities are great too" I'd buy it again at full price.
