Three amino acids and a copper ion.

GHK-Cu. First described in human plasma, 1973. Studied for five decades.

Your skin doesn't need instructions. It needs the signal.

gly · his · lys · cu²⁺

03 · the serum

Blue by chemistry, not by dye.

A copper tripeptide in a base that stays out of the way. No fragrance. Water-light, glass-smooth. Two drops, morning and night. Press in. Let it settle.

A single drop of blue serum frozen in a crown splash — one drop · 1/8000 s

Glass dropper holding a suspended drop above the open bottle — one drop · held

A luminous drop of serum resting on skin — on skin · press in

The SIGNAL dropper bottle: frosted grey glass, blue serum, copper collar

04 · the bottle

Frosted glass. Copper collar. A dropper that measures, not pours.

ghk-cu 3.0%
30 ml
fragrance-free
ph 5.5
vegan
batch № 001

Notify me at launch

05 · the waitlist

The first batch is small.

The list gets first pour. Small batch, in order.

first batch ships late 2026

one email when it's live · nothing else · never shared

SIGNAL

Three amino acids and a copper ion.

Blue by chemistry, not by dye.

Frosted glass. Copper collar. A dropper that measures, not pours.

The first batch is small.