An oligopeptide is a short chain of amino acids — typically between two and twenty residues long. The prefix oligo- comes from the Greek for “few,” distinguishing these short peptides from longer polypeptide chains and full proteins.

In haircare, oligopeptides are valuable for one specific reason: they are small enough to slip past the cuticle and into the cortex, where damage actually lives. Most conditioning ingredients sit on the surface. Oligopeptides go inside.

Healthy hair is built from keratin — a fibrous structural protein arranged in tightly packed bundles. When hair is damaged by bleach, color, chemical services, or heat, two things break:

1. Polypeptide chains — the long protein backbones that give hair its tensile strength.
2. Disulfide bonds — the cross-links between keratin chains that hold the fiber’s shape.

Repair requires getting inside the cortex to the broken sites. The cuticle layer — overlapping cells that form the outer sheath of the hair shaft — is selective about what it lets through. Large molecules can’t enter. They stay on the surface, providing temporary smoothing, then wash off.

Oligopeptides are small enough to pass the cuticle barrier. Once inside, they bind to broken keratin sites and reinforce the structure from within.

Most peptide haircare brands use a single peptide. Oli G uses two, deployed at different stages of the system to target different damage mechanisms.

SH-Oligopeptide-78

A copper-binding peptide that supports the hair’s natural repair pathways and signals around damaged sites. Found in Atomic Hair Repair Leave-In Treatment — the daily peptide deposit applied to damp hair, every wash. Read more →

Biotinoyl Tripeptide-1

A biotin-conjugated tripeptide (three amino acids) attached to a biotin molecule. Reinforces follicular structure and supports the hair fiber’s mechanical resilience. Found in Atomic, Chemical Addiction, AquaLush, and Renew — four of the seven Oli G products. Read more →

Peptides deposit best into an open cuticle. The cuticle opens at alkaline pH (above 7) and closes at acidic pH (below 7).

Apply a peptide product at neutral or acidic pH and you’ve lost most of the deposit before it can enter the cortex.

This is why Oli G engineers the pH cycle: the Atomic leave-in is deliberately formulated at pH 7.0–8.0 (mildly alkaline) so the cuticle opens and accepts the peptide. The next step — Chemical Addiction Peptide Bonding Spray at pH 3.5–4.6 — closes the cuticle around the deposited peptides, sealing them in.

Most peptide products skip this step. The result: surface adhesion that washes off, not durable cortex repair. Read more about the pH cycle →

• Atomic Hair Repair Leave-In Treatment — SH-Oligopeptide-78 + Biotinoyl Tripeptide-1, the dual peptide deposit
• AquaLush Peptide Fiber Mask — Biotinoyl Tripeptide-1 + Hydrolyzed Keratin, the weekly intensive
• Chemical Addiction Peptide Bonding Spray — Biotinoyl Tripeptide-1, the post-styling seal
• Renew Porosity Balancing Oil — Biotinoyl Tripeptide-1 in an oil format for damp ends