Peptide Recommendations for Repairing Damaged Hair and Split Ends (Acetyl Tetrapeptide-3 Efficacy)
Question
I am developing hair care cosmetics and require recommendations for peptides suitable for repairing dry, damaged hair and split ends.
- Is Acetyl Tetrapeptide-3 effective specifically for treating dry, damaged hair and split ends?
- Are there other peptide complexes available that clearly demonstrate efficacy (supported by clinical or in vitro test results) for nourishing and repairing damaged hair/split ends?
Please recommend appropriate peptides for hair care cosmetics, including usage information and supporting test data.
Answer
The efficacy of Acetyl Tetrapeptide-3 is primarily focused on promoting hair growth and strengthening hair follicles, rather than directly repairing existing split ends or severely damaged hair.
- Acetyl Tetrapeptide-3 (Pep®-Brow, ID 35590): Its main mechanism is to stimulate the proliferation of dermal papilla cells, extend the anagen (growth) phase, and improve scalp health through anti-inflammatory properties. While it strengthens the hair structure at the follicle level, for repairing the hair shaft (like split ends), other ingredients are generally more suitable.
- Usage Rate: 1-5%.
For repairing damaged hair and split ends, we recommend peptides and hydrolyzed proteins that can penetrate and reinforce the hair shaft. These ingredients have clear in vitro and in vivo data supporting their structural benefits:
1. Hydrolyzed Keratin/Proteins (For Repair and Strength)
These are polypeptides that can penetrate the hair cuticle, fill in gaps, and restore the hair's structural integrity, which is essential for repairing split ends and damage.
- Pure Keratin™ (ID 657): Derived from Australian Sheep Wool, this polypeptide chain is absorbed into the hair to restore strength, moisture, and shine, making it highly suitable for hair damaged by dyeing, perming, or heat.
- Testing: Known to restore hair condition and make hair peptide binding tighter.
- Usage Rate: 0.5-2.0% (recommended 2.0% for leave-on treatments/masks).
- Hydrolyzed Plant Keratin (Plant-Based Keratin, Liquid) (ID 126155): A plant-derived protein (e.g., pea/wheat) that conditions and reinforces hair fibers.
- Testing: Studies report improved hair feel, hydration, combing, and reduced breakage due to film-forming peptides and penetrating low-molecular-weight fractions.
- Usage Rate: 0.5-5% (typical 2-3%).
2. Peptides for Follicle Health and Growth
These are excellent for overall hair density and strength, which complements the repair action of keratins.
- Biotinyl-GHK (Biotinoyl Tripeptide-1) (ID 6891): This peptide links Biotin with GHK, which binds to hair proteins to accelerate hair growth and strengthen the hair root.
- Usage Rate: 1-3% (recommend 3%).
