Acetyl Tetrapeptide-5

Acetyl Tetrapeptide-5 is a small signaling peptide commonly used in eye products at low concentrations (typically well under 1%) to help reduce puffiness; it is not pH-dependent and is not an exfoliating or keratolytic active. Available safety and cosmetic patch-test data for peptides in this class show low rates of irritation and sensitization, but reactions can still occur in highly reactive or barrier-impaired eczema patients, especially in multi-ingredient formulas. Given the generally excellent tolerability yet non-zero risk in compromised skin, it fits best as very gentle rather than inert. Safety Notes: In commercial leave-on eye gels/serums, Acetyl Tetrapeptide-5 is often supplied as a diluted trade solution and ends up in finished formulas at very low active levels (around 0.0005–0.005%) in mass-market moisturizers and multi-ingredient eye products. Higher-end or "peptide-focused" OTC eye serums and targeted de-puffing treatments commonly land around 0.01–0.02% active, with a smaller set of high-strength consumer products pushing to about 0.05% active when the marketing claim is built around the peptide. It is predominantly used in leave-on products (especially eye-area skincare); rinse-off use is uncommon and typically at similarly low levels due to limited contact time.