Acetyl Tetrapeptide-5 is a synthetic four-amino-acid peptide derivative used primarily in cosmetic and skincare formulations, especially products targeting under-eye puffiness, dark circles, and signs of fatigue.
Basic information
- INCI name: Acetyl Tetrapeptide-5
- Type: Acetylated tetrapeptide
- Category: Cosmetic peptide / skin-conditioning active
- Primary application: Eye-area and anti-aging skincare
- Main positioning: Helps improve the appearance of puffiness, under-eye bags, and tired-looking skin
- Commonly associated commercial ingredient: Eyeseryl®, although commercial preparations may contain additional ingredients and should not be assumed to be identical to pure Acetyl Tetrapeptide-5.
How it is thought to work
Acetyl Tetrapeptide-5 is generally described as a peptide designed to address several factors contributing to the appearance of under-eye puffiness. Proposed cosmetic mechanisms include:
- Reducing the appearance of fluid-related puffiness around the eye area.
- Supporting skin elasticity and smoothness, making the eye contour appear more even.
- Improving the visual appearance of dark circles, particularly when they are associated with puffiness and skin quality.
- Helping reduce the appearance of fine lines by improving the overall condition and hydration of the skin.
It is important to distinguish these cosmetic effects from treatment of medical causes of eye bags or dark circles. Evidence for specific molecular mechanisms is considerably less extensive than the marketing descriptions sometimes suggest.
Main cosmetic benefits
| Benefit | Typical cosmetic purpose |
| Anti-puffiness | Helps make the eye area look less swollen |
| Under-eye care | Improves the appearance of tired-looking eyes |
| Fine-line care | Helps smooth the appearance of small wrinkles |
| Skin conditioning | Supports a smoother, softer skin appearance |
| Dark-circle appearance | May help improve the appearance of some types of dark circles |
Where it is used
Acetyl Tetrapeptide-5 is particularly suitable for:
- Eye creams
- Eye serums
- Anti-aging serums
- Depuffing treatments
- Dark-circle products
- Facial creams targeting fine lines
It is usually formulated at relatively low concentrations because peptides are potent cosmetic actives and can be relatively expensive compared with conventional moisturizers.
Important limitation
“Dark circles” and “eye bags” have multiple causes, including pigmentation, visible blood vessels, shadows from anatomical structure, fat pads, aging, and fluid retention. Acetyl Tetrapeptide-5 is therefore best regarded as a cosmetic ingredient for improving appearance rather than a universal treatment for all forms of dark circles or eye bags.
If you’re studying it from a formulation/scientific perspective, the next useful topics are its chemical structure and physical properties, mechanism of action, efficacy, recommended concentration, formulation stability, and Acetyl Tetrapeptide-5 vs. other eye-area peptides.