Acetyl
Tetrapeptide-5.

What is Acetyl Tetrapeptide-5?

Acetyl Tetrapeptide-5 is a synthetic peptide made up of four amino acids with an acetyl group attached for stability. It was developed by Lipotec (now part of Lubrizol) and is marketed as Eyeseryl, specifically for eye-area cosmetics.

Eye-area skin is biologically different from the rest of the face: it's about half as thick, has fewer oil glands, and sits over a dense network of small blood vessels. That's why fluid retention, vascular pooling, and even a poor night's sleep show up so visibly under the eyes, and why the eye area benefits from peptides designed for it.

How does it work?

Eyeseryl was developed to address two of the main visible drivers of puffy, tired-looking eyes:

• Fluid retention. Under-eye puffiness, especially in the morning, is largely caused by lymphatic and interstitial fluid pooling in the thin tissue. Acetyl Tetrapeptide-5 has been studied for supporting the look of reduced fluid build-up.
• Visible micro-bruising / vascular pooling. The "bluish" component of dark circles often comes from blood pooling beneath thin under-eye skin. Lipotec's research suggests Eyeseryl supports the look of more even-toned, less shadowed under-eyes through effects on permeability of small vessels.

It's worth being clear about what it does not do. It doesn't fill volume loss or tear troughs (a structural concern). It doesn't significantly brighten surface pigmentation under the eyes (that's a job for brightening peptides like Oligopeptide-68). It doesn't replace sleep.

What does the research show?

Lipotec's published research includes a 30-day in-vivo study of women aged 30-55 with under-eye puffiness, showing improvements in puffiness and dark-circle appearance compared to placebo. Eyeseryl has since been a routine entrant in independent peer-reviewed reviews of "evidence-based" eye-cream peptides.

As with other cosmetic peptides, the gains are visible but not dramatic. Most users report a "more rested-looking" effect after 4-8 weeks, often layered with the immediate visible decongestion caffeine provides.

Who is Acetyl Tetrapeptide-5 for?

• Anyone with morning under-eye puffiness from fluid retention, allergies, or sleep patterns.
• Bluish-toned dark circles driven by vascular pooling rather than surface pigment.
• People who travel often, long flights, dehydration, and altitude all worsen under-eye fluid retention.
• People who use retinol around the eyes, the peptide layers comfortably with retinol and can be the "morning partner" to evening retinol.

How to use it

Apply morning and evening to the orbital bone and inner under-eye corner. The morning application is the more impactful one, puffiness from overnight fluid retention is at its peak when you wake up, and the cooling effect from accompanying caffeine and EGCG is an immediate visual reset.

In a stick format like the Depuff stick, the cool, solid balm-serum format is a natural fit for the eye area: the cooling glide itself contributes to the de-puff experience, the targeted application avoids product migration into the eye, and the hygiene profile of a stick (no fingertips, no dropper) is safer for the delicate eye area than most other formats.

Common questions

Does Acetyl Tetrapeptide-5 work without caffeine?

The peptide's signaling effects work on their own, but in practice it's almost always formulated with caffeine and EGCG because the combination gives both immediate visible decongestion and the slower signaling change. The Depuff stick uses this standard combination.

Can it be used on the eyelids?

Yes, but apply carefully, eyelid skin is the thinnest on the face. Most use is on the orbital bone, under-eye, and outer corner; the formula migrates inward over time.

Will it help under-eye hollows?

No. Hollow shadow is a structural concern, fat pad position, bone structure, volume loss, which is not addressable with any topical. Acetyl Tetrapeptide-5 is for fluid- and vascular-driven under-eye look.