Ingredient guide · A

Acetyl Tetrapeptide-9

Acetyl Tetrapeptide-9 is a synthetic peptide used in anti-ageing skincare to help improve skin firmness and smoothness. It is commonly found in serums, creams and eye treatments aimed at mature skin. Shoppers like it for its targeted action on the skin’s support structure without irritation.

Acetyl Tetrapeptide-9 — Acetyl Tetrapeptide-9 is a lab-made peptide created by combining four amino acids (lysi… | UK Lips ingredient guide

How it works in skincare

In cosmetics Acetyl Tetrapeptide-9 works by stimulating the synthesis of key dermal components such as collagen and lumican. By encouraging these structural proteins it helps reinforce the extracellular matrix, improving skin density and reducing the appearance of fine lines. It is valued in UK formulations for its ability to deliver visible firming and smoothing results in leave-on products while remaining gentle enough for daily use.

Key benefits

  • Helps improve skin firmness
  • Enhances skin smoothness
  • Supports dermal density
  • Reduces the appearance of fine lines
  • Promotes a more youthful-looking complexion
  • Suitable for daily anti-ageing routines

Best for

mature skin, ageing skin, loss of firmness, fine lines and wrinkles

Where it comes from

Acetyl Tetrapeptide-9 is a lab-made peptide created by combining four amino acids (lysine, threonine, serine and proline) followed by acetylation. It does not come directly from a plant, seed or mineral but is inspired by natural peptide sequences found in human skin.

Products with Acetyl Tetrapeptide-9

Not every product on UK Lips lists a full ingredient breakdown — so there may be many more formulas that contain Acetyl Tetrapeptide-9 than we can show here. These are the comparisons where we’ve confirmed it in the listed ingredients.

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