What Is Acetyl Norleucyl Dipeptide-54 D-Phenylalanyl Dipeptide-25 Amide?
Acetyl Norleucyl Dipeptide-54 D-Phenylalanyl Dipeptide-25 Amide is a lab crafted peptide complex created by linking norleucine, two small dipeptide fragments, and the amino acid D-phenylalanine, then capping the chain with an acetyl group at one end and an amide group at the other. These small structural tweaks help the molecule stay stable on the skin and improve its ability to interact with the surface layers. Peptide technology first gained traction in the early 2000s as brands searched for gentler ways to signal skin repair and firmness. Since then formulators have been exploring ever more targeted peptide sequences, leading to the development of multi-unit blends like this one that focus on reinforcing the skin barrier.
The ingredient is produced through solid-phase peptide synthesis, a step-by-step process that builds the chain one amino acid at a time on a resin support. Once the sequence is complete it is acetylated and converted to its amide form, then purified and dried into a fine powder ready for cosmetic use.
You will most often spot Acetyl Norleucyl Dipeptide-54 D-Phenylalanyl Dipeptide-25 Amide in leave-on products where a protective film is desirable. Common formats include lightweight serums, barrier repair moisturizers, soothing creams for sensitive skin, eye treatments, post-procedure masks and anti-aging blends that promise to shield against daily stressors.
Acetyl Norleucyl Dipeptide-54 D-Phenylalanyl Dipeptide-25 Amide’s Cosmetic Benefits/Uses
This peptide brings a focused benefit to skin care formulations.
Skin protecting: By forming a breathable film on the surface it helps defend against pollution, harsh weather and other external aggressors. At the same time it supports the skin’s natural barrier function, which can lessen irritation, reduce moisture loss and promote a smoother, healthier looking complexion.
Who Can Use Acetyl Norleucyl Dipeptide-54 D-Phenylalanyl Dipeptide-25 Amide
This peptide is considered friendly for most skin types. Dry and sensitive complexions appreciate the extra barrier support while balanced or mature skin can benefit from the protective film it leaves behind. Very oily or acne-prone skin may find the finish a touch too occlusive if the rest of the formula is already rich but the ingredient itself is not known to trigger breakouts.
The material is made entirely through laboratory synthesis so it contains no animal derived components, making it suitable for both vegans and vegetarians.
Current research shows no specific issues for pregnant or breastfeeding users when the ingredient is applied topically in cosmetic amounts. Still this is not medical advice, so anyone who is pregnant or nursing should have their healthcare provider review all skincare products they plan to use just to be safe.
Acetyl Norleucyl Dipeptide-54 D-Phenylalanyl Dipeptide-25 Amide is not photosensitising and does not increase the skin’s sensitivity to sunlight. Normal daytime sun protection habits are sufficient.
Potential Side Effects/Adverse Reactions
Reactions to topical Acetyl Norleucyl Dipeptide-54 D-Phenylalanyl Dipeptide-25 Amide differ from person to person. The points below outline potential issues yet most users will not encounter them when the ingredient is properly formulated and used as directed.
- Mild redness or warmth
- Transient stinging on very compromised skin
- Rare allergic contact dermatitis in individuals sensitive to specific peptide sequences
- Product pilling if layered over heavy silicones or under thick makeup
If any unwanted reaction occurs stop using the product and seek advice from a qualified healthcare professional.
Comedogenic Rating
Rating: 1 (very low likelihood of clogging pores). Acetyl Norleucyl Dipeptide-54 D-Phenylalanyl Dipeptide-25 Amide is a large, water friendly peptide that sits on the skin surface rather than soaking into pores, so it does not behave like heavy oils or waxes that can trap debris. Its film forming action is light and breathable which keeps the risk of congestion low. This makes the ingredient generally suitable for people prone to acne or breakouts. If a finished product using this peptide feels rich or greasy, that effect usually comes from other ingredients in the formula rather than the peptide itself.
Summary
Acetyl Norleucyl Dipeptide-54 D-Phenylalanyl Dipeptide-25 Amide is a lab designed peptide that mainly protects skin by forming a thin flexible shield which helps reduce moisture loss and defend against daily stress. It also supports the natural barrier so redness and dryness are less likely. While not yet a household name it is popping up in more barrier repair serums and moisturizers as brands expand their peptide lineups. Safety data shows it is well tolerated for most users, with only rare mild reactions. As with any new skincare ingredient it is smart to patch test first to check personal compatibility before applying it all over the face.