What Is Dipeptide-9?
Dipeptide-9 is a lab-made short chain peptide created by bonding two naturally occurring amino acids, glutamic acid and lysine. Because it is synthetic, chemists can control its purity and stability, qualities that help it perform reliably in cosmetic formulas. Peptides started gaining momentum in beauty products in the early 2000s when researchers found they could target skin and hair concerns without the heaviness of traditional oils. Dipeptide-9 soon emerged as a versatile option thanks to its dual affinity for water and protein-rich surfaces.
Manufacturing begins with solid phase peptide synthesis, a step-by-step process that attaches protected glutamic acid to a resin, then couples lysine to form the two-amino-acid chain. After the sequence is complete, the peptide is cleaved from the resin, purified through filtration and freeze-dried into a fine powder. Formulators then dissolve this powder in water or a light solvent, add stabilizers if needed, and blend it into finished products.
You will most often see Dipeptide-9 in lightweight leave-in conditioners, hair masks, hydrating serums, daily moisturizers, anti aging creams and specialty treatments aimed at boosting moisture and softness.
Dipeptide-9’s Cosmetic Benefits/Uses
Below are the main ways Dipeptide-9 supports skin and hair care formulas
- Hair conditioning: The peptide binds lightly to the hair shaft, smoothing rough cuticles and making strands feel softer, look shinier and detangle more easily without weighing them down
- Humectant: Its structure attracts water molecules, drawing moisture from the environment into the product and onto the surface of skin or hair, which helps maintain hydration throughout the day
- Skin conditioning: By laying down a thin, flexible film, Dipeptide-9 leaves skin feeling silky and supple while helping to reduce the appearance of minor roughness or fine lines
Who Can Use Dipeptide-9
Dipeptide-9 is generally well tolerated by all skin types including dry, oily, combination and sensitive skin because it is lightweight, water loving and non greasy. People with very reactive or allergy-prone skin may still prefer a shorter ingredient list so checking the full product label is wise, but the peptide itself is considered low risk.
The ingredient is synthetic and produced entirely in a lab without any animal-derived inputs or by-products so it is suitable for both vegans and vegetarians.
Current data shows no known hormonal activity or reproductive concerns, so pregnant or breastfeeding women can typically use products containing Dipeptide-9. This is not medical advice and anyone who is expecting or nursing should run new products past a qualified health professional just to be safe.
Dipeptide-9 is not known to cause photosensitivity, meaning it will not make skin more prone to sunburn. Standard daytime sun protection habits should still be followed.
Potential Side Effects/Adverse Reactions
Side effects from the topical use of Dipeptide-9 can vary from person to person. The points below list potential but uncommon reactions. When formulated and used correctly most people will experience none of these issues.
- Mild redness or itching
- Temporary stinging on very compromised skin
- Rare allergic contact dermatitis
- Eye irritation if the product accidentally enters the eyes
If any discomfort or visible irritation develops stop using the product and consult a healthcare professional if symptoms persist.
Comedogenic Rating
Rating: 0/5. Dipeptide-9 is water soluble, lightweight and free of heavy oils or waxes that can block pores, so it does not create the kind of occlusive layer that encourages comedones. This makes it suitable for people who are prone to acne or breakouts. As always, the overall comedogenicity of a finished product also depends on the other ingredients and the formula’s texture.
Summary
Dipeptide-9 serves mainly as a humectant, hair conditioner and skin conditioner. Its peptide structure attracts and holds water, helping hair and skin stay hydrated, while its mild affinity for protein surfaces lets it smooth cuticles and leave a soft, flexible film that feels silky rather than greasy.
The ingredient is still a niche player compared with long-standing moisturizers like hyaluronic acid, but it is gaining traction in modern lightweight formulas that aim for high performance with a minimal feel.
Current research shows Dipeptide-9 to be low risk, non sensitizing and vegan friendly. Most users tolerate it well, yet skin is personal so it is wise to patch test any new product that features this peptide before full use, especially if you have a history of sensitivities.