Are plant peptides used in cosmetics and topical products?

Beyond Biopharma | Plant Protein Peptide FAQ

Short answer: Yes. Hydrolyzed plant proteins are established cosmetic ingredients and appear on labels under INCI names such as Hydrolyzed Pea Protein, Hydrolyzed Rice Protein or Hydrolyzed Soy Protein. They are usually positioned as film formers, moisture-binding and skin-conditioning ingredients rather than as actives, and any efficacy claim has to match the evidence that supports it.

How they appear on the ingredient list

In cosmetics the ingredient is named by its INCI (International Nomenclature of Cosmetic Ingredients) name rather than by a marketing term, and the INCI name normally identifies both the plant source and the fact that the protein has been hydrolyzed. That matters for two reasons. First, it tells the formulator what chemistry to expect, since a hydrolyzed protein behaves quite differently from a native isolate. Second, it gives the regulatory and safety reviewer a defined ingredient to assess. The degree of hydrolysis behind a given INCI name can still vary between suppliers, so the INCI name alone is not a full specification.

What they typically do in a formula

• Film forming - peptides adsorb onto skin and hair and leave a light, continuous film that can improve the feel of a product and help other ingredients stay in place.
• Moisture binding - the peptide chain carries polar groups that hold water, which supports a humectant or moisturizing positioning.
• Conditioning - in hair care, hydrolyzed proteins are used to improve combing, body and the perception of repair, particularly at lower molecular weights where penetration into the fiber is more plausible.
• Sensory and body - they add substance to a serum or lotion without the tackiness that some gums and high-dose humectants produce.
• Substrate for further chemistry - the peptide backbone can be used to carry other functional groups, which is common in specialty cosmetic ingredients.

Matching claims to evidence

The gap between what a peptide can do in a laboratory test and what it does on skin is where most cosmetic claim problems start. Film forming, moisture binding and conditioning are reasonable descriptions of a well-characterized hydrolyzed plant protein. Wider statements about firming, lifting or reversing wrinkles require substantially more evidence, and claim wording for cosmetics is governed by the rules of each market. The practical rule is to describe the measurable function, keep the substantiation file for whatever is claimed, and have a regulatory specialist review wording before it goes on pack.

Practical formulation points

Hydrolyzed plant proteins are usually supplied as a powder or as a preserved aqueous solution, and the form affects how they are dosed. They are compatible with most anionic and nonionic systems but can interact with cationic ingredients, so compatibility should be checked in the finished base rather than in water alone. pH and preservation matter because a protein solution is a good growth medium if preservation is inadequate, and microbial limits belong on the specification. A cosmetic brand should also keep the source statement for its own documentation and for consumer enquiries.

What to request from a supplier

Ask for the INCI name and the plant source, the grade of the material (cosmetic grade is not the same as food grade, and the two are controlled against different specifications), a certificate of analysis with the parameters that matter for your product, a molecular weight or degree of hydrolysis range, a preservative statement where relevant, and a safety or toxicological summary if one exists. Where a cosmetic use is intended, confirm that the material has been produced for that use and is documented accordingly.

Related reading

For more detail, see the use of plant hydrolysates in pet food and aquafeed, what causes color drift and off-notes and how plant peptides behave at low pH.