Humectant

Serum Protein

INCI: SERUM PROTEIN

Reviewed by Kate · Last updated 2 Jun 2026

A protein-derived conditioning agent that helps support skin hydration and texture

Best For Skin Types

All, Dry, Combination, Mature

Addresses

Dryness, Hydration, Barrier repair

Usage Frequency

Daily

What Is Serum Protein?

Serum protein is a naturally derived ingredient sourced from blood serum. In skincare formulations, it functions primarily as a humectant and skin conditioning agent, meaning it helps attract and retain moisture whilst supporting the skin's overall feel and appearance.

The protein molecules work to film-form on the skin surface, creating a protective layer that can help reduce transepidermal water loss. This makes it particularly useful in products designed to improve hydration and skin softness.

How It Works

Serum protein works through two main mechanisms. As a humectant, it attracts water molecules from the environment and deeper skin layers, drawing them towards the outer layers of the skin. This increases skin hydration and plumpness.

Additionally, the protein molecules deposit a thin, conditioning film on the skin surface. This film acts as a semi-occlusive barrier, reducing the amount of moisture that evaporates from the skin whilst also smoothing the skin's texture and improving its tactile feel.

Clinical Evidence & References

Research on serum protein in skincare is limited, and most supporting evidence comes from ingredient supplier data and established cosmetic chemistry principles rather than robust clinical trials. The ingredient's conditioning and hydrating functions are well-established in the cosmetic industry, but independent peer-reviewed studies specifically evaluating its efficacy in skincare products are sparse.

The ingredient appears to be well-tolerated in topical formulations, though individual responses may vary depending on product formulation, concentration, and skin sensitivity.

How to Use

Serum protein is typically found in moisturisers, serums, and hydrating masks. Apply to clean skin as part of your regular routine. If combining with other actives, introduce it gradually to monitor tolerance. It pairs well with other humectants and can be layered under occlusive moisturisers for enhanced hydration benefit.

Safety & Precautions

Serum protein is generally considered well-tolerated in topical skincare. Those with known sensitivities to animal-derived ingredients should check product sourcing before use.

Frequently Asked Questions

From the Clinic

Not sure what your skin actually needs?

Two minutes, a few questions, and we’ll point you at what matters — no guesswork.

Take the skin quiz

Learn More About Skincare Ingredients

Explore our comprehensive ingredient glossary to understand what's in your products.

Browse All Ingredients

Authorised Stockist

Official UK retailer

Tracked Delivery

Free UK shipping over £50

5 Star Rating

Trusted by thousands

Expert Advice

Free consultations