Humectant

Hydroxypropyl Bis-Hydroxyethyldimonium Chloride

INCI: HYDROXYPROPYL BIS-HYDROXYETHYLDIMONIUM CHLORIDE

Reviewed by Daisy · Last updated 14 Aug 2026

A conditioning agent that helps skin retain moisture and maintain its natural barrier

Best For Skin Types

All, Dry, Sensitive, Mature

Addresses

Dryness, Hydration, Barrier repair

Usage Frequency

Daily

What Is Hydroxypropyl Bis-Hydroxyethyldimonium Chloride?

Hydroxypropyl bis-hydroxyethyldimonium chloride is a quaternary ammonium compound derived from chitosan, a natural polysaccharide sourced from crustacean shells. It functions as both a humectant and skin conditioning agent, meaning it draws water into the skin whilst also helping to smooth and soften the skin surface.

This ingredient is particularly valued in formulations designed to support hydration and barrier health, as it can help reduce transepidermal water loss and improve the overall feel and appearance of the skin.

How It Works

This ingredient works through two primary mechanisms. As a humectant, it has a hygroscopic structure that attracts water molecules from both the environment and deeper skin layers, drawing them towards the outer layers of the skin. This helps counteract dryness and maintain a more plump, hydrated appearance.

Additionally, its quaternary ammonium structure allows it to adhere to the skin surface and hair, forming a light conditioning film. This film helps reduce water loss from the skin and creates a smoother feel by temporarily filling in micro-irregularities on the skin's surface.

Clinical Evidence & References

Research into chitosan-derived quaternary ammonium compounds suggests they have potential benefits for wound healing and skin barrier support, though most published studies focus on medical applications such as wound dressings rather than cosmetic skincare. The evidence base for this specific ingredient in cosmetic formulations is more limited.

The humectant and conditioning properties are well-established in formulatory science, and the ingredient's safety profile in cosmetic use is generally considered favourable. However, more targeted clinical studies specifically examining its efficacy in skincare products would help clarify its benefits at typical cosmetic concentrations.

How to Use

This ingredient is best used as part of a complete skincare routine rather than as a standalone treatment. It works well in moisturisers, serums, and hydrating toners, where it can work synergistically with other humectants and emollients. For optimal results, apply to damp skin to help lock in additional hydration, and use consistently as part of your daily routine.

Safety & Precautions

Generally well-tolerated in cosmetic formulations. Those with known sensitivity to quaternary ammonium compounds or chitosan should patch-test 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