Humectant

PEG-6

Reviewed by Daisy · Last updated 14 Aug 2026

A lightweight humectant and solvent that helps formulations absorb and deliver other actives

Best For Skin Types

All, Dry, Combination

Addresses

Dryness, Hydration, Barrier repair

Usage Frequency

Daily

What Is PEG-6?

PEG-6 is a polyethylene glycol—a synthetic polymer derived from ethylene oxide. It functions as both a humectant (drawing moisture into the skin) and a solvent (helping dissolve and stabilise other ingredients in a formula). It appears in roughly 0.2% of skincare products, typically in small concentrations as a supporting ingredient rather than a primary active.

As a humectant, PEG-6 works by attracting water molecules to the skin's surface. As a solvent, it enables better mixing of water-loving and oil-loving ingredients, which helps formulations remain stable and allows active ingredients to penetrate more effectively.

How It Works

PEG-6 is hygroscopic, meaning it has an affinity for water and will absorb moisture from both the environment and deeper skin layers, drawing it towards the surface. This hydrating action supports the skin's natural moisture balance, particularly useful in drier or dehydrated states.

As a solvent, PEG-6 dissolves readily in both water and oils, making it a useful bridge between incompatible ingredients. This property allows formulators to create stable, homogeneous products and can enhance the skin penetration of active ingredients that might otherwise struggle to reach viable skin layers.

Clinical Evidence & References

Research into PEGs and their derivatives suggests they can influence how other skincare actives (such as niacinamide) are delivered into the skin, though results vary depending on what other solvents are used alongside PEG-6. The ingredient has a long history of use in cosmetics and pharmaceuticals with an established safety profile.

Evidence specific to PEG-6 as a standalone humectant is limited in the published literature. Most efficacy data relates to PEGs in combination with other ingredients or in specific delivery systems, so broader claims about its hydrating capacity should be treated with appropriate caution.

How to Use

PEG-6 is not typically the main active in a product; it works best as part of a formulation with complementary humectants (such as glycerin) and actives. Apply products containing PEG-6 to clean, damp skin to maximise its water-attracting properties. Use consistently as directed, usually twice daily as part of your routine.

Safety & Precautions

PEG-6 is generally well-tolerated and considered safe for topical use in cosmetics. It is poorly absorbed systemically and does not penetrate deeply into viable skin layers, minimising risk of systemic effects.

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

Part of a family

PEG-6 is a variant of PEG-75, the form you will most often see on an ingredients list.

Functions as a humectant to boost skin’s hydration | May also be used as a solvent to mesh ingredients cohesively and enhance formulary texture

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