Ingredient review
Diethylene Glycol Diisononanoate
INCI: DIETHYLENE GLYCOL DIISONONANOATE
A lightweight synthetic emollient that gives a silky, non-greasy feel to products, with a low risk of irritation or clogging pores.
In plain English
Diethylene Glycol Diisononanoate is a man-made oil-like ingredient used in cosmetics to make products feel smooth and silky without being greasy. It helps spread other ingredients evenly on the skin and leaves a soft, velvety finish. Think of it as a lightweight, non-sticky moisturizer helper that also helps sunscreen and makeup glide on easily.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Diethylene Glycol Diisononanoate is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Diethylene Glycol Diisononanoate.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A synthetic ester made from diethylene glycol and isononanoic acid. It is a clear, nearly odorless liquid that acts as an emollient and skin conditioning agent in cosmetic formulations.
How it works
It sits on the surface of the skin, filling in tiny gaps between skin cells to create a smooth, even texture. It also reduces friction, helping products spread more easily, and leaves a non-greasy, velvety after-feel.
Pros
Lightweight feel
Unlike heavier oils, this ingredient leaves a silky, non-sticky finish that works well for oily and combination skin types.
Improves product texture
It helps creams and lotions spread smoothly and evenly, making application more pleasant and reducing the amount of product needed.
Cons and cautions
Synthetic origin
Made from petrochemical-derived materials, which may be a concern for those seeking natural or plant-based alternatives.
Limited skin benefit data
While safe as a cosmetic ingredient, there is less research on its long-term effects on skin health compared to some naturally derived emollients.
Best for
- People with normal to oily skin who prefer lightweight textures
- Anyone looking for a non-greasy emollient in moisturizers or sunscreens
Use caution if
- Those who strictly avoid synthetic ingredients in their skincare
Usage tips
Safety summary
Diethylene Glycol Diisononanoate is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, making it suitable for most skin types. However, as with any synthetic ingredient, those with very sensitive skin should patch-test first.
Research notes
Research on this specific ester is limited, but it is structurally similar to other diethylene glycol esters that have been evaluated by the Cosmetic Ingredient Review panel and found safe. Most safety data comes from industry assessments rather than independent clinical trials.
Common label clues
- Typical concentration
- 1% to 10%
- Regulatory status
- Approved for use in cosmetics by the FDA and the European Commission. The Cosmetic Ingredient Review (CIR) panel has reviewed similar diethylene glycol esters and found them safe for use in rinse-off and leave-on products at typical concentrations.
- Common uses
- Moisturizers, Sunscreens, Foundations, Lip products, Hair conditioners
- Environmental note
- As a synthetic compound, it may not be biodegradable in all conditions. However, it is used in low concentrations and is not known to bioaccumulate.
Good to know
- It is often used in sunscreens to improve the feel of mineral filters like zinc oxide.
- The ingredient is not water-soluble, so it is typically found in oil-phase formulations.
Common questions
What is Diethylene Glycol Diisononanoate in beauty products?
Diethylene Glycol Diisononanoate is a man-made oil-like ingredient used in cosmetics to make products feel smooth and silky without being greasy. It helps spread other ingredients evenly on the skin and leaves a soft, velvety finish. Think of it as a lightweight, non-sticky moisturizer helper that also helps sunscreen and makeup glide on easily.
What does Diethylene Glycol Diisononanoate do in a beauty product?
It sits on the surface of the skin, filling in tiny gaps between skin cells to create a smooth, even texture. It also reduces friction, helping products spread more easily, and leaves a non-greasy, velvety after-feel.
Is Diethylene Glycol Diisononanoate safe for most people?
Diethylene Glycol Diisononanoate is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, making it suitable for most skin types. However, as with any synthetic ingredient, those with very sensitive skin should patch-test first.
Who should be careful with Diethylene Glycol Diisononanoate?
Those who strictly avoid synthetic ingredients in their skincare
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.