Ingredient review
Castoryl Maleate
INCI: Castoryl Maleate
A gentle, castor-oil-derived ingredient that helps products feel smooth and stay put without clogging pores.
In plain English
Castoryl Maleate is a modified version of castor oil, created by combining castor oil with maleic acid. In skincare and makeup, it acts as a lightweight emollient that softens the skin and forms a thin, flexible film to help products last longer and resist water. It's especially common in lip products and long-wear foundations because it improves slip and adhesion without feeling greasy or heavy.
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
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Castoryl Maleate 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 Castoryl Maleate.
- 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 semi-synthetic ester made by reacting castor oil with maleic anhydride, resulting in a film-forming emollient that is stable and non-greasy.
How it works
It spreads easily over the skin, reducing friction and providing a smooth feel. Its film-forming property creates a subtle barrier that helps other ingredients stay in place and improves water resistance, while still allowing the skin to breathe.
Pros
Enhances wear time
Forms a flexible film that helps makeup and lip products stay put longer, even through eating or drinking.
Lightweight feel
Unlike some oils, it doesn't leave a heavy or sticky residue, making it comfortable for everyday wear.
Cons and cautions
Not deeply moisturizing
While it softens the skin, it doesn't provide the deep hydration that heavier oils or butters can offer.
Semi-synthetic origin
Some consumers prefer fully natural ingredients; this is a chemically modified version of castor oil.
Best for
- Anyone looking for long-wear lip or face makeup
- Those with normal to combination skin who prefer non-greasy textures
Use caution if
- Individuals with known castor oil allergy (rare)
- Those seeking purely natural or unprocessed ingredients
Usage tips
Safety summary
Castoryl Maleate has a low irritation and comedogenic risk. It is well-tolerated in most formulations and considered safe at typical use levels. No significant safety concerns have been reported in cosmetic use.
Research notes
While not extensively studied on its own, Castoryl Maleate is a derivative of castor oil, which has a long history of safe use. Its film-forming and emollient properties are well-documented in cosmetic chemistry literature.
Common label clues
- Typical concentration
- 1% to 10% depending on the formula
- Regulatory status
- Approved for use in cosmetics in the US, EU, and other major markets. Listed in the CosIng database as a safe ingredient.
- Common uses
- Lipsticks, Lip balms, Foundations, Water-resistant sunscreens, Eye makeup
- Environmental note
- Derived from castor oil, a renewable plant source, but the chemical modification process may involve solvents and energy use.
Good to know
- Castoryl Maleate is often used in combination with other film-formers like VP/Hexadecene Copolymer for extra durability.
- It is considered safe by major cosmetic safety panels.
Common questions
What is Castoryl Maleate in beauty products?
Castoryl Maleate is a modified version of castor oil, created by combining castor oil with maleic acid. In skincare and makeup, it acts as a lightweight emollient that softens the skin and forms a thin, flexible film to help products last longer and resist water. It's especially common in lip products and long-wear foundations because it improves slip and adhesion without feeling greasy or heavy.
What does Castoryl Maleate do in a beauty product?
It spreads easily over the skin, reducing friction and providing a smooth feel. Its film-forming property creates a subtle barrier that helps other ingredients stay in place and improves water resistance, while still allowing the skin to breathe.
Is Castoryl Maleate safe for most people?
Castoryl Maleate has a low irritation and comedogenic risk. It is well-tolerated in most formulations and considered safe at typical use levels. No significant safety concerns have been reported in cosmetic use.
Who should be careful with Castoryl Maleate?
Individuals with known castor oil allergy (rare) Those seeking purely natural or unprocessed ingredients
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.