Ingredient review
Isostearyl Myristate
INCI: Isostearyl Myristate
A reliable emollient that makes skin feel soft, but may clog pores for those prone to breakouts.
In plain English
Isostearyl Myristate is an oil-like ingredient made from a fatty alcohol (isostearyl alcohol) and myristic acid, a fatty acid found in nutmeg and other plants. It's added to creams, lotions, and makeup to make them feel silky and spread easily, leaving skin smooth and hydrated. Think of it as a skin-friendly oil that helps other ingredients glide on without greasiness.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is low; clogging risk is moderate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- moderate
Quick decision guide
Useful, but context matters
Isostearyl Myristate can be useful, but watch for possible clogging concerns.
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 Isostearyl Myristate.
- 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
moderateMay be fine for many users but deserves caution if you are breakout-prone.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A synthetic ester created by combining isostearyl alcohol (a branched-chain fatty alcohol) with myristic acid (a saturated fatty acid). It's a clear, odorless liquid that mimics the feel of natural skin oils.
How it works
Sits on the skin's surface to fill in tiny gaps between skin cells, temporarily smoothing roughness and reducing water loss. It also helps other ingredients spread evenly and gives products a luxurious, non-greasy feel.
Pros
Silky texture
Creates a smooth, velvety feel on skin without heavy greasiness, making it ideal for luxurious creams and lip products.
Moisture retention
Helps reduce transepidermal water loss (water that evaporates from your skin), keeping skin hydrated longer.
Cons and cautions
May clog pores
Rated moderately comedogenic, meaning it can block pores and cause blackheads or breakouts in acne-prone individuals.
Synthetic origin
Manufactured in a lab, which may be a turn-off for those seeking 100% natural or plant-derived ingredients.
Best for
- People with dry or normal skin looking for lightweight moisture
- Anyone who enjoys silky, spreadable creams and makeup
Use caution if
- Those with oily or acne-prone skin should patch test first due to moderate comedogenic potential
Usage tips
Safety summary
Isostearyl Myristate is considered safe for most skin types at typical cosmetic concentrations. The main concern is its moderate comedogenic potential, which may cause breakouts in acne-prone individuals. No significant toxicity or irritation has been reported in standard safety assessments.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel have concluded that isostearyl myristate is safe as used in cosmetics. Studies focus on its emollient properties and skin compatibility, with no evidence of systemic toxicity or sensitization at typical use levels.
Common label clues
- Typical concentration
- 1% to 10%
- Regulatory status
- Approved for use in cosmetics in the US (FDA), EU (CosIng), and many other regions. No concentration restrictions are commonly imposed.
- Common uses
- Moisturizers, Lipsticks, Foundations, Body lotions, Sunscreens
- Environmental note
- Synthetic esters like this are generally biodegradable, but their production relies on petrochemical or plant-derived fatty acids, which have varying environmental footprints.
Good to know
- Isostearyl Myristate is often used in lipsticks to provide a smooth, non-drying application.
- It's considered safe for use in cosmetics by major regulatory bodies when used within typical concentrations.
Common questions
What is Isostearyl Myristate in beauty products?
Isostearyl Myristate is an oil-like ingredient made from a fatty alcohol (isostearyl alcohol) and myristic acid, a fatty acid found in nutmeg and other plants. It's added to creams, lotions, and makeup to make them feel silky and spread easily, leaving skin smooth and hydrated. Think of it as a skin-friendly oil that helps other ingredients glide on without greasiness.
What does Isostearyl Myristate do in a beauty product?
Sits on the skin's surface to fill in tiny gaps between skin cells, temporarily smoothing roughness and reducing water loss. It also helps other ingredients spread evenly and gives products a luxurious, non-greasy feel.
Is Isostearyl Myristate safe for most people?
Isostearyl Myristate is considered safe for most skin types at typical cosmetic concentrations. The main concern is its moderate comedogenic potential, which may cause breakouts in acne-prone individuals. No significant toxicity or irritation has been reported in standard safety assessments.
Who should be careful with Isostearyl Myristate?
Those with oily or acne-prone skin should patch test first due to moderate comedogenic potential
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.