Isopropyl Myristate
Also known as: IPM, Isopropyl tetradecanoate, Myristic acid ester
The classic fast-dry emollient — light, cheap, and effective, with a famous comedogenicity footnote worth understanding.
In short
Isopropyl myristate (IPM) is an ester of isopropyl alcohol and myristic acid (from coconut/palm), used in cosmetics since the 1950s as a light emollient and solvent. It spreads easily, dries to a non-greasy finish, and helps other ingredients penetrate — properties that made it a staple of lotions, makeup removers, and topical drugs. Its one famous footnote: 1970s rabbit-ear testing rated it highly comedogenic, a label that stuck despite later human data showing far less pore-clogging at cosmetic concentrations. It is well tolerated by most people, with rare irritation; acne-prone individuals may prefer alternatives, but the scare exceeds the science.
- Ester of isopropyl alcohol + myristic acid (coconut-derived)
- Light, fast-drying emollient and penetration aid
- 1950s–present cosmetic staple; also in topical drugs
- Comedogenic reputation from rabbit tests; human data milder
What is Isopropyl Myristate?
Isopropyl myristate has been softening skin since the 1950s, and its formula reads like an emollient's résumé: light, fast-drying, spreadable, cheap, and an excellent carrier for actives. Its reputation, however, carries one famous scar — early rabbit-ear studies branded it a pore-clogger, and decades of ingredient lists have repeated the label. The modern read is more forgiving: human data show modest comedogenicity at real concentrations, and for most skin, IPM is simply a workhorse. It is a case study in how one old animal assay shaped decades of ingredient anxiety.
Where it comes from
Natural sources
- Synthesized from myristic acid (coconut/palm source) and isopropyl alcohol
- A light ester oil — lower viscosity than most vegetable oils
How it's made
Colorless liquid; used at 1–20% in lotions, makeup, and topical pharmaceuticals.
What it does in products
Benefits
Non-greasy skin softening
strong evidenceDelivers emollience without the residue of heavier oils — the reason it anchors body lotions and makeup removers.
Actives penetration
strong evidenceEnhances skin absorption of co-formulated actives and drugs — a documented, functional role in topical pharmaceuticals.
Good tolerability in practice
moderate evidenceLow irritation rates in human testing; the severe comedogenicity label from rabbit assays overstates real-world risk at cosmetic concentrations.
Side effects & safety
Safety considerations
- Considered safe topically.
- None.
- Not for: None; acne-prone skin may prefer alternatives
How it's used
In supplements
Not an oral ingredient.
In skincare
1–20% in lotions, removers, and leave-on products.
Regulatory status
- Permitted cosmetic ingredient; also an inactive ingredient in approved topical drugs.
- INCI name on cosmetic labels: Isopropyl Myristate.
- CIR-reviewed and found safe in cosmetics.
Popular products containing Isopropyl Myristate
- Classic body lotions (e.g., Jergens) — IPM-anchored lotion basesJergens · Skincare
- Neutrogena makeup removers — IPM in cleansing oilsNeutrogena · Skincare
- Topical drug formulations (as excipient) — Standard penetration-aiding excipientVarious · OTC drug
Product names and brands are shown for reference and belong to their respective owners.
The rabbit-ear legacy
The 1970s rabbit-ear comedogenicity assay rated IPM among the worst pore-cloggers, and the number 5/5 has haunted it ever since. Rabbit ears are exquisitely sensitive to pore-clogging — far more than human facial skin — and later human testing found modest comedogenicity at best. The lesson generalizes: single-number comedogenicity ratings deserve skepticism.
The penetration trade-off
IPM's penetration-enhancing property is exactly why it is in topical drugs — and why some formulators avoid it in acne products: the same mechanism can help actives in and, theoretically, push other ingredients deeper. For most cosmetic uses, the trade is invisible and benign.
Frequently asked questions
Will isopropyl myristate break me out?
For most people, no — human data show modest comedogenicity, well below the rabbit-test reputation. Acne-prone skin may patch-test or choose alternatives.
Is IPM safe?
Yes — decades of use with low irritation, and CIR-reviewed as safe at cosmetic concentrations.
Why is IPM in topical medications?
It enhances drug penetration through the skin — a standard excipient function in creams and gels.
The bottom line
Isopropyl myristate is a competent, well-tolerated emollient whose pore-clogging reputation is a relic of rabbit ears — useful, ubiquitous, and milder than its legend.
References
- Isopropyl myristate — Cosmetic Ingredient Review. CIR. https://www.cir-safety.org/ingredients
- Comedogenicity: from rabbit ears to human data. PubMed Central. https://pubmed.ncbi.nlm.nih.gov/31605990/
- Penetration enhancers in topical formulations. PubMed. https://pubmed.ncbi.nlm.nih.gov/28257056/