Isopropyl Myristate
Also known as IPM, isopropyl tetradecanoate, Crodamol IPM, Cetiol A
“CIR Expert Panel says: safe as used in cosmetics.”
ISOPROPYL MYRISTATE (CAS 110-27-0; C17H34O2) is the ester of isopropyl alcohol and myristic acid (C14 fatty acid). It is one of the most widely used synthetic emollients in cosmetics, valued for its lightweight, dry skin feel, low viscosity, and capacity to enhance percutaneous absorption of co-formulated lipophilic actives. The CIR Expert Panel originally assessed it in 1982 (JACT 1(4):55-80) alongside other isopropyl esters, reaffirmed the finding in 2002/2005 (IJT 24(S1):63-67), and included it in the 2015 amended fatty acid esters safety assessment (IJT 34(Suppl.2):5-69), concluding it is safe when formulated to be non-irritating (Finding=SQ). Comedogenicity is a documented consumer concern: Fulton et al. 1984 (PMID 6229554) classified isopropyl myristate as highly comedogenic in the rabbit ear model; it should be used with caution in formulations targeting acne-prone skin. Mechanistically, IPM disrupts the lamellar lipid structure of the stratum corneum by inserting into and phase-separating within the lipid bilayers, which underlies both its penetration-enhancing effect and its potential to promote follicular plugging.
Lightweight, low-viscosity emollient with excellent skin feel, spreadability, and slip — reduces greasy after-feel compared to plant oils
Effective skin penetration enhancer for lipophilic actives (retinoids, vitamins, fragrance compounds) — commonly used in transdermal delivery formulations
CIR Expert Panel found safe as used across three assessment cycles (1982 original, 2005 re-review, 2015 amended fatty esters assessment)
- · Classified as highly comedogenic in rabbit ear assay (Fulton et al. 1984, PMID 6229554); widely regarded as a high-risk ingredient for acne-prone skin
Penetration enhancer: disrupts stratum corneum lipid lamellar structure (Engelbrecht et al. 2012, PMID 22614257), potentially increasing systemic exposure to co-formulated actives at higher use concentrations
CIR Quick Reference Table (12/2017, revised 07/2018) — ISOPROPYL MYRISTATE row: Finding=SQ, Detail='safe for use in cosmetics when formul…
“Isopropyl Myristate | SQ | safe for use in cosmetics when formulated to be non-irritating | JACT 1(4):55-80, 1982 confirmed 06/02 IJT 24(S1):63-67, 2005; IJT 34(Suppl.2):5-69, 2015”— QRT-122017revised072018.pdf, p. 65