Isopropyl Myristate

Overview

Isopropyl myristate (IPM) is a synthetic ester made by combining myristic acid (a fatty acid found in coconut and other plant oils) with isopropyl alcohol. The result is a clear, colourless, low-viscosity liquid with no scent.

It is one of the most widely used cosmetic esters in mass-market formulations because it is cheap, stable, and exceptionally fast on the skin — it absorbs more or less immediately and leaves a dry, almost powdery finish. That makes it a favourite for products where you do not want any oil after-feel: deodorants, after-shaves, sunscreens, BB creams, and powder-finish lotions.

Shelf life is 3+ years stored cool and dark. The ester is very stable.

IPM has a reputation for being comedogenic — there is real evidence in animal studies and some clinical reports that high-percentage IPM in leave-on products can clog pores. For acne-prone facial leave-on products, use it sparingly or substitute with isoamyl laurate or another lighter ester.

What it does in a formula

The molecule is small and the chain is short, which is why IPM absorbs so fast. It also has notable penetration-enhancing properties — meaning it carries other ingredients into the skin alongside it. This is useful for active delivery but is also part of why high percentages can be irritating to sensitive skin.

In a formula it acts as a feel-modifier (dry, fast finish), a solvent for oil-soluble actives, a viscosity reducer, and a slip aid in roll-on products. It is found in essentially every commercial deodorant and most powdered foundation pressed cake.

It is not moisturizing or emollient in any meaningful way. Use it for feel and function, not for skin benefit.

How to use

Add to the oil phase. Tolerates heat-and-hold to 80 C. Can be added in the cool-down without issue.

Usage rates by product type:

• Deodorants and antiperspirants: 5-15%
• After-shave balms: 3-10%
• Sunscreens (chemical filters): 5-15% (carrier and feel modifier)
• Foundations and BB creams: 5-20%
• Pressed powders: 1-5% (binder)
• Body lotions for fast finish: 2-10%
• Hair oils (lightweight): 3-10%

Best for / Worst for

Best for: deodorants, after-shaves, fast-finish sunscreens, foundation and pressed powder formulas, anywhere you need a fast dry feel and chemical predictability.

Worst for: acne-prone facial leave-on products (comedogenic risk), sensitive skin formulas (penetration enhancement can mean irritation), clean-beauty positioning (synthetic), rich moisturizers (no emollient value).

Common pitfalls

Comedogenic risk. IPM is on most “comedogenic ingredient” lists for a reason. Cap at 5% in leave-on facial products, and consider isoamyl laurate or caprylic/capric triglyceride as a swap for acne-prone formulas.

Overuse in fragrance. Because IPM dissolves fragrance compounds so well, it is tempting to use it as a body spray base. At high percentages on broken or sensitive skin, irritation is possible.

Confusion with isopropyl palmitate. Sister ester (palmitic acid + isopropyl alcohol), slightly heavier feel. Similar function, slightly less penetration-active.

Substitutes

• Isopropyl palmitate — slightly heavier, very similar role.
• Isoamyl laurate — natural-positioned, similar dry feel, less penetration enhancement.
• Coco-caprylate — natural ester, dry finish, gentler on acne-prone skin.
• Caprylic/capric triglyceride — different chemistry, similar lightweight use.