Isopropyl Myristate
You've most likely heard of moisture-enabling ingredients glycerin and hyaluronic acid, but we're willing to bet you've never heard of isopropyl myristate. Though, if you were to do a quick scan of the skincare and personal care products currently in your bathroom, we're also willing to bet that it's in a large percentage of them. An emollient ingredient, isopropyl myristate helps to strengthen the skin barrier, ensuring that moisture stays locked in. But, unlike other emollients, the benefits don't stop there.
ISOPROPYL MYRISTATE
TYPE OF INGREDIENT: Emollient, though it also acts as a thickening agent and lubricant in beauty products.
MAIN BENEFITS: Strengthens the skin's natural moisture barrier to lock in hydration, enhances the penetration of other ingredients, thickens formulas, and makes those with a high oil content feel silky rather than greasy.
WHO SHOULD USE IT: Isopropyl myristate is ideal for anyone with normal to dry skin looking for moisturization benefits, according to Palep.
HOW OFTEN CAN YOU USE IT: For the best results, follow the directions on the product it's found in, though daily or twice daily use is generally fine.
WORKS WELL WITH: Isopropyl myristate works well with an assortment of active ingredients, says Solomon, which is why it's found in so many different types of products and formulas.
DON'T USE WITH: Because it does enhance penetration, it’s important to assess the other ingredients in the formula and whether this increased penetration can cause unexpected side effects such as irritation, cautions Palep.
What Is Isopropyl Myristate?
A synthetic oil, isopropyl myristate is made up of isopropyl alcohol—a propane derivative—and myristic acid, a naturally-occurring fatty acid, explains Palep. While it's not necessarily a solo skincare star that you'll find touted as a hero ingredient, it's a popular cosmetic ingredient in a wide array of beauty products, found in everything from aftershave to anti-perspirants to anti-aging creams. Why so popular? First, there are the formulation benefits. "By thickening formulas, it gives products a denser texture and also improves the overall texture of those with a high oil content to be silky rather than greasy," says Palep.
And while that's a major win for the labs and scientists making your beauty products, it does have skincare benefits for you, too. While there are plenty of emollients on the market, isopropyl myristate has the added benefit of enhancing the penetration of other ingredients (more on that below).
Strengthen's the skin barrier: Isopropyl myristate keeps the outermost layer of the skin strong and intact. Think of the skin barrier as being made up of bricks and mortar: the cells are the bricks and all of the lipids (fats) are the mortar. Isopropyl myristate is that mortar, filling in cracks in between the skin cells so that moisture can't escape.
Side Effects of Isopropyl Myristate
There's one big caveat with this ingredient: "The one documented drawback to isopropyl myristate is that it can clog pores," notes Solomon. Translation: Those with acne or who are prone to breakouts should steer clear. And while it's generally a good thing that it enhances penetration of other ingredients, this can also prove to be a double-edged sword. "Because it is a penetration enhancer, it may make irritation from other active ingredients more common," cautions Belkin. He also points out that those with rosacea or particularly sensitive skin should be extra cautious about formulas that contain isopropyl myristate along with powerful actives that can be irritating to begin with, such as retinoids and acids.
And, as with any other ingredients, there's also a risk of allergic reaction.1
How to Use It
Because it's found in so many different products and formulations, your best bet is to follow the instructions on any particular product. Still, you're likely to be limited more by the actives in a product than minor ingredients like isopropyl myristate, notes Belkin.