Isopropyl Myristate Is the Moisture-Locking Ingredient You've Never Heard Of

It's so much more than an emollient.

bottle and dropper

Liz deSousa for BYRDIE

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 is unique in that it's able to enhance the penetration of other ingredients, not to mention it's essential when it comes to formulating and creating products that are cosmetically elegant. Ahead, dermatologist Sapna Palep, MD, of Spring Street Dermatology in New York City, dermatologist Dan Belkin, MD, of Laser & Skin Surgery Center of New York, and Sheel Desai Solomon, MD, a dermatologist in Raleigh/Durham, North Carolina explain what sets this ingredient apart from its moisturizing counterparts.

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).

Benefits of Isopropyl Myristate For Skin

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.

Softens the skin: As an emollient, it also helps soften and smooth dry skin, which is why this is a choice ingredient for those with dry or flaky skin.

Enhances the penetration of other ingredients: The exact mechanism by which this works isn't fully clear, but it's thought that isopropyl myristate changes the structure of the stratum corneum, the most external layer of the skin, making it easier for active ingredients to absorb, explains Belkin. In turn, this can make the skincare you're using more effective.

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.

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.

The Best Products With Isopropyl Myristate

Vaseline Intensive Care Cocoa Radiant Spray Moisturizer $6

Non-greasy and non-sticky, Solomon is a fan of this formula. With micro-droplets of Vaseline, it helps heal dry skin, though still feels lightweight. Isopropyl myristate aids in those hydration benefits, plus, the, "non-aerosol, continuous spray lotions dispenses evenly for all-over coverage," she says. Not to mention, it takes only seconds to apply—a win in our book.

RoC Retinol Correxion Anti-Aging Eye Cream $17.50

Palep recommends this eye cream for retinol newbies, since it's gentle yet still works. "I think it's the most effective over-the-counter retinol eye cream," she says. Credit isopropyl myristate for helping to improve the penetration of the proven wrinkle-fighting, line-smoothing ingredient.

Peter Thomas Roth Neuroliquid VoluFill Youth Serum $120

There's no shortage of youth-boosting ingredients in this serum. We're talking a complex of five peptides that improve skin thickness, three different types of strengthening collagen, and hydrating hyaluronic acid. Isopropyl myristate acts as a performance enhancer, boosting the penetration of all of these while making the texture feel cosmetically elegant.

Melanie Simon Skincare Serum C $200

Isopropyl myristate is one of only five ingredients in this serum. It boosts the efficacy of the star of the show: 15 percent of a stabilized version of skin-brightening vitamin C. Top tip: Allow it to soak into skin for five to 10 minutes, transforming from an oily to dry feeling, before layering any other products on top.

erno laszlo
Erno Laszlo Active Phelityl Cream $96

When you need an intense, heavy-hydrating moisturizer, reach for this rich formula. Specially formulated to protect your skin for up to 24 hours, isopropyl myristate is one of the ingredients that helps strengthen the skin barrier to lock in moisture. It's no surprise that we ranked it one of the best moisturizers of the year.

Skinceuticals Hydra Balm $23

For ultra-dry or compromised skin (think post-procedure or when you're dealing with flaking and cracking), this healing balm is a prime choice. Emollients such as squalane—and, you guessed it, isopropyl myristate—hydrate and soften skin, while petrolatum, an occlusive ingredient, seals in moisture.

Versed Keep It Supple Body Oil $15

Made with coconut, sweet almond, and sunflower seed oils, this body hydrator packs a nice hit of moisture, and isopropyl myristate keeps the formula from ever feeling greasy, leaving skin silky and soft. While it contains no artificial or added fragrance (a win for those with sensitive skin), it does contain ylang ylang oil, which makes for a subtle-yet-sophisticated light floral scent.

Article Sources
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  1. National Library of Medicine. PubChem Compound Summary Isopropyl myristate. Updated March 20, 2021.

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