What to Look for in Bar Soap

Ingredients: As mentioned previously, most soaps use some form of surfactant to cleanse the skin, but since that can be drying, Aparovich recommends “choosing products formulated with gentler surfactants derived from glucose and coconut oil, such as Lauryl Glucoside or Coco Glucoside, to minimize the risks of cleansing-related dryness.” Both she and Chacon recommend shea butter, glycerin, coconut oil, and vitamin E for added moisture and gentle cleansing.

Face vs. Body: Like liquid soaps, some bar soaps are designated for the face and others for the body. “Most regular bar soaps are formulated for hand and body washing and aren’t tailored to the more delicate and sensitive skin on the face,” notes Aparovich. As a result, they can strip away moisture, compromise the skin’s barrier, and leave it feeling dry, tight, and irritated while also provoking blackheads and breakouts in people with oily skin as it will try to overcompensate lost moisture by intensifying sebum production.”

What to Avoid: If you have sensitive skin, it’s a good idea to check the ingredients on a bar soap to make sure there aren’t any “harsh preservatives like parabens and formaldehyde releasers, drying alcohols like ethanol and denatured alcohol, and allergenic fragrances like citral, coumarin, eugenol, and geraniol,” explains Aparovich. “These additives can stress the skin and trigger adverse reactions ranging from mild irritation and heightened sensitivity to allergies and inflammation.”

FAQ

What's the best way to use bar soap?

Aparovich says bar soaps can be more effective than liquid soaps because they have water-based, aka more diluted formulas. But you have to use them correctly. "Apply the product to wet skin after lathering it thoroughly in your hands or rubbing it onto a washcloth; it will promote more even distribution and smoother cleansing," she suggests. "Move from top to bottom of your body, gently massaging the lather into your skin. Pay extra attention to areas prone to sweat and bacteria buildup, like underarms and feet, while staying delicate to intimate areas, as these can be reactive to cleansing surfactants." She suggests using warm (not hot) water to prevent drying.

How do you store bar soap?

Chacon says it's best to store bar soap "out of the way of water and moisture. So if in your shower, make sure it's not soaking in water and is stored higher up in a cool, dry place." Aparovich explains why: "Soap ingredients can break down over time, which reduces their effectiveness and lifespan. A wet environment and direct exposure to moisture cause bar soap to become soggy and develop a slimy texture, accelerating degradation and provoking bacterial growth." A draining dish tray that's not near your faucet can help prevent this.

For this article, Byrdie interviewed these experts:

Valerie Aparovich is a biochemist and certified cosmetologist-aesthetician at OnSkin. Cosmetic formulations are the focus of Valerie’s professional expertise.

Dr. Anna Chacon, M.D., FAAD, is a board-certified dermatologist who offers care as a teledermatologist in all 50 states. She recently opened a brick-and-mortar practice in Miami, Florida.

Ally Hirschlag is an associate editorial director on Byrdie. An avid beauty-tester, Ally is always trying out new skincare products so she can share all-star performers with the Byrdie audience. She's tested cleansing balms, cleansing oils, body washes, shampoos, conditioners, and hand soaps, so she knows a thing or two about a good cleanser.