What's the Difference Between Body Wash, Bar Soap, Shower Gel, and Castile?
Bar soap and body wash are both cleanser where one is solid and the other is a liquid. "Beauty bar" usually points to a synthetic-detergent cleanser. "Castile" points to soap made from vegetable oils. Body wash and shower gel are closely related liquid cleansers, with texture and fragrance often separating the names.
The legal meaning of soap is narrower than its everyday meaning. It helps explain why a package may say beauty bar, cleanser, or wash instead.
Dove Sensitive Skin Beauty Bar
What Counts as Soap
The FDA defines soap by what provides the cleaning action. To fit that definition, cleansing must come from alkali salts of fatty acids, the compounds produced when fats or oils are combined with lye. That reaction is called saponification. The product must also make cleaning-only claims.
A cleanser that relies on synthetic detergents doesn't meet the legal definition of soap. If a product claims another cosmetic purpose, such as moisturizing or deodorizing, the FDA regulates it as a cosmetic even when its cleansing ingredients come from saponified fats.
This is why some familiar bars avoid the word soap. Dove Sensitive Skin is labeled a beauty bar and "More Moisturizing Than Bar Soap." Its cleansing formula places it in the synthetic-detergent, or syndet, category.
Body Wash, Shower Gel, and Liquid Soap
Most body washes and shower gels use synthetic detergents. Both are liquid cleansers, and no regulated definition separates the two names.
Shower gel tends to be thicker, clearer, and more heavily fragranced. Some gels are firm enough to hold their shape on a loofah. Body wash is often thinner or creamier and more likely to carry moisturizing claims based on ingredients such as glycerin or oils, although brands use body wash and shower gel interchangeably.
Liquid soap is less predictable as a label term. A true liquid soap can be made with saponified oils, as liquid castile is. Many products sold as hand soap or hand wash use synthetic detergents instead, so the front label doesn't settle the question.
Turn to the ingredient list when the distinction matters. Names such as sodium lauroyl isethionate or cocamidopropyl betaine indicate synthetic detergents. Sodium tallowate, sodium cocoate, sodium olivate, and "saponified" oils indicate true soap ingredients.
What Bar Labels Tell You
Beauty bar, moisturizing bar, cleansing bar, and gentle skin cleanser usually identify syndet bars. These products often combine synthetic detergents with emollients and are formulated at a lower pH than traditional lye soap. A reviewer of Dove Sensitive Skin, headed "Leaves your skin moisturized," writes that it "makes my skin feel soft and moisturized after using."
A deodorant bar is intended for odor control during washing. It commonly uses stronger fragrance and may include an antibacterial ingredient. Irish Spring, Safeguard, and Dial sell products in this group, which may be true soap or a blend of soap and synthetic detergents.
Irish Spring Deodorant Soap Bars Aloe
Castile and pure soap labels point toward saponified plant oils and a relatively short ingredient list. Kirk's Original Coco Castile is a coconut-oil bar sold in this category at Safeway.
Kirk's Original Coco Castile Bar Soap
Antibacterial Soap and the 2016 Rule
In 2016, the FDA barred 19 active ingredients from over-the-counter consumer washes used with water. Triclosan and triclocarban were among them. The agency said manufacturers hadn't shown that the ingredients were safe for long-term daily use or that they prevented illness better than plain soap and water. The rule took effect in 2017.
It covers liquid, foam, and gel hand soaps, along with bar soap and body wash. Hand sanitizer, hand wipes, and antiseptic products used in healthcare settings fall outside this rule.
Antibacterial bars and washes are still sold. Current products use other permitted active ingredients, commonly benzalkonium chloride or chloroxylenol, and the antibacterial drug claim requires a Drug Facts panel. One review of the Dial antibacterial bar, headed "Good antibacterial soap," notes "great rinsability with little to no drying."
Dial Complete Gold Antibacterial Bar Soap
For everyday home washing, the FDA says plain soap and running water is one of the most effective ways to reduce the spread of germs. The agency hasn't found evidence that consumer antibacterial soap works better for that purpose. Antibacterial products are still on the shelf and remain a legitimate choice.
What Castile Soap Is
Castile is true soap made from vegetable oils instead of animal fat. The name comes from the Castile region of Spain, where it originally referred to olive-oil soap. Modern castile products may use olive, coconut, hemp, or other plant oils.
"Pure castile" means the cleansing comes from saponified vegetable oils. Liquid versions are concentrated and can be diluted for washing the body or hands as well as for general cleaning, giving them a broader range of uses than a body-specific wash.
Safeway's Open Nature line carries Pure Castile Multi Purpose Soap in peppermint and lavender. One reviewer, under the headline "Versatile and economic product," lists the uses: "Shampoo and body wash. Gentle and invigorating. Also works great for cleaning counter tops."
Open Nature Pure Castile Multi Purpose Soap with Peppermint Oil
True soap has a higher pH than many syndet cleansers. In hard water, it can leave a soap-scum film and may feel drying to some people. Those characteristics apply to castile along with other true soaps.
Choosing a Cleanser at Safeway
For dry or sensitive skin, look for "fragrance-free" or "sensitive skin," often on a syndet cleanser with added emollients. Fragrance is a common irritant. "Unscented" can still mean that masking fragrance was used to cover the smell of other ingredients, while "fragrance-free" means none was added.
Deodorant bars and washes use fragrance, and sometimes an antibacterial active, for odor control during washing. If you specifically want an antibacterial product, the Drug Facts panel identifies the active ingredient.
Castile suits shoppers looking for saponified plant oils, a short ingredient list, or a concentrated soap with body, hand, and household uses. Its higher pH and behavior in hard water may matter more than whether it comes as a bar or liquid.
Formula matters more than format. A moisturizing beauty bar and a creamy body wash may have more in common with each other than either has with a traditional soap bar.
Common Questions
Is bar soap or body wash better for your skin?
Neither format is always better. A bar may be a traditional soap or a syndet beauty bar, and a bottled cleanser may be a creamy body wash or true liquid soap. Added emollients, fragrance, and pH can affect how either one feels, so check the formula and label claims instead of choosing by shape alone.
How can I tell whether a product is true soap?
Read the ingredient list. True soap starts with saponified fats or oils, listed under names such as sodium tallowate or sodium cocoate. A syndet cleanser starts with synthetic detergents, including sodium lauroyl isethionate or cocamidopropyl betaine.
What's the difference between body wash and shower gel?
The distinction isn't regulated. Shower gel is usually thicker and more fragrance-forward, while body wash tends to be creamier and more likely to carry a moisturizing claim. Brands may use either name for a similar liquid cleanser.
Is fragrance-free the same as unscented?
No. Fragrance-free means no fragrance was added. An unscented product may still contain masking fragrance to cover the smell of its other ingredients.
Is antibacterial soap better for everyday washing?
Not according to the FDA's assessment of everyday home use. The agency says washing with plain soap and running water works as well for everyday cleaning. Today's antibacterial washes use permitted active ingredients and carry a Drug Facts panel.
What is castile soap?
Castile is true soap made with vegetable oils. It began as olive-oil soap from Spain's Castile region, but the name now includes soaps made with other plant oils. Concentrated liquid castile can be diluted for body, hand, and household cleaning.