A Natural Vegetable-Based Soap With Multiple Uses
Castile soap is a vegetable-based soap that is free of chemicals, other synthetic ingredients, and animal products. It can be used to wash your skin, hair, clothes, and more. It is also hypoallergenic, making it an ideal option for people with sensitivity to harsh soaps and cleansers.1 One of the most well-known brands of Castile soap is Dr. Bronner's.
This article describes the various applications, benefits, and risks of Castile soap when used for personal care, household cleaning, or the treatment of certain medical concerns.
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What Is Castile Soap?
Castile soap originated from the Mediterranean region around Castile, Spain in the 12th century. It was originally made from pure olive oil. Today, it is made with a variety of plant-based oils, including hemp, coconut, avocado, and almond oil.2
While Dr. Bronner's is probably the most popular brand of castile soap, there are several others (including Kiss My Face and Kirk's) available in bar and liquid form. Some products are scented with essential oils, and all are non-toxic and biodegradable (making them environmentally friendly).
Choose a soap that meets your preferences in terms of scent, form, (bar or liquid), packaging preferences
Check for certifications such as USDA Organic, Fair Trade, or Cruelty-Free if these are important criteria for you.
Uses of Castile Soap
There are many different applications for castile soap, from washing your skin and hair to cleaning your clothes, dishes, and surfaces.
Shampoo
Castile soap lathers easily. And because of the fat content in the oil it is made from, it may leave your hair feeling smoother and more conditioned than some chemical-based shampoos.
Castile soap can also be used to bathe dogs. Any of the Dr. Bronner's fragrances are safe; if your dog has sensitive skin, the unscented baby formula may be best. A squirt of soap diluted with water should do the trick.3
In contrast, many shampoos on the market contain a surfactant, most often sodium lauryl sulfate or sodium laureth sulfate, that traps oils and contaminants and removes them from your hair. It also serves as the foaming agent in shampoo. As effective as these ingredients are, they can sometimes leave your hair feeling dry and brittle.4
Face, Hand, and Body Soap
One of the problems with many bar soaps is that they are drying and can undermine the barrier function of the skin. They do so by stripping the natural oils (sebum) that protect the skin from microorganisms, toxins, and sun exposure.5
Castile soap is milder than many bar soaps. It can clean the skin while replacing some of the lost sebum with vegetable oil. Castile soap is safe to use around the genitals, but you may want to choose a mild or unscented formula. Always dilute liquid formulations as instructed.
Castile soap may also be an option if you have acne, as the oils these products contain have antibacterial properties.6
Makeup Remover
Traditional makeup removers rely on a combination of solvents to remove makeup. They can either be water-based or oil-based (often with silicone oil as the main ingredient).
Castile soap may be an appealing alternative. You can add a drop or two to some tap water and use a cotton ball to remove foundation and eye or lip makeup. Depending on the formula, castile soap is much less astringent than traditional makeup removers so it should not cause skin irritation or dryness.
Shaving
Vegetable oils can be beneficial to the skin, although those that contain high concentrations of oleic acid can cause skin inflammation.7
As shaving can cause local skin inflammation, select castile soaps with lower concentrations of oleic acid. These include options made with coconut oil, safflower oil, soybean oil, or sunflower oil.8
Check the product label if you intend to use it for shaving or already have an inflammatory skin condition like eczema or psoriasis.
Simply lather up some in plenty of water and apply the foam directly to the skin. The natural oil content can help lubricate the skin.
Deodorant
Rather than stopping sweat like antiperspirants, many chemical deodorants work on odor-causing bacteria on the skin with antibacterial ingredients such as triclosan and chlorhexidine. These ingredients have come under scrutiny in recent years due to concerns about their long-term safety.9
According to the Food and Drug Administration (FDA), regular soap is just as effective in killing common bacteria as soaps with triclosan or chlorhexidine.9
Castile soap offers a good alternative to commercial deodorants in that it is not only natural but contains ingredients like hemp oil or almond oil, which have potent properties that kill odor-causing bacteria.1011
The Hidden Risks of Antibacterial Soap
Wound Cleaning
Castile soap has been studied extensively for its potential benefits in wound cleaning. It is sometimes used to irrigate wounds caused by a compound bone fracture, often in combination with a saline solution and the ammonium-based compound benzalkonium chloride.12
After wound closure and the application of topical antibiotics, this irrigation method was shown to shorten hospitalization stays and speed wound healing when compared to the use of normal saline and a dressing with betadine solution.12
Fecal Impaction
Fecal impaction occurs when hardened stools collect in the lower intestine (colon) and become difficult to pass. An enema and stool softener are often used to help ease stool from the rectum without injury.13
A 2016 study from the Baylor College of Medicine in Houston found that a soap suds enema made from diluted castile soap was not only effective but safe in children with fecal impaction.14
However, it is important to consult with your healthcare provider before trying this.
Household Cleaning
In addition to being part of your personal care routine, a bottle of castile soap can also be handy for cleaning around your home.
Castile soap can be used in numerous ways:
Dishwashing soap
Laundry detergent
All-purpose cleaner
Bathroom cleaner
Floor cleaner
Window cleaner
Produce wash
Pet wash
To ensure optimal results, always follow the manufacturer's instructions on the product label.
Benefits of Castile Soap
Here are just a few of the potential benefits of castile soap:
Versatility: There are many ways to use castile soap around your home and on your body.
Low cost: Compared to other beauty and cleaning products, a bottle of castile soap is affordable and cost-effective. You can get a good-sized bottle for under $10.
Animal-free: Many people who live a vegetarian or vegan lifestyle prefer not to use any products with ingredients that come from animal sources. Pure castile soap is vegan.
Hypoallergenic: Pure castile soap is hypoallergenic, which means it's less likely to cause allergic reactions than other types of soap. Check that you are not allergic to added ingredients such as fragrances or essential oils.1
Pet-safe: Some cleaning products are harmful to pets, but pure castile soap is non-toxic and safe to use on surfaces where pets walk. With that said, added essential oils can irritate a pet's skin, so read the product label.15
Environmentally friendly: Pure castile soap has a very small impact on the environment since it doesn't contain additives, preservatives, artificial coloring, or other chemicals commonly found in other soaps.
Risks and Considerations
Although castile soap is an effective, all-around soap and cleaning agent, it is not without its shortcomings. However you decide to use it, you need to use it correctly.
Here are a few things to keep in mind:
Soap residue: Castile soap can leave a residue on shiny or hard surfaces, especially when it's used with hard water.
Incompatibility with acids: Since Castile soap is alkaline, you shouldn't mix it with acidic substances like lemon juice or vinegar. This can neutralize its effects.
Needs dilution: If you don't dilute Castile soap with water, it can be very concentrated. This can make it hard on surfaces and the skin.
Not for color-treated hair: If you have dyed hair, castile soap can strip some of the color from it due to its alkaline properties.
May harm household plants: While some natural cleansers are safe for plants, the alkaline properties of castile soap make it unfriendly to plants.16
Expiration: Castile soap can last a long time, but it won't last forever. If you have a bottle stored in your cabinet, keep an eye on the expiration date.
Summary
Castile soap is a safe, plant-based cleaner you can use around your house and as part of your personal care routine. With that said, it needs to be used correctly, adhering to the manufacturer's instructions, to ensure it is appropriately diluted and/or applied.