Castile soap is a type of soap made of natural oils, such as olive oil, coconut oil, palm oil, hemp oil, or jojoba oil. Castile oil is a plant-based oil soap, which means that it’s vegan (contains no animal products), biodegradable, and more environmentally friendly than other soaps.
Castile soaps are extremely versatile. They can be used as personal and household cleaners and can even be used to wash pets.
Though the research on castile oil is limited, there are some indications that the soap can help with wound healing and that it can be helpful for people prone to dry skin. The most well-known castile soap is Dr. Bronner’s castile soap, which is sold in liquid and bar form.
Castile soap manufacturers often list many different uses and benefits of castile soap, including its antibacterial qualities, bug-repellent properties, and ability to clear nasal passages. However, little research exists about the benefits of castile soap for specific medical uses.
May Be Helpful for Dry Skin
Oil is one of the main ingredients in castile soap. One study published in the Indian Dermatology Online Journal listed olive oil-based castile soap as a good choice for dry skin. The idea is that the soap can cleanse your skin without drying it out.
Some people find castile soaps harsh on their skin because liquid castile soap is highly concentrated. Diluting it usually helps prevent any skin irritation.
May Help With Wound Healing
Vegetable oil-based soaps like castile soap might have antibacterial, antifungal, and antimicrobial qualities and may help with wound healing. Still, the research is mixed, and some of it is based on older data.
For example, one older study found that castile soap was significantly more effective at wound healing than saline solution. However, a more recent study found that saline solution was more effective than castile soap when cleaning open fracture wounds.
May Be More Environmentally Friendly
Many commercially sold soaps contain animal products, but castile soaps only contain vegetable oils. This makes them suitable for vegans or people who prefer not to buy personal care or household products made with animal ingredients.
Castile soaps are also more environmentally friendly. They don’t rely on animal product manufacturing, which has been linked with increased greenhouse emissions, deforestation, and pollution.
Vegetable oil-based soaps are also biodegradable, meaning the ingredients break down naturally without harming the environment.
How To Use
Castile soap is usually sold as a bar soap or in liquid form. The bar soap can be used to wash your body and face. The liquid form has more diverse uses.
Dilute First
Liquid castile soap is usually a highly concentrated soap and must be diluted before using.
If you use the soap to wash your body, apply a small amount to your hand and dilute it with water before turning it into a lather and washing yourself.
When using liquid castile soaps for other purposes, placing a small amount of the soap in a bottle and mixing it with water can be helpful. You can check the manufacturer's website or bottle instructions for proper dilution instructions based on how you use the soap.
Possible uses of castile soap include:
- Hand soap
- Body wash
- Shampoo
- Shaving "cream"
- Makeup remover
- Dishwashing soap
- Laundry detergent
- All-purpose household cleaner
- Pet cleaner
Some castile soap manufacturers recommend using castile soap to brush teeth, clear nasal passages, clean dentures or retainers, or repel insects.
It’s important to contact a healthcare provider before using the soap in these manners, as there is no published data on their safety and effectiveness when used inside the mouth (and possibly ingested) or to prevent insect bites.
There is no published data or guidelines from health organizations on the safety and side effects of castile soap. People who use it sometimes complain of irritated skin, though this is usually when using the concentrated liquid form without properly diluting it first.
There is also no published information about the use of castile soap in populations like pregnant people, breastfeeding individuals, older people, or children. These populations should speak to their healthcare provider before using a new personal care product.
Although most people aren’t allergic to castile soap, it’s possible to be allergic to any new ingredient you try, especially if you have sensitive skin. The American Academy of Dermatology Association recommends trying a "test spot" before using a new cleanser or other skin care product. Apply a small amount of the product to your skin (e.g., your arm) twice daily for about 7-10 days to see if you have any skin reactions.
Choosing a Castile Soap
All castile soaps are vegetable oil-based, but the type of vegetable oil can vary—for example, olive oil, palm oil, coconut oil, or jojoba oil. Some castile soaps have other ingredients, including essential oils and other scents. Look at ingredient lists carefully, and don’t use a product if it has any ingredients you are sensitive or allergic to.
As the Food and Drug Administration (FDA) points out, just because a product says it’s “natural” or “organic" doesn’t mean it’s safe or even 100% natural. The FDA doesn’t enforce the purity of products that claim to be all-natural or organic. They also don’t test or regulate soaps or other cosmetic products.
Consider checking to see if a third party tested the product you're interested in. This helps ensure product quality and safety.
Other factors to consider when choosing a castile soap include:
- How concentrated the soap is and how much dilution it requires before use
- Whether the soap is scented or unscented
- The cost of the product and how long you expect it to last
- Whether it has been approved for use by your healthcare provider, especially if you are using while pregnant or on a child
- Whether it’s a good match for your skin type or any skin conditions you have
- The type of packaging used by the manufacturer and whether it's environmentally friendly
Castile soap is a type of soap made of vegetable oils, such as olive oil, coconut oil, or jojoba oil. It is usually gentle on the skin and may have antimicrobial benefits. It’s an appealing soap for vegans or people who prefer not to use animal products for environmental or ethical reasons.
Because there is little published information about the safety of castile soap, it’s best to speak to your healthcare provider if you have any questions or concerns about using this type of soap.
