You can use it to clean your body, your house, and even your pets.
Each product we feature has been independently selected and reviewed by our editorial team. If you make a purchase using the links included, we may earn commission.
Dr. Bronner's Castile Soap bottles on blue background

If you've ever strolled down the soap aisle at your supermarket, you know you have a lot of options. But I'm here to tell you: not all soap is the same. Castile soap is a vegan alternative to traditional soaps that can be used for everything from washing your face to washing your floors. Skeptical? Keep reading to find out why Castile soap is the all-purpose solution to your cleaning needs.

What Is Castile Soap?

This incredibly versatile soap is vegetable-based and made free of any animal fats and synthetic ingredients. It was first made in the Mediterranean before spreading throughout Europe, where it got the name Castile from the region of Spain.

Castile soap was traditionally made with olive oil, but today can be made with coconut, almond, walnut, castor, or hemp oils (like this best-selling soap from Dr. Bronner's). These oils give the soap its luxurious lathering and moisturizing properties.

In addition to these oils, Castile soap contains lye. When mixed with oil, lye creates soap molecules that, when mixed with water, create charged atoms that capture dirt.

Castile soap registers a whopping 8.9 on the pH scale. If you didn't pay attention in science class, here's a refresher: the pH scale is used to determine how acidic or alkaline different solutions are. Alkaline solutions are better for cutting through grease. Castile soap is right up there with baking soda, and it's even more alkaline than mild dish soap.

There's not much this soap can't do — use it to clean your body, your hair, your kitchen, and even your pets (but more on that below). Castile soap comes in both liquid and solid form (like Dr. Bronner's bar soap). And the best part is, it's natural, non-toxic, biodegradable, and affordable.

How Is It Different Than Other Soaps?

Traditional soaps, like most of the ones you see on supermarket shelves, often use tallow (a.k.a. animal fat). Castile soap uses vegetable oil, making it a vegan and biodegradable alternative to other soaps. For these reasons, it can be used as both a beauty product and a household cleaner. It's an all-purpose solution to all your cleaning needs that will save you space and cash.

Best Uses for Castile Soap

According to the experts at Dr. Bronner's, Castile soap has 18 uses (find the full list here). For some applications, you may need to dilute the soap with water. Here are some of our favorite ways to use Castile soap:

Use Castile soap for beauty and personal care. Castile soap is ideal for travel, because it's an all-in-one shower product. Use it as face wash, body wash, shampoo, and shaving cream. You can also add a tablespoon to a bowl of steamy water and breathe in to help clear congestion.

Use Castile soap to clean your house.

  • Hand wash dishes with pre-diluted Castile soap (1:10 ratio).
  • Add ½ cup soap to 3 gallons of water for mopping.
  • Make your own all-purpose cleaner by combining ¼ cup soap in a quart of water in a spray bottle.
  • Make a fruit and veggie wash. Mix 1 tablespoon soap with water in a bowl. Dunk and swish produce in the mixture and rinse until clear.
  • Spray your plants for pests by combining 1 tablespoon soap and 1 quart water in a spray bottle.

Use it for your furry friend. Yep, this non-toxic soap makes a great pet shampoo too, but stick to the unscented kind just to be safe.

Is There Anything I Shouldn't Use Castile Soap For?

The most important thing to remember is that you need to dilute the soap properly (refer to the package instructions). However, there are a few reasons you might want to avoid Castile soap. If you're using it for shampoo and you have color-treated hair, this can strip the dye.

You also don't want to mix acids like vinegar or lemon juice with Castile soap, as the two will counteract each other and cause a film to appear on whatever you're trying to clean. It's also important to remember that soap is a cleanser, and not a disinfectant, meaning it may remove some harmful bacteria, but it doesn't kill it.