How To Wash Your Hair With Castile Soap

Written by Ramona Sinha

Have you recently jumped on the no-poo bandwagon? Are you looking for shampoo alternatives? You can use castile soap.

It is a vegetable oil-based natural soap that is used in DIY recipes. While it is effortless to use, transitioning from shampoos to castile soap takes time. Castile soap is alkaline and may disrupt the scalp pH if not used properly. Don’t worry. Read this article to understand why you should switch to castile soap right away and learn the right way to use it for your hair.

What Is Castile Soap?

Castile soap is a multipurpose natural soap made from plant, nuts, and vegetable-derived oils. It originated in Castile, Spain, and was traditionally made using olive oil.

Castile soap contains lye (a metal hydroxide obtained from wood ash) and produces soap molecules. When you mix castile soap with water, it makes charged atoms that help dislodge dirt, grime, and grease. There are many benefits of switching from commercial shampoos to natural castile soap.

The Benefits Of Using Castile Soap For Hair

1. It Is Gentle

Castile soap is natural and has fewer ingredients in it. This oil-based, non-toxic soap cleanses gently and is extremely good for sensitive scalp. Castile soap is good for anyone with scalp issues (like eczema and dermatitis) or those looking for a non-drying cleanser for hair.

2. It Is Non-Irritating

Like commercial shampoos, castile soap does not contain fragrances, harsh detergents, and chemicals that might irritate the skin. Moreover, it preserves the natural oils of the scalp and helps maintain a healthy scalp. This may also help keep the hair follicles healthy and promote a healthy hair growth rate.

If you are looking for a non-irritating and gentle cleanser that will not damage and dry out your hair, you can use castile soap. However, dilute it before using. Here is how you can use castile soap instead of shampoo.

How To Wash Your Hair With Castile Soap

1. Dilute The Soap

Castile soap is alkaline and can affect your scalp pH. Hence, use a tiny amount of the soap and dilute it with purified water. To start with, follow a 1:2 ratio and mix a tablespoon of castile soap with 4 cups of purified water (each cup 100 ml). You can adjust the ratio as per your hair needs. However, do not use too much castile soap.

2. Use A Post-Wash Acidic Rinse

Castile soap is alkaline and should be followed with an acidic rinse to restore scalp pH. You can use lemon juice or apple cider vinegar rinse. Dilute ¼ cup of lemon juice or 4 tablespoons of ACV with 2 cups of water (100 ml each). Use this mixture as a post-wash rinse to wash your scalp and hair. Wait for a few minutes and rinse your hair with water.

3. Moisturize With An Oil

There is no need to use a conditioner. Instead, use any vegetable oil to lock in the moisture. You may use coconut, avocado, jojoba, argan, sweet almond, and apricot oils.

You can also mix castile soap with other ingredients to customize the natural shampoo. In the next section, we have shared a few recipes you may try.

DIY Castile Soap Recipes For Healthy Hair

1. Lavender Oil And Castile Soap Shampoo

Almond oil has emollient properties (1). Hence, it may help keep the scalp and hair moisturized. Lavender essential oil is used in aromatherapy to reduce stress and anxiety (2).

You Will Need

  • A bar of castile soap (melt and pour base)
  • 20-30 drops of lavender essential oil (for fragrance)
  • ½ teaspoon of sweet almond oil
  • 2 cups of purified water (100 ml each)


  1. Heat the castile soap in a double boiler until it melts. Let it cool down.
  2. Mix four tablespoons of the liquid castile soap with the water.
  3. Add the oils to the solution and mix.
  4. Pour the soap into a bottle and use it instead of a shampoo.

2. Peppermint Castile Shampoo

Peppermint oil promotes hair growth without irritating the scalp (3). It also adds a refreshing minty fragrance to the shampoo. Tea tree oil has antiseptic and antimicrobial properties (4). These can keep the scalp healthy.

You Will Need

  • 4 tablespoons of liquid castile soap
  • 10-20 drops of peppermint oil
  • 10-20 drops of tea tree essential oil
  • 200 ml of purified water


  1. Dilute the castile soap with water and mix the oils.
  2. Transfer the solution to a bottle.
  3. Wash your hair with the solution.

3. Clove Oil And Castile Soap Anti-Dandruff Shampoo

Research states that clove oil is effective against Malassezia and can help manage dandruff (5).

You Will Need

  • 4 tablespoons of liquid castile soap
  • 20-30 drops of clove oil
  • 200 ml of purified water


  1. Dilute the castile soap with water.
  2. Add the oil and mix.
  3. Store it in a bottle and use it for washing your hair.

Transitioning to natural castile soap from commercial shampoos is not easy. All hair types react differently. Initially, your hair may feel weighed down, and you may not get that squeaky clean feeling. However, this is temporary, and your hair needs time to adjust to the new routine.

Here are a few more pointers to keep in mind before you start using castile soap.

Things To Know Before Using Castile Soap

  1. Do Not Use On Colored Hair: Castile soap is an alkaline product and will strip your hair of its color.
  1. Do Not Combine Castile Soap With ACV And Lemon: Apple cider vinegar and lemon juice are acidic, while castile soap is alkaline. Acids and alkalis neutralize each other. This is not hazardous but will leave residue and an oily film on the hair.

To Conclude

If you are looking for chemical-free alternatives for your tresses, castile soap is your solution. It does not contain any harmful chemicals and can be customized to meet your hair care needs. You can use diluted castile soap or add some essential oils of your choice for fragrance. Try the recipes shared in the article, and we are sure your hair will love them.

Frequently Asked Questions

Does Castile soap damage hair?

No, diluted castile soap solution does not damage the hair.

How do you get castile soap residue out of the hair?

Use diluted lemon juice or ACV post-wash rinse to remove any soap residue.

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Ramona is a journalist-turned-content writer. She holds a Master’s degree in English Literature and has been writing for the digital world for over five years. She specializes in writing for Skin Care. She has done a certificate course titled ‘Dermatology: Trip To The Skin’, offered by Novosibirsk State University. She believes that beauty begins with a good skin care regimen and is on a mission to eliminate all toxins from her routine. She helps and guides readers in selecting products and ingredients specific to their skin type/issue. When Ramona is not working, her books and passion for music, good food, and traveling keep her busy.