How to Wash Your Hair with Castile Soap

In the world of natural beauty, changing up your hair care routine can be one of the toughest to achieve. But that’s not to say it’s not worth the effort.

Some of you may remember my honey hair-washing experience. Yes, I washed my hair with honey…for an entire month. I gave it an honest go, but my hair just never felt clean. Now I’m onto something new — castile soap.

Castile soap is a natural, vegetable-oil-based soap that has many, many uses. Surely you’ve come across Dr. Bronner’s famous “18-in-1” castile soap that boasts a multitude of uses, like washing your hands/face/body/hair, brushing your teeth, cleaning your dishes, washing your windows, scrubbing your bathroom and more.

While I’m no expert in washing hair with castile soap, I’ve picked up quite a few tips along the way:

Leave yourself some extra time.

The process is actually super simple, but it does require a few extra minutes of prep. I make my washing and rinsing concoctions just before getting into the shower, but you could make in advance, if that’s easier! Being organized is key, so store all of your materials in the same area if possible.

Dilute, dilute, dilute.

Castile soap is extremely alkaline, which means that it can quickly disrupt your hair’s natural pH balance if you use too much. Trust. I’ve made the mistake. Dilute your soap in purified water. I know it’s way easier to use water straight from the tap, but even the cleanest tap water is likely to contain enough chlorine and heavy metals to be harmful to your precious locks. The necessary ratio of soap to water will differ from person to person (and even from day to day) but, with a little bit of experimenting and patience, you’ll quickly become a pro. I use a ratio of 1 tablespoon castile soap to 2 cups purified water. Start with that, and experiment from there.

Get a squeeze bottle.

I use glass jars, personally, but this requires really swift movements in order to pour the mixture exactly where I want it. It might be helpful to use a squeeze bottle instead – especially when you’re just starting out. Look for BPA-free. ;)

Follow with an acidic rinse.

This step is crucial! I repeat: CRUCIAL. Since castile soap is very alkaline, it requires a follow-up rinse of something acidic like lemon juice or apple cider vinegar to restore the pH. I’ve used both, and they’re both excellent! Again, dilute the acidic agent in purified water. I do about ¼ cup of lemon juice or ACV to 2 cups water, but again, this is up for experimentation. If you’re using apple cider vinegar, your hair may retain a bit of the smell, but this will likely dissipate more and more with each wash, until you can’t smell it at all. I also like to add in a few drops of essential oil – lavender has been my recent go-to. After you rinse, run cold water over your hair to seal it. Word to the wise: Be sure not to mix your acidic agent and castile soap – they’ll cancel each other out!

Finish with an oil.

Since we’re no longer using conditioner, we should consider another way to incorporate moisture. Oil to the rescue! The choice is up to you and your personal preferences: avocado, coconut, argan, jojoba, almond, apricot… Steer clear of unnatural additives. 

Use a natural dry shampoo.

One of the reasons I love washing with castile soap is — I don’t have to wash my hair as often as I used to. All I need is a little dry shampoo to keep it looking fresh.

Be open to experimentation.

Going all natural with hair care is not an easy feat. Be open to experimenting with different ingredients, different brands and different ratios – and most importantly, do it all with love. Remember why you decided to do this to begin with: because you care! About the environment, and about yourself.


+ All FP Beauty + Wellness here!



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8 years ago

Hey! I love your hair color and length and I don’t know if it’s the light/picture but the overall finish doesn’t look great to me. It seems to lack shine and body (the hair looks very thin/stringy at the bottom) so I’m not sure about the routine you describe. I really don’t mean to criticize your hair, I’m sure it’s very nice and probably different in real life but the pics don’t make me want to try the routine :(

8 years ago

as much as i’d love to be using castille soap, it’s a no no for coloured hair :(
on lisa bronner’s blog she states: “One disclaimer – don’t do this on colored hair. The alkalinity of the soap opens up the hair follicles, where the color resides. The color will drain out and fade quickly. Colored hair needs acidic products only. (Soap, by nature, cannot be acidic. Only detergents (shampoo) can be.)”


8 years ago

My mother washed my hair with Castile soap when I was a child, and rinsed with lemon. She used the bar directly. Your post brought back a lot of memories! Now that I’m an old lady, I find my scalp is dry and itchy lately, so perhaps Castile is the answer.

8 years ago

Hair on fleek!

8 years ago

i’ve been on the natural haircare path for a month now and it’s been great! i haven’t tried castile soap, but i rinse with acv each time i wash my hair! (i’ve been experimenting with honey when it feels dry or clay when it’s oily) my hair is thicker, healthier feeling, and less frizzy than it’s ever been.
if you’re starting the natural hair game, whether that be castile soap, baking soda+acv or other methods, I would advise, from personal experience, to make sure and use a good clarifying shampoo before you begin your journey! otherwise you’ll be working with all the old buildup of your previous shampoos, conditioners, and hair products.

8 years ago

I have been washing with castile soap for about a year now. And I use coconut oil as a conditioner. I absolutely love it. It makes my hair feel so amazing, its so affordable, and it last longer then bought shampoo.

4 years ago
Reply to  Hilal

how do u apply the cocunut oil without your hair being oily and rinse it all out without it being oily

8 years ago

I always dye your hair, do hair, sometimes hair extension, usually her hair conditioner is also different, so now my hair becomes dry rough, read your article, I’m going to try to do more hair care I hope it can be restored.

8 years ago

I have tried different methods of natural hair washing but my hair never felt clean, but I have come across these amazing natural shampoo bars and they are amazing, I will never use anything else again! It’s from Beauty and the Bees a little shop in my home state Tasmania, Australia. They also have an online shop and people all over the world have given rave reviews. I have naturally curly/wavy hair and the nettle one is fab, also the beer shampoo gives extra body and bounce. You can rinse with Apple cider vinegar as a conditioner. They are full of natural ingredients like olive oil, coconut oil, castor oil, honey and all sorts of herbs and great things for hair growth and health! And are quite inexpensive at $12 au a bar. I can’t be more positive about these shampoos, if you like shampoo bars and natural products you will love these!

8 years ago

Very nice blog i loved it, and get huge things. You also try home remedies tips for hair and its easy to use at home.

8 years ago

Castile soap is something new for me. I normally use hair loss concealer on my thinning hair which are working fine for me. I would suggest others to use them instead of going after any medications.

8 years ago

Just a thought: go ahead and mix Castile soap in purified water, but you’re still rinsing and washing in straight up tap water. So you don’t really have to go the extra mile (and dollar) using purified water.

7 years ago

Sorry – I gotta disagree with “so” who left the first comment.
I think this blogger’s picture above looks amazing. Her hair is expressing itself with texture and bounce. To me, it looks very lively.
Part of realizing natural beauty is being able to recognize health. This sometimes means a little re-envisioning of beauty too. Do you think those goddamn Pantene hairstyles are what we’re trying to achieve anyway?

7 years ago

This is something new for me. castile soap is much easier to use. You can use it for oily hair.

7 years ago

Really, really excited to try this castile soap for shampoo! I have been all natural with my hair care for five months now as an attempt to reverse pretty bad hair loss, unfortunately I found out today that the all natural shampoo I have been using is actually rated at a high hazard toxicity by the EWG… Not so natural after all. So this blog post is giving me hope and encouragement during this speed bump.
I have been loving cocoa powder as dry shampoo for my brown hair! I think I might try mixing it with arrowroot powder to see what it does because you make it sound so great! I use castor oil every day as my conditioner and I’m looking forward to interchanging it with avocado and coconut oils.
Thank you for your blog posts, throughout my journey and all the hours of research I have been doing I have not found anything this amazingly resourceful.
Much love xox

7 years ago

When you say finish with an oil how to apply the oil? While you’re still in the shower on your wet hair and give it a rinse after. Or on towel(t-shirt ;) ) dried hair or on completely dry hair?


7 years ago

I decided to ditch commercial shampoos and conditioners about 2 months ago. I started with a blend of coconut milk and jojoba oil and other ingredients but it left my hair a huge greasy mess! I then switched to Baking Soda and a ACV rinse and immediately the greasiness was gone. However after about a month of that my hair just didn’t feel like it was actually being cleaned. I have been trying Castille soap and an ACV rinse for two weeks now but my hair still feels really greasy. Anybody have some tips? Or would my hair still be in the process of getting use to it? I hope this is something that won’t happen everytime!

7 years ago

Great article,i am surely gonna take in note and after that i want to suggest the product i am using, strengthen grow restore conditioner , its really effective

julia marie
7 years ago

This is something new for me. castile soap is much easier to use. You can use it for oily hair. because i am using jamaican black castor oil from long and its really effective.

7 years ago

I’ve been using Dr. Bronner’s unscented castile soap for shampoo for a few days now as I have eczema and my scalp and ears can get suuuuper itchy. This has seemed to quiet the itching on my scalp quite a lot. I use a little and rub the suds on my ears also. I was going to experiment with using some essential oils mixed in as well, and I often put argan oil in my hair after rinsing as my hair has always been dry and fragile.

7 years ago

Please make sure if you have eczema or dermatitis (like me) to ALWAYS finish with a diluted ACV (1TSB + 1cup water) as Castile shampoo is highly alkaline with a pH of 9.
Skin has a pH of 5.5, so a diluted mix of ACV and water poured over the scalp and combed through the hair will do the trick. Do not rinse.
Be careful if you suffer from these skin conditions as alkalinity is a disaster for people like us!

7 years ago

I washed my hair in Dr Bronners and used a normal condioner after. I didn’t know about the necessity of an an acid rinse. And we have very hard water here….My hair feels TERRIBLE. What should I do now? Help!

Crystal Zoblisien
7 years ago

Omg so glad I found this. Just bought a bottle of this soap and was planning just using it straight up and decided to do some research. Glad I did or I may have wreaked my hair! Thanks for being detailed. It helped me a lot!

7 years ago

I just bought a bottle of Dr Bronner’s and have used it the past two days and my hair feels terrible! These are the first two days of my natural hair care journey and I’m realizing I jumped the gun without reading anything prior to starting- whoops! I didn’t dilute it and my hair feels like an absolute mess! It feels like I’ve never washed my hair in my life. It feels so filmy and like there’s a ton of build up in it, like I’ve put product in my hair without ever washing it. It’s so gross! What should I do? Spend a long time in the shower just rinsing everything out and restarting with a super diluted mix this time followed by ACV rinse?
Does the ACV rinse help with tangles? If not, what do I do about tangles? My hair is pretty fine and relatively thin (pretty typical blonde hair) so it tangles easily. Is this the purpose of the oil after the shower? Help! :)

Sandra Jensen
7 years ago
Reply to  Megan

Megan – what I did was apply an olive oil and egg yolk treatment to hair I rinsed in bottled water (i.e. not hard water), added a bit of normal conditioner, left it on a couple of hours and then washed with normal shampoo and conditioner and more bottled water and about a tablespoon of ACV added to the last rinse. My hair went back to normal. I’m afraid I’ve not wanted to risk trying again with Dr. Bronners.

7 years ago

@ 23.Megan: You are right about needing to dilute Dr. Bronner’s liquid soap. You are right about the absolute necessity of following the diluted Dr. Bronner’s soap wash with an acidic rinse. Yes, ACV rinse will help with detangling, smoothing, and conditioning. However, if you have only recently stopped using store-bought shampoos and conditioners, or are still using them, your hair and scalp will have build up of the proteins, polymers, and silicones, etc from those products. Your hair and scalp may be stressed from the detergents in shampoo. It takes some people a few months to detoxify their hair and scalp from the build up. And then the scalp may be in oil-overproduction mode to compensate from being stripped by detergent shampoos. So there may be a greasy buildup. Cleansing with baking soda (1 tblsp. in a cup of water) and following with ACV rinse can help speed up the process. Baking soda is a great clarifier but i found it to be too harsh for my hair for the long term. Also helpful to clarify and detoxify: clay hair and scalp masks. And time will help as the gunk is removed and the scalp will quit overproducing oil as it normalizes. It can take persistence and forbearance to get off detergent shampoo and conditioner. But the persistence is worth it. Imagine soft natural shiny hair that only needs to be washed once a week, more or less, depending upon your body chemistry and your lifestyle. It will get better! I use a light hair oil on wet or dry hair to calm the frizz (I have long dry wavy hair) and to soften and moisturize. I am feeling quite happy with my hair. May you feel the same way with yours!

6 years ago

When you use a Oil do you put in wet or dry hair if used in wet hair do you rinse it out?