Marseille soap is a traditional French soap that many people keep as an all-purpose bar, and a few try as shampoo. We found no study of it on hair, so this guide sets out what is known about soap and hair in general, what our own product pages say, and how to try it cautiously if you choose to.
For the wider picture, see our guide to what Marseille soap is and our 10 everyday uses. Our Aleppo soap for hair guide asks the same question of a different soap.
We found no study of Marseille soap on hair, and our cube's product page lists laundry, stains, household cleaning and hand and body washing, not hair.
A 2014 review that also measured 123 shampoos says alkaline pH may raise friction between hair fibres and damage the cuticle, and describes soap as leaving an alkaline residue.
We could not find a measured pH for our Marseille cube, so we quote none. Our Authentic Marseille Soap bar is scented and palm-based, while the cube is fragrance-free olive oil soap.
If you try it anyway, patch-test first, rinse thoroughly, follow with conditioner, and stop if your scalp itches or your hair turns dry or tangled. See a doctor for a red or very itchy scalp.
Can You Use Marseille Soap on Your Hair?
You can, but no study has tested it and it is not sold for hair. The product page for our Traditional Olive Oil Marseille Soap Cube lists laundry detergent, stain remover, household cleaning, and hands and body; hair is not on the list. Europe PMC searches on 2026-09-23 for Marseille soap with hair, shampoo or scalp returned no study of it.
It is a soap, not a shampoo. The cube's ingredient list reads Sodium Olivate, Aqua, Glycerin, Sodium Chloride and Sodium Hydroxide, with no added fragrance, and the product page says the lye is fully spent when the olive oil is turned into soap.
Why Does Soap Act Differently From Shampoo on Hair?
Because hair-care research focuses on pH and fibre friction, and soap is alkaline. In a 2014 review in the International Journal of Trichology, the authors report a scalp pH of 5.5 and a hair-shaft pH of 3.67, and say alkaline pH may increase the negative electrical charge on the hair surface, raising friction between fibres and possibly causing cuticle damage and breakage.
The same review describes soap as leaving “an alkaline residue” that, in its source, can precipitate as calcium salts and leave hair opaque and tangled, which is a hard-water concern. It is a narrative review, not a trial of washing hair with soap.
It also measured the pH of 123 shampoos: they ranged from 3.5 to 9.0, and 61.78% sat above 5.5. So alkalinity is not unique to soap. We could not find a measured pH for our cube, so we quote none.
Which Marseille Soap Should You Use, If Any?
If you try one at all, the fragrance-free cube is the simpler choice. Our Authentic Marseille Soap bar is a palm-oil soap base with glycerin, and its ingredient list includes Parfum across more than thirty scents.
The AAD advises, in its guidance for children with eczema, choosing fragrance-free rather than unscented products, because unscented means a fragrance is masked while fragrance-free means none is added. Our Marseille soap for sensitive skin guide covers the skin side.
Featured in this guide
Traditional Olive Oil Marseille Soap Cube
Olive-oil Marseille soap cube with no added fragrance. Sold for laundry, stains, household cleaning, and hands and body.
Shop now → ✓ 30-day money-back guarantee · Free shipping over $75How Do You Try It Cautiously?
Patch-test, lather the soap in your hands, work it through wet hair, rinse thoroughly and follow with conditioner. These steps are common technique, not trial-tested.
- Patch-test first: The AAD suggests testing a product on a small spot of skin twice daily for seven to 10 days, and for a wash-off product, leaving it on for five minutes or as long as its instructions say.
- Lather in your hands: Wet the soap, build a lather between your palms and apply the lather rather than rubbing the block on your scalp.
- Wash a small area first: Try one wash and watch how your hair and scalp feel over the next few days before repeating.
- Rinse thoroughly: Rinse well, since the review links soap residue and calcium salts in hard water to dull, tangled hair.
- Condition afterward: The review lists lubricating agents among what shampoos are formulated with to reduce friction, and soap is not formulated that way, so a conditioner is a sensible step.
- Stop if it goes wrong: Stop if your scalp itches or burns, or your hair turns dry, rough or tangled.
Some guides suggest a diluted vinegar rinse afterward. We found no study of that on soap-washed hair, so we do not recommend it as a fix.
When Should You See a Doctor Instead?
See a GP or dermatologist if your scalp is red or swollen, very itchy, or flaky in patches, or if dandruff persists, and do not rely on a soap change. The NHS says to see a GP if you still have dandruff after at least 4 weeks of anti-dandruff shampoo, if it is bad or your scalp is very itchy, if your scalp is red or swollen, or if you have flaky, itchy patches on your face or body.
The AAD recommends seeing a board-certified dermatologist for an accurate diagnosis if you think you could have seborrheic dermatitis. For hair you are worried about, a soap swap is not a diagnosis.
This content is for information only and is not medical advice. Individual results may vary.
Frequently Asked Questions
Is Marseille soap good for hair growth?
We found no study linking Marseille soap to hair growth, so we make no such claim. If you are losing hair, see a dermatologist rather than changing soaps.
Can I use Marseille soap as shampoo every day?
We can't recommend daily use, because nobody has tested it. If you try it, start with a single wash and watch how your hair and scalp feel over the next few days before repeating.
Is Marseille soap better than shampoo for a sensitive scalp?
No study compares them. The AAD advises fragrance-free rather than unscented products in its guidance for children with eczema; our cube is sold with no added fragrance, while our Authentic Marseille Soap bar lists Parfum. For a red or very itchy scalp, see a doctor.
Will Marseille soap strip hair color?
We found no source on how soap washing affects hair colour. Test a small hidden section first and ask your stylist.
Is Marseille soap or Aleppo soap better for hair?
No study compares them for hair. Our Aleppo soap for hair guide asks the same question of a laurel-oil soap, and our Aleppo vs Marseille soap guide compares the two soaps generally.
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