Rhassoul and bentonite are both clays that people mix into face masks and hair washes, but no trial has compared them. This guide sets out what we could source, and where the usual advice has no evidence behind it.
New to rhassoul? Our complete rhassoul clay guide covers what it is and how it is used, or go straight to our Rhassoul Clay.
No trial compares rhassoul with bentonite, so the choice rests on our product pages and the AAD rather than head-to-head data.
The AAD names kaolin and bentonite, not rhassoul, among clays that help absorb oil in masks for oily or acne-prone skin; our product page rates rhassoul a medium absorber.
Bentonite appears in trials of finished masks, but the two we read do not isolate the clay itself, and we found no study of rhassoul as a hair wash or skin mask.
Patch-test whichever you choose, follow any label timing, and rinse it off if it itches, burns or stings. The AAD warns that masks used too often or left on too long can cause irritation.
What Is Rhassoul Clay?
Rhassoul, also called ghassoul, is a Moroccan clay that a 2020 mineralogy study found to be essentially stevensite, a magnesium smectite, with calcite, dolomite and quartz. Our rhassoul clay guide covers it in full.
Our product page sells it as a medium absorber that swells in water, gentler than the strong absorbers, for skin that congests but cannot take a stronger mask. That is a positioning statement, not a trial result, because no trial has tested rhassoul on facial skin.
What Is Bentonite Clay?
Bentonite is a clay that the AAD names, along with kaolin, among mask ingredients that help absorb oil and soothe irritation for oily or acne-prone skin. That is an ingredient list, not proof that a bentonite mask clears acne.
Two studies tested finished products that contain it. In a 2023 single-arm study of a commercial kaolin-and-bentonite mask, skin-oiliness readings fell over 4 weeks of twice-weekly use and pore area did not change significantly; it had no comparison group and was funded by L'Oréal. In a 2025 randomized trial, 60 people with moderate acne all took azithromycin, and lesion counts and acne severity fell more with a bentonite and Alcea sulphurea mask than with a placebo gel, although the mask could not be blinded.
Neither study isolates bentonite, because each mask combined it with other ingredients. We do not quote figures for bentonite's swelling, acidity or mineral content, because we could not source them.
What Are the Key Differences?
The differences we can source are small: rhassoul is identified as stevensite, our product page rates it a medium absorber, and the AAD names bentonite rather than rhassoul for oil control. Anything beyond that in a comparison table is unsourced.
| What we can source | Rhassoul Clay | Bentonite Clay |
|---|---|---|
| What it is | Stevensite, a magnesium smectite from Morocco (2020 mineralogy study) | A clay the AAD names alongside kaolin in oil-absorbing masks |
| Absorbency | Medium (our product page) | Grouped with the strong absorbers on our rhassoul product page |
| Named by the AAD for oily or acne-prone masks | No | Yes |
| Skin studies we found | None on facial skin; three ostomy case studies (2018) | Two finished-mask studies (2023, 2025); neither isolates the clay |
| Hair studies we found | None | A 2026 lab study of bentonite in solid shampoo and conditioner |
Which Works Better for Face?
We can't say either works better, because no trial compares them. What we can say is where each sits: the AAD's list for oily and acne-prone masks names bentonite (with kaolin), and our product page positions rhassoul as the gentler, medium-absorbency option for skin that can't take a stronger mask.
If your skin is oily, the AAD's list points to kaolin or bentonite for absorbing oil, though a list of ingredients is not evidence for either. If your skin is dry, sensitive or reacts to masks, a lower-absorbency clay such as rhassoul is the more cautious choice, but patch-test either one first.
The AAD says a mask used too often can leave skin feeling worse, and that an allergy to a mask ingredient can cause contact dermatitis. For acne that is deep, painful or worsening, see a dermatologist rather than relying on a mask.
Which Works Better for Hair?
We can't say, because no study compares them and we found none of rhassoul as a hair wash. The nearest evidence is a 2026 lab study in the International Journal of Cosmetic Science, which added two commercial clays, one identified as bentonite, to solid shampoo and conditioner and found stronger hair fibres, improved combing force and more gloss; it tested formulated products on hair fibres, not a clay-paste wash, and not rhassoul.
Some people use either clay as a “clay wash” in place of shampoo, mixing a paste, working it through hair and scalp and rinsing thoroughly. Stop if your scalp itches or burns. Our Rhassoul Clay for Hair guide covers technique.
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Rhassoul Clay
Single-ingredient Moroccan rhassoul clay powder, sold by weight. A medium-absorbency clay you mix into a fresh mask each time.
Shop now → ✓ 30-day money-back guarantee · Free shipping over $75Which Should You Choose?
Choose by your skin's tolerance, not by a claimed winner. If your skin is oily and tolerates masks, bentonite is the clay the AAD names for oil control; if your skin is dry, sensitive or reactive, rhassoul is the milder clay on our product page.
- Rhassoul: our product page describes a medium-absorbency clay for skin that congests but can't tolerate a stronger mask. Start with one mask a week.
- Bentonite: the AAD names it for oily or acne-prone skin, but we could not source how strong or drying it is, so patch-test and follow the product's label.
- Neither: if your acne is deep, painful or worsening, or a mask irritates your skin, see a dermatologist.
Comparing rhassoul with another oil-absorbing clay? Our Rhassoul Clay vs Multani Mitti guide covers it.
Frequently Asked Questions
Can I mix rhassoul clay and bentonite clay together?
We found no source on blending them or on ratios, so we can't recommend a mix. Combining two clays multiplies the unknowns; if you try it, patch-test first and follow the label directions for each.
Is rhassoul clay or bentonite better for acne-prone skin?
Nobody has tested them against each other. The AAD names bentonite, not rhassoul, among clay ingredients for oily or acne-prone masks, and a 2025 trial found a bentonite-and-plant-extract mask helped alongside an antibiotic, but that does not isolate the clay. For deep, painful or worsening acne, see a dermatologist (AAD acne overview).
How often should I use a clay mask?
We found no source that gives an ideal number. Our product page describes a weekly mask for rhassoul, and the AAD says a mask used too often, or left on longer than intended, can cause irritation. Our clay-mask frequency guide covers what the sources say.
Is bentonite clay safe to use on skin?
We can't give a bentonite-specific answer, because the mask studies we read combined it with other ingredients. The 2025 randomized trial reported no serious side effects from its bentonite-and-plant-extract mask, and the AAD warns that an ingredient allergy can cause contact dermatitis. Patch-test first, avoid broken or irritated skin, and wash it off if it itches, burns or stings.
Does rhassoul clay actually condition hair, or is that marketing?
We could not find evidence that it does. Europe PMC searches on 2026-09-23 for rhassoul or ghassoul with hair or shampoo returned no hair trial. Some people describe soft hair after a clay wash, but that is anecdote, not evidence.
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