A clay mask absorbs surface oil, which is why clay masks are usually aimed at oily skin. This guide compares two raw clays from our shop, multani mitti (a stronger absorber) and rhassoul (a gentler one), and shows which suits which kind of oily skin, what the evidence does and does not show, and how to use either safely.
New to these clays? Our complete Multani Mitti guide covers origin, mineral profile, and all uses.
One 2023 study of a clay mask in adults with oily or combination skin found skin-oiliness readings 29.90% lower at week 4, but it had no comparison group and was funded by L'Oréal.
Multani mitti is the stronger absorber and is sold for oily and combination skin. Rhassoul is a medium absorber that our product page describes as suiting sensitive skin. We found no trial comparing them.
Use a thin layer once or twice a week and rinse before it cracks. Stop if it itches, burns or stings. The AAD says a mask applied too often can leave skin feeling worse.
Clay is one of several ingredient types the AAD lists for oily or acne-prone skin masks, alongside AHAs, BHAs and niacinamide, so a clay mask is an option, not a requirement.
Does a Clay Mask Work on Oily Skin?
It absorbs surface oil, and the best evidence we read supports that, but the evidence is small and comes from one commercial product. In a 2023 study in Skin Research and Technology, 75 adults with oily or combination skin were given a kaolin-and-bentonite clay mask, made with other ingredients, to use twice a week for 4 weeks, and 60 completed it. Skin-oiliness readings fell 29.90% by week 4, and skin-hydration readings rose. The study had no comparison group and was funded by L'Oréal, whose La Roche-Posay brand makes the mask, and it tested a formulated product rather than a raw clay, so it says little about either of these clays.
The American Academy of Dermatology (AAD) lists clay, “like kaolin or bentonite, to help absorb oil and soothe irritation,” as one of several ingredient types for oily or acne-prone skin, alongside exfoliating acids (AHAs and BHAs), lightweight moisturizers and niacinamide. Clay minerals are also widely used in cosmetics as adsorbents or absorbents, according to a 2017 review in the International Journal of Pharmaceutics.
The takeaway: a clay mask is a plausible way to take oil off the surface, and one study of a formulated mask supports it, but the evidence is small, uncontrolled and not about raw clay. Treat it as an optional step in your routine.
Which Clay Is Better for Oily Skin: Multani Mitti or Rhassoul?
Multani mitti suits oily skin that tolerates a strong absorber. If your oily or combination skin gets tight, flaky or irritated after stronger masks, our product page points to rhassoul instead. That split comes from our own product pages, not from a trial: we found no study comparing the two.
- Multani mitti: sold as a strong absorber for oily and combination skin, mixed as about 1 teaspoon with water or rose water, and used once or twice a week. Our product page calls it the wrong clay for dry or sensitive skin.
- Rhassoul: a medium absorber that swells in water, sold for skin that congests but cannot tolerate a stronger mask, mixed as roughly equal parts clay and water and left on for 10 to 15 minutes without letting it dry to a hard crust.
- Combination skin: use multani mitti only on the oily areas, such as the T-zone, or choose rhassoul for the whole face.
For a side-by-side of the two clays, read our Rhassoul Clay vs Multani Mitti guide.
Strong absorber, no fillers
Multani Mitti Clay
100% pure Fuller's Earth — no talc, no fragrance, no fillers. The unblended clay sourced and sold at the Sampson Standard.
Shop now → ✓ 30-day money-back guarantee · Free shipping over $75
Medium absorber, single ingredient
Rhassoul Clay
Raw Moroccan rhassoul clay, sold by weight with nothing added. A medium absorber for skin that can't take the strong clays.
Shop now → ✓ 30-day money-back guarantee · Free shipping over $75How Do You Use a Clay Mask on Oily Skin?
Mix the clay with water or rose water to a smooth paste, spread a thin layer over clean skin, rinse before it dries to a hard crack, and moisturize lightly if your skin feels tight. Here is the method:
- Patch-test first: Test a small amount on a small area of skin first, as the AAD advises for any new facial mask, and check for redness or irritation.
- Mix your mask: For multani mitti, combine about 1 teaspoon with enough water or rose water to make a smooth paste. For rhassoul, mix roughly equal parts clay and water, about 1 tablespoon of each for a face mask. Use a non-metal bowl and spoon.
- Apply to clean skin: Wash your face first, then spread an even layer over clean skin, avoiding the eye area.
- Watch the timing: Leave multani mitti on until it is dry to the touch but still slightly tacky, and leave rhassoul on for 10 to 15 minutes. Do not let either dry to a hard crack. An AAD page quotes a dermatologist warning that leaving a facial mask on longer than intended can cause irritation.
- Rinse gently: Rinse with lukewarm water and pat dry. If you feel itching, burning or stinging, wash the mask off straight away, as the AAD advises.
- Moisturize if needed: Follow with a light moisturizer if your skin feels tight. The AAD lists lightweight moisturizing ingredients, such as aloe or hyaluronic acid, among the ingredients for oily or acne-prone skin.
How Often Should You Use a Clay Mask on Oily Skin?
Once or twice a week at most. Both of our product pages set that limit, and more is not better for oily skin. The AAD says a mask applied too often can leave your skin feeling worse.
Who Should Skip a Clay Mask?
Anyone with dry or sensitive skin should skip multani mitti, and anyone whose skin reacts to a mask should stop using it.
- Dry or sensitive skin: Skip multani mitti, which our product page calls the wrong clay for you. Rhassoul is the gentler option, and you should still patch-test it first.
- Anyone with an allergy or reaction: An AAD page quotes a dermatologist noting that an allergy to a mask ingredient can cause contact dermatitis, a type of eczema. Wash the mask off if you feel itching, burning or stinging.
- Masks with added fragrance or essential oils: The AAD page says dermatologists advise avoiding facial masks with fragrance, essential oils or rubbing alcohol. Our multani mitti and rhassoul are single-ingredient powders with none of those added.
When Should You See a Professional?
A clay mask is at most an optional extra, so consult a dermatologist or healthcare professional if:
- You have severe, cystic or painful breakouts
- Your skin is getting worse despite a consistent routine
- Your skin itches, burns or stings after a mask
Our Multani Mitti for Acne guide covers what the evidence does and does not show for breakouts.
This content is for informational purposes only and is not medical advice. Individual results may vary.
Frequently Asked Questions
Can I use a clay mask on oily skin every day?
No. Both of our product pages limit clay masks to once or twice a week, and the AAD says a mask applied too often can leave skin feeling worse.
Does a clay mask dry out oily skin?
It can. An AAD page quotes one dermatologist warning that a mask with the wrong ingredients for your skin can lead to irritation, dryness or even breakouts, and another that leaving a mask on too long or using it too often can cause irritation. Rinse before it cracks, and moisturize lightly if your skin feels tight.
Do clay masks shrink pores?
We can't say they do. In the one study we read, pore area did not change significantly after 4 weeks of twice-weekly use of a clay mask.
Can I mix clay with anything else?
Keep it simple: water or rose water, as our product pages suggest. The AAD page says dermatologists advise avoiding masks with fragrance or essential oils, so skip those add-ins.