Clays & Charcoal · Clay
Red and Pink Clay
Kaolinite (as pink clay is labelled), illite (one red clay studied) and iron oxides as colour (a mineral mixture, not a plant) · also called Red clay, pink clay (shop names)
Red and pink clay are colour names for powders sold as face masks and in soap or bath products. They are not one mineral: a pink clay listing names kaolin plus iron oxides, while one red clay studied was mostly illite. No study of either on people's skin was found, and evidence is lab work. Some red clays held nickel, chromium and quartz, so safety comes first.
General information, not medical advice. Last substantive update · Not medically reviewed. A named clinician has not signed off on this page. How this page is made
About Red and Pink Clay
Red and pink clay are colour names, not one mineral. A pink clay listing names kaolin plus iron oxides, and one red clay studied was mostly illite with quartz. Research is lab work on a few samples. No trial supports masks, detox or swallowing, and some red clays held nickel, chromium and quartz.
What it is
"Red clay" and "pink clay" are shop names for clays coloured by iron minerals. One seller lists pink clay as kaolin plus iron oxides, a pale pink powder that turns deeper pink when wet.
Red clay can be something else. A red clay bought at a Durban market was mostly illite (56.7 percent) with quartz (31.3 percent). A product named Red Clay was mostly montmorillonite with quartz, calcite and dolomite. A red clay from Tenerife was a kaolinite type with hematite, magnetite and illite. So colour tells you little about the mineral.
Traditional and current uses
Clays have been used on the skin for a very long time. The Durban paper says red clay is sold there for use as a sunscreen and other cultural uses, and describes a custom in which a bride was covered in red clay for seven days.
Today red and pink clays are sold as face-mask powders and soap or bath ingredients. Traditional use is not proof that it works or is safe.
What the research shows
Lab work on a Durban red clay gave a sun protection factor of 18.6 in a light test, but it was never tried on skin, and the same clay showed no germ-killing effect. A six-clay study found only a green clay killed bacteria.
In dishes, a red hematite-rich clay and a kaolinite did not harm skin-type cells, while a montmorillonite product did.
The only human study read was a patch test of 53 adults using a different clay at 1 percent in a gel. It found no irritation or allergy, but it does not cover red or pink clays.
At a glance
Traditional uses history, not proof
- Clays have been used on skin for care and healing since ancient times (Nkosi 2024; Gomes 2018).
- A Durban market sells red clay for use as a sunscreen and other cultural uses (Nkosi 2024).
- A Pondo custom in South Africa smeared a bride with red clay for seven days, described as cleansing and lightening her skin (Nkosi 2024).
- Clay eating (geophagy) has been seen in all parts of the world since antiquity (Gomes 2018).
Studied for research
- Face masks for sensitive skin, insufficient evidence (seller claim)
- Sun protection, very low (lab reading only)
- Killing germs, very low (red clays did not in the lab)
- Detox or drawing out toxins, insufficient
- Swallowing for digestion, insufficient (risks reported)
- Skin tolerance, low (patch test of a different clay)
Main compounds
- Kaolinite (clay mineral)
- Illite (clay mineral)
- Iron oxides such as hematite and magnetite (colour)
- Quartz (a dust concern in some samples)
- Contaminant metals in some samples: nickel, chromium, lead, mercury
Common forms
- Dry powder
- Mask paste mixed with water
- Ingredient in soap and bath products
- Swallowed in water (not supported by the sources read)
Research links: Durban red and white clays, 2024 (full text) · Six clays tested on bacteria and skin cells, 2021 · Mercury in cosmetic clays, 2025 (abstract) · NCCIH: Detoxes and cleanses · Poison Control · Research Library · Genes & Biomarkers Library
What it is and its history
- Accepted scientific name
- Red and pink clay (colour names for several different clay products, not one mineral)
- Synonyms
- Red clay; Pink clay
- Common names
- Red clay (English); Pink clay (English)
- Family or group
- Clay mineral mixtures: kaolinite (pink clay as sellers label it), illite (one red clay studied), with iron oxides as the colour
- Native range
- Many sources. The pink clay listing says Australia; the red clay studied came from KwaZulu-Natal, South Africa (sold in Durban); another red clay came from Tenerife.
- Habitat
- Dug from sediment deposits.
- Harvest and processing
- Dug, dried and ground to powder; the Durban clays were sold in hardened balls and ground and sieved for the lab. Processing differs by supplier; not checked beyond that.
- Look-alikes and adulterants
- Name: Other clays with the same colour; Note: Colour is not a mineral name: red or pink products may be kaolin with iron oxides, illite with quartz, montmorillonite with carbonates, or a hematite-rich kaolin clay (2021, 2024 studies).
Traditional use and history history, not clinical proof
| Tradition or era | Documented use | Source |
|---|---|---|
| Ancient to modern | Healing clays have been used for therapeutic, nutritional and skin care purposes since early humans (Gomes 2018). Clay eating has been seen in all parts of the world since antiquity. | p28150053 |
| South Africa (Durban market and Pondo custom) | The Durban red clay is sold at a market for use as a sunscreen and other cultural uses. The paper also describes a Pondo custom in which a bride was smeared head to toe with red clay and kept in seclusion for seven days, to cleanse and lighten her skin. | p38827024 |
Traditional use shows how it was used. It does not show that it works or is safe today.
What is inside, and how it may work
What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.
Main compounds
| Compound | Family | Where it is concentrated | Activity studied | Level of evidence |
|---|---|---|---|---|
| Kaolinite | clay mineral | 87% in a kaolinite reagent; 6.5% in a product named Red Clay; 37% (as halloysite) in a red Tenerife clay. | Mineral structure; no drug-like activity described. Named by one seller as the base of pink clay. 5 11 | Laboratory |
| Illite | clay mineral | 56.7% in the Durban red clay; 17% in the red Tenerife clay. | Mineral structure; no drug-like activity described. 6 5 | Laboratory |
| Iron oxides (hematite, magnetite) | iron minerals / colorant | Hematite 23% and magnetite 17% in the red Tenerife clay. In the Durban red clay the authors suggest hematite or goethite from the hue but did not measure them. | Give the red or pink colour; the lab paper links iron to higher sun-protection reading. 5 6 | Laboratory |
| Quartz | non-clay mineral | 31.3% in the Durban red clay; 25.5% in a product named Red Clay. | Not an active ingredient; a dust concern. 6 5 | Laboratory |
| Nickel, chromium, lead (contaminant metals) | metals | Nickel 340, chromium 130, lead 27 ppm in the Durban red clay. | Not active ingredients; contaminants. 6 | Product analysis |
Mechanisms, receptors and pathways
| Target or pathway | Gene or receptor | What was found | Level |
|---|---|---|---|
| Adsorption of oils and other substances | None | Clay particles can bind substances; they could also bind heavy metals and make them available through eating or skin absorption. 4 | Narrative review |
| UVB absorption (lab) | None | A red clay with more iron gave a higher lab sun protection reading than a white clay. 6 | Laboratory |
| pH-dependent germ-killing (not seen in red clays) | None | Only a green clay killed bacteria in the six-clay study, and the effect was lost when neutralised. 5 | Laboratory |
Absorption, metabolism and elimination
- Absorption
- Not studied for red or pink clay. A review says metals in clay could be taken up through eating or skin absorption (theory).
- Distribution
- Not studied.
- Elimination
- Not studied.
- Bioavailability
- Not studied.
Isolated compounds versus whole extracts
Whole clay, clay-soaked water (leachate) and neutralised clay behaved differently in cells and against bacteria in the 2021 study, so results for one form do not carry over to another.
Nutritional composition
Clay is not a food or nutrient. A review says very large amounts of eaten clay can block iron, zinc and potassium.
1 low certainty3 very low certainty4 not enough evidence
What was looked at
The 8 benefits and uses checked for Red and Pink Clay, each with how strong the evidence is. Tap one to open it.
- Face masks for sensitive, stressed or dull skinNot enough evidence
- Gentle on skin (patch-test result for a different clay)Low certainty
- Sun protection (lab light test only)Very low certainty
- Killing germs (lab only)Very low certainty
- Detox or drawing out toxins and heavy metalsNot enough evidence
- Swallowing clay for digestion or cleansingNot enough evidence
- Rich in iron: absorbed through the skinNot enough evidence
- Effects on skin-type cells in a dishVery low certainty
Lab markers tracked in the studies
Sun protection factor (lab reading)Skin irritation and sensitisation on patch testMetals in the clay (parts per million)
What is Red and Pink Clay good for?
The uses people ask about and how strong the evidence is for each. None is proven for red or pink clay, and the lab results do not show benefit in people.
Benefits, one by one
Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.
Face masks for sensitive, stressed or dull skin
Not enough evidenceSellers say pink clay balances and soothes sensitive skin. No study of a red or pink clay mask on people's skin was found.
2 studiesNot advised.
Studies, doses and limits
Results
One seller lists a pink clay as kaolin plus iron oxides and recommends it for sensitive skin. That is marketing, not research.
Why this rating
No human study of a red or pink clay on skin was found. The only source is a seller's claim.
Form and dose studied
Not advised.
Limits
Seller claims are not evidence.
Why researchers looked
Red and pink clays are sold as face masks and soap or bath ingredients. Sellers describe them as gentle clays.
Traditional use
A 2024 lab paper says clays have been used since ancient times to care for the skin, and that red clay is smeared on a bride in a traditional South African custom, described to cleanse and lighten her skin.
Proposed mechanism Pharmacological theory
Clays soak up oil and water because of their fine particles and large surface area. That is a property of the powder, not shown to help sensitive skin.
A proposed mechanism does not show that the effect happens in people.
Some red clays held nickel, chromium and quartz, and clays vary by product (see the Safety tab). Patch-test first and stop if skin reacts.
Gentle on skin (patch-test result for a different clay)
Low certaintyA gel with 1 percent of kaolinite-and-illite clay caused no irritation or allergy in a patch test on 53 adults. It was not a red or pink clay, so this does not cover them.
1 studiesClays at 1 percent in a gel in the study; not advice.
Studies, doses and limits
What the trials found
One patch test in 53 healthy adults (aged 18 to 70, skin types I to IV) with clay gels and emulsions. The clays came from sand-extraction residues in Brazil, mostly kaolinite and illite.
Results
No signs of skin irritation or sensitisation were found. Skin-type cells in a dish stayed above 75 percent survival at the highest amount tested.
Effect sizes as reported
No numbers beyond the survival figure.
Why this rating
A real human test, but one short study of different clays at 1 percent in a gel, in healthy adults. Not red or pink clay, and no metal or germ results in the part read.
Form and dose studied
Clays at 1 percent in a gel in the study; not advice.
Who was studied
Healthy adults, mostly lighter to medium skin types (I to IV).
Limits
Different clays; healthy skin; short test; Brazilian clays.
Why researchers looked
Makers must check that a clay ingredient does not irritate skin before putting it in creams and masks.
Traditional use
Not described in the sources read.
Proposed mechanism Clinical safety test
Not applicable. This is a safety check, not a treatment test.
A proposed mechanism does not show that the effect happens in people.
A clean patch test for one gel does not mean every red or pink clay is gentle. Test a small spot first.
Sun protection (lab light test only)
Very low certaintyIn a lab light test, one red clay from Durban scored a sun protection factor of 18.6 and a white clay 6.2. It was never tested on people. Do not use clay as sunscreen.
1 studiesNot applicable.
Studies, doses and limits
Results
Spectrophotometer reading of clay mixed in ethanol: sun protection factor 18.621 for the red clay and 6.231 for the white clay.
Why this rating
One sample of red clay, a lab reading and not a test on skin or in sunlight.
Limits
Two samples; no skin test; the paper itself says patch tests and SPF testing on volunteers are still needed.
Why researchers looked
In parts of South Africa red clay is sold at markets for use as a sunscreen and for other cultural uses.
Traditional use
Traditional use as a sunscreen at a Durban market (Nkosi and Thembane 2024).
Proposed mechanism Laboratory
The authors link the result to the red clay's iron content, which they say can reduce UVB passing through. They did not measure the iron minerals.
A proposed mechanism does not show that the effect happens in people.
A lab number is not protection from sunburn. Use proper sunscreen.
Killing germs (lab only)
Very low certaintyNeither the Durban red clay nor a product named Red Clay showed any germ-killing effect in the lab. In a six-clay study only a green clay did, and only when wet and acidic.
2 studiesNot applicable.
Studies, doses and limits
Results
The Durban red clay was resistant to all the tested germs in disc tests. In the 2021 study, only the green clay of six showed antibacterial effect, and that was lost when neutralised. A red clay from Tenerife and a product named Red Clay did not.
Why this rating
Lab only, few samples. The finding is that red clays did not work, not that they do.
Who was studied
Lab bacteria.
Limits
A few named samples; no human infection trial.
Why researchers looked
Some clays have been proposed as natural alternatives to antibiotics for skin infection.
Traditional use
Not described for red or pink clay.
Proposed mechanism Laboratory
The 2021 authors say acidity (pH) and the clay surface charge matter more than the mineral list.
A proposed mechanism does not show that the effect happens in people.
A clay mask is not a treatment for a skin infection. See a clinician.
Detox or drawing out toxins and heavy metals
Not enough evidenceNo study shows red or pink clay removes toxins from the body. A health agency says there is no compelling research that detox diets do this.
2 studiesNot applicable.
Studies, doses and limits
Results
NCCIH reports that a 2015 review found no compelling research that detox diets remove toxins. That statement is about detox diets in general, not clay.
Why this rating
No human data on red or pink clay for this claim.
Limits
Absence of evidence; the agency statement is general.
Why researchers looked
Sellers say clay pulls toxins out. Clay particles can hold some substances in a dish, and sellers carry the idea over to the body.
Traditional use
Eating or using clay for health is very old (Gomes 2018).
Proposed mechanism Pharmacological theory
Clay particles could adsorb toxins so they leave the body, but could also adsorb heavy metals and make them available through eating or skin absorption (2018 review abstract). No test in people was found.
A proposed mechanism does not show that the effect happens in people.
Some clays hold metals (see the Safety tab). Do not swallow clay for a detox.
Swallowing clay for digestion or cleansing
Not enough evidenceNo trial of swallowing red or pink clay was found. Reviews say large amounts of eaten clay can block iron, zinc and potassium, and that the safety of clay eating is not established.
3 studiesNone advised. The 200 g figure is a level at which harm was reported,…
Studies, doses and limits
What the trials found
Reviews of people who habitually eat clay soil; no trial of red or pink clay.
Results
The 2010 review says clay eaten at more than 200 grams a day, especially high-exchange clay, can impede iron, zinc and potassium absorption. The 2022 review says safety of clay eating is not fully established, toxicity has been poorly investigated, and some minerals found in eaten clays are toxic.
Why this rating
No trial. Reviews describe risks rather than benefits.
Who was studied
People who habitually eat clay.
Limits
The reviews cover soil eating, not cosmetic clay powders.
Why researchers looked
Clay eating (geophagy) is old and found in many places, and is thought to be common in pregnancy for nausea.
Traditional use
Clay eating has been seen in all parts of the world since antiquity (Gomes 2018).
Proposed mechanism Pharmacological theory
Clay with high cation-exchange capacity can hold on to minerals in the gut (2010 review).
A proposed mechanism does not show that the effect happens in people.
Do not swallow cosmetic clay. If someone has and feels unwell, call poison control (see the Safety tab).
Rich in iron: absorbed through the skin
Not enough evidenceRed clay is coloured by iron minerals, but no source shows iron from a mask enters the body or helps anyone.
3 studiesNot applicable.
Studies, doses and limits
Results
Colour does not name the mineral: a product called Red Clay in the 2021 study was mostly montmorillonite, quartz and carbonates with little kaolinite, while the Durban red clay was mostly illite. A seller lists pink clay as kaolin plus iron oxides.
Why this rating
No study of iron uptake from a clay mask. Mineral facts come from a few samples.
Who was studied
Clay samples.
Limits
Samples are single products. The paper's text gives conflicting colour codes for its red clay.
Why researchers looked
Sellers link a clay's red or pink colour to its iron and say it feeds the skin.
Traditional use
Not described in the sources read.
Proposed mechanism Laboratory
Red colour in clay comes from iron oxide minerals. A Tenerife red clay was 23% hematite and 17% magnetite, and the authors credit its red colour to iron oxide. A Durban red clay was mostly illite and quartz with the highest iron of two samples, and the authors say hematite or goethite was suggested by its hue but not measured.
A proposed mechanism does not show that the effect happens in people.
Iron-rich red clays can also carry nickel, chromium and quartz (see the Safety tab).
Effects on skin-type cells in a dish
Very low certaintyA red hematite-rich clay and a kaolinite did not harm skin-type cells in a dish, and helped them close a scratch for the first day. A montmorillonite product harmed them over time. Cells are not skin.
1 studiesNot applicable.
Studies, doses and limits
Results
Suspensions of kaolinite and of a red Tenerife clay (kaolinite-halloysite, hematite, magnetite, illite) had no significant effect on skin-type cell survival, and suspensions of both helped scratch closure over 24 hours (leachate effects were not kept up to 48 hours). A montmorillonite product was toxic to the cells at 120 and 168 hours. All clay leachates were toxic to immune-type cells.
Why this rating
Cells in a dish, few products, effects not sustained.
Who was studied
Human skin-type (HaCaT) and immune-type (THP-1) cell lines.
Limits
Cell work only; one red clay of a kind not sold as a face mask.
Why researchers looked
To check whether clays help or harm human cells.
Traditional use
Not described in the sources read.
Proposed mechanism Laboratory
Unclear; the authors point to pH and clay surface charge.
A proposed mechanism does not show that the effect happens in people.
Mixed cell signals are a reason for caution, not reassurance.
Connections to the rest of health
How Red and Pink Clay connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.
Explore every connection: goals, body systems, organs, symptoms, genes
A. Wellness goals
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Healthy Skin | Not enough evidence | Face masks for sensitive, stressed or dull skin: Sellers say pink clay balances and soothes sensitive skin. No study of a red or pink clay mask on people's skin was found. | 11 6 | |
| Healthy Skin | Low certainty | Gentle on skin (patch-test result for a different clay): A gel with 1 percent of kaolinite-and-illite clay caused no irritation or allergy in a patch test on 53 adults. It was not a red or pink clay, so this does not cover them. | 8 | |
| Healthy Skin | Very low certainty | Sun protection (lab light test only): In a lab light test, one red clay from Durban scored a sun protection factor of 18.6 and a white clay 6.2. It was never tested on people. Do not use clay as sunscreen. Killing germs (lab only): Neither the Durban red clay nor a product named Red Clay showed any germ-killing effect in the lab. In a six-clay study only a green clay did, and only when wet and acidic. | 6 5 | |
| Detoxification Support | Not enough evidence | Detox or drawing out toxins and heavy metals: No study shows red or pink clay removes toxins from the body. A health agency says there is no compelling research that detox diets do this. | 9 4 | |
| Digestive Support | Not enough evidence | Swallowing clay for digestion or cleansing: No trial of swallowing red or pink clay was found. Reviews say large amounts of eaten clay can block iron, zinc and potassium, and that the safety of clay eating is not established. | 7 1 4 |
B. Body systems
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Integumentary System | Biological association | Not enough evidence | Studied for: Face masks for sensitive, stressed or dull skin Studied for: Gentle on skin (patch-test result for a different clay) | 11 6 8 5 |
| Immune System | Biological association | Very low certainty | Studied for: Killing germs (lab only) | 6 5 |
| Digestive System | Biological association | Not enough evidence | Studied for: Detox or drawing out toxins and heavy metals Studied for: Swallowing clay for digestion or cleansing | 9 4 7 1 |
I. Biomarkers
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Sun protection factor (lab reading) | Biological association | Very low certainty | Measured in trials: higher means more UVB blocked in the test. A lab change is not the same as a health benefit. | 6 |
| Skin irritation and sensitisation on patch test | Biological association | Low certainty | Measured in trials: no reaction seen. A lab change is not the same as a health benefit. | 8 |
| Metals in the clay (parts per million) | Biological association | Very low certainty | Measured in trials: reported as measured. A lab change is not the same as a health benefit. | 6 3 |
L. Active compounds
| Connected to | Kind of connection | Evidence status | Context | Studies |
|---|---|---|---|---|
| Kaolinite | Biological association | Laboratory | Mineral structure; no drug-like activity described. Named by one seller as the base of pink clay. | 5 11 |
| Illite | Biological association | Laboratory | Mineral structure; no drug-like activity described. | 6 5 |
| Iron oxides (hematite, magnetite) | Biological association | Laboratory | Give the red or pink colour; the lab paper links iron to higher sun-protection reading. | 5 6 |
| Quartz | Biological association | Laboratory | Not an active ingredient; a dust concern. | 6 5 |
| Nickel, chromium, lead (contaminant metals) | Biological association | Product analysis | Not active ingredients; contaminants. | 6 |
Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 25, 2026).
Evidence at a glance: what the research found for 8 outcomes
Each outcome below is one thing researchers measured. Certainty is how far the evidence can be trusted, not how well it works. The full studies are on the next tab.
The evidence
The research centre for Red and Pink Clay. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.
Evidence by outcome
Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).
How we rate evidence
High certainty
Several well-run trials or reviews agree; further research is unlikely to change the picture much.
Moderate certainty
Good trials point the same way, but some doubt remains.
Low certainty
Small, short or inconsistent trials. The finding could change with better research.
Very low certainty
Very little or very weak human data. Treat as a possibility only.
Mixed findings
Trials or reviews disagree with each other.
Not enough evidence
Not enough human research to say either way.
Evidence against
Good research found no benefit, or found harm.
We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We searched PubMed, read the abstract of each cited paper, read the Durban red and white clay paper and the six-clay paper in full text, read part of the Brazilian patch test paper, and read the FDA cosmetics, eCFR iron oxide, NCCIH detox and Poison Control pages. Certainty ratings are the compiler's own reading. One seller listing is cited only to show how a pink clay is labelled. Regulators outside the US were not checked. No study is cited that we could not verify.
Study library: every study we checked 13
| Study | Design | People | Product, dose, length | Result |
|---|---|---|---|---|
| Bonglaisin 2022 Geophagia: Benefits and potential toxicity to human-A review Frontiers in Public Health · PMID 35958861 · DOI |
Narrative review review |
Review of people who eat clay soil such as chalk or kaolin | Eaten clay soils (geophagy) mineral clay (not a plant) |
Says geophagy is global, thought to be common in pregnant women, and that its safety is not yet fully established. Reports that studies of its toxicity are inadequate, that some minerals found in eaten clays are toxic, and that the mix of minerals varies by region. Methods, limits and fundingOutcomes: Benefits and toxicity of eating clay Limitations: Review of eating clay soil, not cosmetic masks; toxicity was mostly judged from the presence of toxic elements, with few metabolic studies. Funding and conflicts: No conflicts declared. Read: abstract |
| Burnett 2026 Amended Safety Assessment of Naturally-Sourced Clays as Used in Cosmetics International Journal of Toxicology · PMID 42313106 · DOI |
Authoritative review review |
Eight naturally sourced clay ingredients used in cosmetics, reviewed by the Cosmetic Ingredient Review Expert Panel | Naturally sourced clay ingredients as used in cosmetics mineral clay (not a plant) |
The Panel concluded that kaolin is safe in cosmetics in present practices of use and concentration. The other seven clay ingredients are safe in present practices of use and concentration, except that available data are insufficient to decide if they are safe in products that may be incidentally inhaled. Methods, limits and fundingOutcomes: Safety in cosmetics as currently used Limitations: The abstract does not name which clays are the other seven. It is about cosmetic use, not swallowing. Funding and conflicts: The authors declared no conflicts of interest. Read: abstract |
| Fischer 2025 Analysis of Mercury Concentration in Cosmetic Clays Toxics · PMID 40559980 · DOI |
Product analysis product |
Cosmetic clays of different colours from different makers on the Polish market | Cosmetic clays, measured for mercury mineral clay (not a plant) |
Mercury was found in every sample. Mean 28.91 micrograms per kilogram, range 1.87 to 200.81. Highest averages were in green (53.26) and white (52.80) clays and lowest in purple (2.56) and blue (3.69) clays. The abstract does not give a figure for red or pink clays. The authors say these products likely need metal testing. Methods, limits and fundingOutcomes: Mercury concentration Limitations: One country, one metal; the abstract gives no red or pink figures. Funding and conflicts: No conflicts declared. Read: abstract |
| Gomes 2018 Healing and edible clays: a review of basic concepts, benefits and risks Environmental Geochemistry and Health · PMID 28150053 · DOI |
Narrative review review |
Review of healing clays used on skin and eaten clays | Healing and edible clays (general) mineral clay (not a plant) |
Says healing clays have been used for therapeutic, nutritional and skin care purposes, and could bring health and skin risks. Clay particles could adsorb toxins so they leave the body, but could also adsorb toxic elements such as heavy metals and make them available through eating or skin absorption. Geophagy has been seen in all parts of the world since antiquity. Methods, limits and fundingOutcomes: Benefits and risks of healing clays Limitations: A general review; the abstract names no red or pink clay. Funding and conflicts: Not stated in the abstract. Read: abstract |
| Incledion 2021 A New Look at the Purported Health Benefits of Commercial and Natural Clays Biomolecules · PMID 33466399 · DOI |
Lab study lab |
6 Six clays (five sold as medicinal or cosmetic clays and one natural red clay from Tenerife) tested on wound bacteria and on human immune-type (THP-1) and skin-type (HaCaT) cell lines |
Six clays as suspensions and filtered leachates, including a product named "Red Clay", a kaolinite, a green clay and a red hematite-rich clay mineral clay (not a plant) |
Abstract: all clay leachates were toxic to THP-1 immune-type cells while suspensions were less so; toxicity to HaCaT skin-type cells was lower and many leachates stimulated wound-healing responses; only the "Green" clay killed bacteria, and only as a suspension (lost on neutralising). Full text: the product named "Red Clay" was 32% montmorillonite, 25.5% quartz, 20% calcite, 16% dolomite and 6.5% kaolinite. The red Tenerife clay was 37% kaolinite (halloysite), 23% hematite, 17% magnetite and 17% illite; its red colour is attributed to high iron oxide. A kaolinite sample was 87% kaolinite. None of the clays except the green one showed antibacterial effect, whatever the minerals. Kaolinite and Tenerife clay suspensions did not harm skin-type cells and both helped scratch-wound closure at 24 hours; a montmorillonite product was toxic to them over time. Methods, limits and fundingOutcomes: Mineral make-up, antibacterial effect, cell toxicity and scratch-wound closure in cells Limitations: Cell and bacteria work; single products named by trade name; effects at 24 hours were not kept up to 48 hours. Funding and conflicts: No conflict of interest declared. Read: full-text |
| Nkosi 2024 Physical, chemical and biological characteristics of clays from Durban (South Africa) for applications in cosmetics Analytical Science Advances · PMID 38827024 · DOI |
Lab study lab |
2 One red and one white clay bought from informal traders at a market in Durban, South Africa, where they are sold for sunscreen and other cultural uses |
Red clay (one sample) and white clay (one sample), ground and tested in the lab mineral clay (not a plant) |
Full text: the red clay was mostly illite (56.7%) with quartz (31.3%), albite (9.9%) and vermiculite (2.0%). Its hue suggested iron minerals such as hematite or goethite, but they were not measured. Sun protection factor was 18.6 for red clay and 6.2 for white clay in a lab light test, not on skin. Metals by X-ray fluorescence in the red clay: lead 27 ppm, chromium 130 ppm, nickel 340 ppm; arsenic, mercury, cadmium and selenium were not detected. The authors say chromium was above the 5 ppm that another author suggested for products (they note no international limit exists). They also say quartz above 15% is a concern. Neither clay showed any antimicrobial activity in disc tests against the germs used. pH of the red clay was 4.79. The abstract lists the methods but gives no results. Methods, limits and fundingOutcomes: Mineral make-up, metals, pH, oil absorption, sun protection factor (spectrophotometer) and antimicrobial activity Limitations: Two samples only, from one market; lab work, not people; SPF measured in ethanol extract, not on skin; the text gives two different colour codes for the red clay. Funding and conflicts: No conflict of interest declared. Read: full-text |
| Williams 2010 Evaluation of the medicinal use of clay minerals as antibacterial agents International Geology Review · PMID 20640226 · DOI |
Narrative review review |
Review of clay use for skin infection, with lab tests of French green clays and other healing clays | Healing clays (general) mineral clay (not a plant) |
Abstract: natural clays have been used for skin infections since early recorded history, and "healing clays" are different from the few clays found to be antibacterial. Full text (read on PubMed Central): clay eaten at more than 200 grams a day, especially with high cation-exchange capacity, can impede absorption of iron, zinc and potassium; the US FDA does not require pre-market approval of cosmetics. Methods, limits and fundingOutcomes: Which clays kill bacteria; clay risks Limitations: Mostly about green clays; used here only for general clay points. Funding and conflicts: Not stated in the abstract. Read: full-text |
| da Silva Favero 2025 Physicochemical Characterization and Safety Assessment of Cosmetic Gels and Emulsions Containing Sand-Extraction Clays Journal of Cosmetic Dermatology · PMID 41128013 · DOI |
Lab study and patch test |
53 Four clays from sand-extraction residues (kaolinite and illite were the main minerals), tested on HaCaT skin-type cells and in a skin patch test on 53 healthy adults aged 18 to 70, skin types I to IV |
Clays at 1% in a gel and in an emulsion (clays were not red or pink clays sold as cosmetics) mineral clay (not a plant) 1% w/w in the gel (full text) Patch test (duration not read) |
Cells kept above 75% survival at the highest amount (1000 micrograms per millilitre). The patch test showed no signs of skin irritation or sensitisation. The text does not report metals or germ counts in the part read. Methods, limits and fundingOutcomes: Cell survival, skin irritation and sensitisation on patch testing, physical stability Limitations: Healthy volunteers, short patch test, clays from sand extraction rather than clay sold as red or pink; no comparison with other clays described in the abstract. Funding and conflicts: Funded by Brazilian universities and a state research foundation (acknowledgments). No conflicts declared. Read: abstract and part of the full text |
| n/a 2025 NCCIH (NIH): Detoxes and Cleanses: What You Need To Know (last updated March 2025) n/a · Source |
Authoritative guidance n/a |
n/a | n/a |
Says a 2015 review concluded there was no compelling research to support "detox" diets for weight management or for eliminating toxins from the body. The page is about detox diets and cleanses in general and does not mention clay in the passage read. Methods, limits and fundingOutcomes: Whether "detox" products and diets remove toxins Limitations: A health agency fact sheet about detoxes in general, not a clay study. Read: full-text |
| n/a 2025 FDA: FDA Authority Over Cosmetics: How Cosmetics Are Not FDA-Approved, but Are FDA-Regulated (content current as of 11/18/2025) n/a · Source |
Authoritative guidance n/a |
n/a | n/a |
Says cosmetic products and ingredients do not need FDA premarket approval, except colour additives, but FDA can take enforcement action against products on the market that do not comply with the law. Methods, limits and fundingOutcomes: How the US regulates cosmetics Limitations: Explains cosmetics law in general; it does not mention clay. Read: full-text |
| n/a 2026 Go Native NZ: Pink clay - Australia (seller listing, read 2026-10-25; a claim, not evidence) n/a · Source |
Seller listing n/a |
n/a | n/a |
The listing gives the ingredients (INCI) as kaolin and iron oxides, the origin as Australia, the look as a pale pink powder, and recommends it for sensitive skin. It says the clay can help hydrate, firm and brighten skin. These are the seller's claims. Methods, limits and fundingOutcomes: What one seller says a pink clay is Limitations: Marketing text from one seller. Used only to show how labels describe pink clay. No endorsement. Read: full-text |
| n/a 2026 Poison Control (National Capital Poison Center): home page, read 2026-10-25 n/a · Source |
Authoritative guidance n/a |
n/a | n/a |
Says help is free and confidential online and by phone at 1-800-222-1222 (US), and to call 911 if the person collapses, has a seizure, has trouble breathing or cannot be woken. Methods, limits and fundingOutcomes: What to do after a poisoning Limitations: Service information, not research. Read: full-text |
| n/a 2026 US Code of Federal Regulations, Title 21, section 73.2250: Iron oxides (eCFR text read 2026-10-25) n/a · Source |
Authoritative guidance n/a |
n/a | n/a |
Says the colour additives called iron oxides are synthetically prepared iron oxides, including hydrated forms. They must contain no more than 3 parts per million arsenic, 10 lead and 3 mercury. They are safe for colouring cosmetics generally, including around the eye, in amounts consistent with good manufacturing practice. The rule covers the factory-made colour, not a natural clay. Methods, limits and fundingOutcomes: Rules for iron oxide colour additives in cosmetics Limitations: Describes the factory-made colour additive, not clay itself. Read: full-text |
What we do not know yet
- No human study of a red or pink clay mask on any skin condition.
- No sun-protection test of any clay on skin.
- No human data on swallowing red or pink clay, in pregnancy, in children or with medicines.
- No testing of today's red and pink clay products for metals and quartz.
How new research is added
New studies are found by a saved PubMed search and are placed in a review queue. A person reads each one before it changes any evidence rating or safety wording.
Lab markers
What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".
Other 3
Sun protection factor (lab reading)
Higher means more UVB blocked in the test in trials
A number from a light-absorbing test that estimates how much UVB a material blocks. Here it was read from clay mixed in ethanol, not measured on skin.
Very low certaintyResults and what it means
Why it was measured
To see whether the clay could be a natural UV filter.
Statistical vs. clinical meaning
A lab number only, never tested on skin.
Safety implication
Do not rely on clay as sunscreen.
| Study | Result | People | Product |
|---|---|---|---|
| 6 | Red clay 18.621 and white clay 6.231 (full-text table). | Two clay samples | Spectrophotometer, 3 repeats |
Skin irritation and sensitisation on patch test
No reaction seen in trials
A patch with the product is kept on the skin and the skin is checked for redness and swelling.
Low certaintyResults and what it means
Why it was measured
To check that a clay ingredient does not irritate or cause allergy.
Statistical vs. clinical meaning
A different clay, healthy skin, short test.
Safety implication
Does not cover red or pink clay products.
| Study | Result | People | Product |
|---|---|---|---|
| 8 | No signs of irritation or sensitisation in 53 healthy adults. | 53 healthy adults, skin types I to IV | 1% kaolinite-illite type clay in a gel or emulsion |
Metals in the clay (parts per million)
Reported as measured in trials
The amount of metals found by lab analysis in a clay sample.
Very low certaintyResults and what it means
Why it was measured
Clay is dug from the ground and can carry metals that matter for skin and for swallowing.
Statistical vs. clinical meaning
Single samples; not a rule for all red clays.
Safety implication
See the Safety tab.
| Study | Result | People | Product |
|---|---|---|---|
| 6 | Red clay: lead 27, chromium 130, nickel 340 ppm; arsenic, mercury and cadmium not detected (X-ray fluorescence). | One red clay sample | Lab analysis |
| 3 | Mercury found in every cosmetic clay tested (1.87 to 200.81 micrograms per kilogram); no red or pink figure in the abstract. | Cosmetic clays, Poland | Atomic absorption analysis |
Safety
What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.
Main points to know 5
- Do not swallow it for a "detox". No study shows red or pink clay detoxes the body. Reviews say large amounts of eaten clay can block iron, zinc and potassium, and that the safety of eating clay is not established. Some minerals found in eaten clays are toxic. Narrative review 7 1 4 9
- Metals differ from one red clay to the next. One red clay from Durban held lead 27 ppm, chromium 130 ppm and nickel 340 ppm (no arsenic, mercury or cadmium detected). The authors say the chromium was above a 5 ppm level another author suggested for products, and that no international limit exists. Mercury was in every cosmetic clay tested in Poland. Laboratory analysis 6 3
- Avoid breathing the dry powder. The 2026 expert panel judged natural cosmetic clays safe as used, but said data are insufficient to decide for products that may be incidentally inhaled. The Durban red clay was 31.3 percent quartz, and its authors say quartz above 15 percent is a concern. Authoritative review 2 6
- Colour does not tell you what is in the jar. A product named Red Clay was mostly montmorillonite, quartz and carbonates. A Durban red clay was mostly illite. A pink clay listing names kaolin plus iron oxides. Ask for a lab report for metals. Laboratory analysis 5 6 11
- Cosmetic clay is not pre-approved. The FDA says cosmetic products and ingredients do not need premarket approval, except colour additives. A label cannot tell you the metals content. Authoritative guidance 10
Side effects 5
| Effect | How often | Severity and recovery | Evidence |
|---|---|---|---|
| Skin contact allergy to chromium or nickel (possible) The Durban authors say chromium can act as a trigger for contact allergy. No reaction to a red or pink clay in people was found. | Not established | unknown Not stated | Laboratory analysis 6 |
| Lower iron, zinc and potassium with very large clay eating Describes clay eating, not a mask. | Reported at over 200 g a day in older reports cited by a review | unknown Not stated | Narrative review 7 |
| Toxicity to skin-type cells for one montmorillonite product, and to immune-type cells for all leachates (dish) Cell work on commercial clays, not specifically red or pink. | Not established | unknown Not applicable | Laboratory 5 |
| No irritation or sensitisation seen in a 53-person patch test of a different clay at 1% Not a red or pink clay. | 0 of 53 reported in the abstract | none reported n/a | Human study 8 |
| No human adverse-event reports for red or pink clay masks were found Not described is not proof of safety. | Not established | unknown n/a | Gap |
Liver
No report of liver injury from red or pink clay was found. LiverTox was not searched.
How often. No rate in people.
Monitoring. No monitoring advice was found.
This is a safety connection. It is not evidence that Red and Pink Clay supports liver health.
Medicines and supplements 3
| With | Why it matters | Importance | Evidence | What to do |
|---|---|---|---|---|
| Medicines taken by mouth (in general) prescription | Clays can bind other substances, which could in theory reduce how much of a medicine is absorbed if clay is swallowed. | No interaction study with red or pink clay was found. The Gomes 2018 review says clay particles can adsorb substances, which is a theory here, not a measured drug interaction. | Pharmacological theory Not enough evidence 4 | If you take any medicine, do not swallow clay without asking a pharmacist. |
| Iron, zinc and potassium from food and supplements nutrient | Clay with high cation-exchange capacity may hold minerals in the gut. | A review says more than 200 g a day can impede absorption and lead to deficiencies. That is a very large amount and not a use recommendation. | Narrative review Low certainty 7 | Avoid swallowing clay if you are low in iron, are pregnant or have anaemia; ask a clinician. |
| Skin medicines or acne treatments topical | Not described in the sources read. | No study was found. | None found Not enough evidence | Ask a pharmacist or doctor before combining a clay mask with prescription skin products. |
Who should check first 6
| Situation | Advice | Evidence |
|---|---|---|
| Pregnancy and breastfeeding | Clay eating is thought to be common in pregnancy, but a review says its safety is not established. No data on red or pink clay were found. Do not swallow clay; ask a clinician before using it. | Narrative review 1 |
| Babies and children | No data were found. Keep powder out of reach and do not let children swallow or breathe it. | Gap |
| Open wounds, ulcers or skin infections | Do not self-treat with clay instead of care. The red clays tested did not kill germs in the lab. | Laboratory 6 5 |
| Anaemia, low iron or potassium, or kidney problems | Avoid swallowing clay. A review says very large intakes can lower iron, zinc and potassium. No kidney-specific data were found; ask a clinician. | Narrative review 7 |
| Asthma or other lung conditions | Avoid breathing dry powder. The expert panel says data are insufficient for products that may be inhaled. | Authoritative review 2 |
| Nickel or chromium allergy | One red clay held nickel and chromium. If you react to metals, be careful and ask a clinician. No report of a reaction to a clay mask was found. | Laboratory analysis 6 |
Overdose, product quality and regulators
Summary. Clay itself is not a plant, so there are no toxic plant parts. The concerns are metals and quartz in some samples, and large amounts if swallowed.
Animal. No animal study of red or pink clay was read.
Human doses studied. No dose studies of red or pink clay in people were found.
High dose or long term signals. A review reports older findings of low iron, zinc and potassium with clay eaten at over 200 g a day.
Overdose response. If someone has swallowed a clay product and feels unwell, call poison control (US 1-800-222-1222) or your local emergency number. Call 911 for collapse, seizure or trouble breathing.
Genotoxicity. Not read.
Clay is dug from the ground and can carry metals and quartz. Labels rarely say which, so the colour or name tells you nothing.
Lead, chromium and nickel in a red clay. A Durban red clay held lead 27, chromium 130 and nickel 340 ppm; arsenic, mercury and cadmium were not detected. A white clay from the same market held lead 16 and chromium 560 ppm. 6
Mercury. All Polish-market cosmetic clays tested held mercury (mean 28.91, range 1.87 to 200.81 micrograms per kilogram). The abstract names green and white as highest and purple and blue as lowest, with no figure for red or pink. 3
Quartz. The Durban red clay was 31.3 percent quartz; the authors cite a view that quartz above 15 percent is a concern. A kaolinite and a product named Red Clay also held quartz (10 and 25.5 percent). 6 5
Iron oxide colour added in a factory. US rules for synthetic iron oxide colour set limits of 3 ppm arsenic, 10 ppm lead and 3 ppm mercury. That rule is for the factory-made colour, not for natural clay. 13
| Body | Action | Date |
|---|---|---|
| Cosmetic Ingredient Review Expert Panel (US) (United States) | Kaolin is safe in cosmetics in present practices of use and concentration. The remaining seven clay ingredients are safe as used, except data are insufficient for products that may be incidentally inhaled. source | 2026-06-18 |
| US FDA (cosmetics) (United States) | Cosmetic products and ingredients (except colour additives) do not need premarket approval; FDA can take enforcement action against non-compliant products on the market. source | 2025-11-18 |
| US FDA (colour additives, 21 CFR 73.2250) (United States) | Synthetic iron oxides are safe for colouring cosmetics, including around the eye, in amounts consistent with good manufacturing practice; limits 3 ppm arsenic, 10 ppm lead, 3 ppm mercury. source | |
| NCCIH (US National Institutes of Health) (United States) | Says a 2015 review found no compelling research that detox diets remove toxins. source | 2025-03 |
When to get medical help
- Collapse, a seizure, trouble breathing or being impossible to wake after swallowing or breathing in clay or clay dust: call emergency services (911 in the US) now.
- Swallowed a clay product and feel unwell, or a child has swallowed it: call poison control (US 1-800-222-1222) or your local emergency number.
- Wheeze, cough or chest tightness after breathing in dry powder: stop and get medical advice.
- A skin rash, swelling or blistering after a clay mask: wash it off, stop using it and ask a pharmacist or doctor.
- A skin ulcer or wound with spreading redness, pus, fever or worsening pain: get medical care, do not use clay instead.
Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.
General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.
Frequently asked questions
What is the difference between red clay and pink clay?
What gives red and pink clay their colour?
Does red or pink clay detox the skin or body?
Is it safe to eat red or pink clay?
Does a pink or red clay mask help sensitive skin?
Does red clay protect from the sun?
Only in a lab light test. A Durban red clay scored 18.6 and a white clay 6.2, and neither was tried on skin. The paper itself says testing on volunteers is still needed. Use proper sunscreen.
Is red clay antibacterial?
Do red or pink clays contain heavy metals?
Is it safe in pregnancy, while breastfeeding or for children?
No data on red or pink clay were found. A review says clay eating is thought to be common in pregnancy but its safety is not established. Do not swallow it, keep powders away from children, and ask a clinician first.
Can it affect my medicines?
No interaction study was found. In theory clay can bind other substances if swallowed, so ask a pharmacist before taking clay if you use medicines.
Is breathing the dry powder a problem?
Is clay regulated like a medicine?
Not as a cosmetic. The FDA says cosmetic products and ingredients, except colour additives, do not need premarket approval, though it can act against non-compliant products. Other countries were not checked.
Explore by health goal
Editorial transparency
- Written by
- AlternativeMed editorial team. Research compiled with AI assistance, then checked against PubMed records.
- Medical review
- None. This page has not been reviewed by a physician or pharmacist.
- First published
- 2026-10-25
- Last substantive update
- 2026-10-25
- How we research
- We searched PubMed, read the abstract of each cited paper, read the Durban red and white clay paper and the six-clay paper in full text, read part of the Brazilian patch test paper, and read the FDA cosmetics, eCFR iron oxide, NCCIH detox and Poison Control pages. Certainty ratings are the compiler's own reading. One seller listing is cited only to show how a pink clay is labelled. Regulators outside the US were not checked. No study is cited that we could not verify.
- How we rate evidence
- See "How we rate evidence" in the Evidence tab.
- Independence
- No product is promoted on this page. No affiliate links are shown.
Sources 13
Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.
- Bonglaisin JN, Kunsoan NB, Bonny P, et al. Geophagia: Benefits and potential toxicity to human-A review. Frontiers in Public Health. 2022. PMID 35958861. DOI 10.3389/fpubh.2022.893831. (abstract)
- Burnett CL, Bergfeld WF, Belsito DV, et al. Amended Safety Assessment of Naturally-Sourced Clays as Used in Cosmetics. International Journal of Toxicology. 2026. PMID 42313106. DOI 10.1177/10915818261455355. (abstract)
- Fischer A, Brodziak-Dopierala B, Janska W, et al. Analysis of Mercury Concentration in Cosmetic Clays. Toxics. 2025. PMID 40559980. DOI 10.3390/toxics13060507. (abstract)
- Gomes CSF. Healing and edible clays: a review of basic concepts, benefits and risks. Environmental Geochemistry and Health. 2018. PMID 28150053. DOI 10.1007/s10653-016-9903-4. (abstract)
- Incledion A, Boseley M, Moses RL, et al. A New Look at the Purported Health Benefits of Commercial and Natural Clays. Biomolecules. 2021. PMID 33466399. DOI 10.3390/biom11010058. (full-text)
- Nkosi SM, Thembane N. Physical, chemical and biological characteristics of clays from Durban (South Africa) for applications in cosmetics. Analytical Science Advances. 2024. PMID 38827024. DOI 10.1002/ansa.202300062. (full-text)
- Williams LB, Haydel SE. Evaluation of the medicinal use of clay minerals as antibacterial agents. International Geology Review. 2010. PMID 20640226. DOI 10.1080/00206811003679737. (full-text)
- da Silva Favero J, Dos Santos V, Weiss-Angeli V, et al. Physicochemical Characterization and Safety Assessment of Cosmetic Gels and Emulsions Containing Sand-Extraction Clays. Journal of Cosmetic Dermatology. 2025. PMID 41128013. DOI 10.1111/jocd.70517. (abstract and part of the full text)
- n/a. NCCIH (NIH): Detoxes and Cleanses: What You Need To Know (last updated March 2025). n/a. 2025. (full-text)
- n/a. FDA: FDA Authority Over Cosmetics: How Cosmetics Are Not FDA-Approved, but Are FDA-Regulated (content current as of 11/18/2025). n/a. 2025. (full-text)
- n/a. Go Native NZ: Pink clay - Australia (seller listing, read 2026-10-25; a claim, not evidence). n/a. 2026. (full-text)
- n/a. Poison Control (National Capital Poison Center): home page, read 2026-10-25. n/a. 2026. (full-text)
- n/a. US Code of Federal Regulations, Title 21, section 73.2250: Iron oxides (eCFR text read 2026-10-25). n/a. 2026. (full-text)
