I get asked this a lot. Sometimes by people who’ve just stumbled into the crunching world and are curious, sometimes by a worried partner or parent, and occasionally by someone who has clearly decided I’m the villain before they’ve finished typing.
Before anything else, let me say this plainly. I’m not here to judge anyone for eating clay. Not for pica, not for geophagy, not for reaching for a bit of chalk because it scratches an itch nothing else does. People have been doing this for thousands of years, plenty of cultures treat it as completely normal, and the shame that gets piled on this community does a lot more harm than it ever prevents.
We’re adults. What goes in your body is your call. Not mine, not your nosy aunt’s, and definitely not the comment section’s.
But a judgement call is only really yours if you’ve got the facts to make it with. So here’s my honest answer to the question, and some of you aren’t going to love it.
It can be.
Not always, not for everyone, and not in the dramatic way the comment sections would have you believe. But I sell clay, and I’d be a pretty rubbish advocate for this community if I pretended there were no risks. There are. So here’s what they actually are, with sources at the bottom so you don’t have to take my word for any of it.
People have been eating earth for a very long time
Geophagy isn’t new and it isn’t niche. Hippocrates wrote about it more than 2,000 years ago. In 2011 a team at Cornell led by Sera Young pulled together more than 480 cultural accounts of people eating earth and found it on pretty much every inhabited continent. It turns up most in early pregnancy and in young children, and it turns up even where food is plentiful, so the idea that people only do it because they’re starving doesn’t hold.
Their best explanation was protection: clay binding to toxins, parasites and germs, or coating the gut a bit like a face mask. I find that genuinely fascinating. But it came from looking at patterns across historical and anthropological records, not from feeding people clay and measuring what happened, and the researchers themselves said it needed more study. They also found that the popular “your body is craving minerals” explanation was a poor fit, partly because the minerals in soil aren’t very easy for the body to absorb.
So no, I’m not going to tell you clay is good for you. Nobody has proven that. What has been studied a lot more is what can go wrong.
The big one is what’s actually in it
Clay is whatever the ground it came from is. Its make-up changes from one region to the next, so two clays that look identical in the bag can be completely different underneath. Some contain heavy metals, and lead and arsenic are the ones that come up again and again in the research.
This isn’t hypothetical. The Food Standards Agency has been telling people not to eat calabash chalk (also sold as nzu, la craie, argile and mabele) since 2002, after testing found high levels of lead. Public Health England later put out its own alert after seized samples showed lead and sometimes arsenic. Ireland’s food safety authority issued the same warning again in May this year. The FSA has also named specific bentonite clay drinks after finding unsafe levels of arsenic and lead, and in the US the FDA told people to stop using two bentonite products, one of them sold as a beauty clay that also said you could eat it.
Yes, West African clays are in my shop. That’s exactly why I’m writing this paragraph instead of skipping past it.
And while I’m being straight with you, here’s the bit about my own shop. Most of what I sell is listed as Community-Tested. That means people in this community have crunched it and know the vendor. It does not mean a lab has checked it for lead. Where a vendor tells me something is lab-tested but I haven’t seen the certificate myself, the listing says that too. I’d rather you know than assume.
Lead is the one I’d take most seriously. It builds up in the body over time, it passes to babies during pregnancy, and it’s particularly hard on developing brains. There’s no “but it’s natural” exemption here. Lead is natural too.
Iron, and the chicken and egg problem
Clay cravings and low iron turn up together so often that doctors treat pica as a nudge to check someone’s iron. Nobody is completely sure which comes first. Low iron might drive the craving. But clay, kaolin in particular, can also get in the way of your gut absorbing iron, so the habit can make a deficiency worse. There’s a published case of a man who started eating kaolin after watching a documentary, became iron deficient over a few years, and recovered once he stopped.
So if the cravings are new, strong, or just won’t shift, or you’re tired all the time, pale or getting out of breath on the stairs, get a blood test. It’s a GP appointment, not an intervention. I know telling a doctor you eat clay feels mortifying. They’ve heard far weirder, and they can’t check for the right thing if they don’t know.
A quick word on the word pica. Clinically it’s classed as a feeding and eating disorder when it’s persistent and not part of someone’s cultural practice, and I know that label lands badly with a lot of you. I use it because it’s the word doctors use, not because I think anyone reading this needs fixing. Plenty of people crunch happily and on their own terms. If it ever starts to feel like the urge is running you rather than the other way round, that’s worth talking to someone about, the same as anything else would be. If it doesn’t, that’s your business.
For what it’s worth, here’s me. I’m a grown adult and I eat clay. I have done for years. I’m also anaemic and have regular iron infusions, and no, they don’t keep the cravings at bay, so I’m living proof the iron story isn’t as tidy as people like to think. Yes, that also makes me exactly the person the ‘already low on iron’ bit further down is talking about, and I’m not going to pretend otherwise. What I am is strict with myself. No more than a few tablespoons a day, and I lean towards treats over raw clays, purely because I like a softer crunch. That’s me. It’s not a recommendation and it’s not a rule. You can make your own mind up.
Your gut, your teeth and the rest of the list
Then there’s the less dramatic stuff. Clay can bind you up, and the more you have, the more likely that gets. Raw, unbaked earth can carry bacteria and parasite eggs. Researchers have also flagged that clay can bind medicines in the gut, not just nutrients, so if you take anything regularly, that’s worth a conversation with a pharmacist.
And teeth. Anyone who has bitten into a gritty batch slightly too confidently knows the feeling. Grit is grit, and enamel doesn’t grow back.
If you’re pregnant, this is the paragraph I most want you to read
Everything I’ve said about adults making their own call still stands. Pregnancy is just the one time it isn’t only your body in the equation.
Cravings in pregnancy are common, and clay has a long history as a morning sickness remedy in lots of cultures. It’s also exactly when lead does the most damage, because it passes straight to the baby. If you’re pregnant or trying, tell your midwife or GP about any cravings, get your iron checked, and please don’t use my shop, or anyone’s, as a pregnancy remedy.
If you’re breastfeeding and have been eating clay, the clinical guidance on calabash chalk is to stop the chalk, not the breastfeeding, but check with your GP or health visitor for your own situation.
Same goes for kids. Adults get to make their own call. Children don’t, and their bodies absorb lead far more easily than ours, so keep clay out of reach.
So, is it bad for you?
My honest read is that it depends on what’s in the clay, how much and how often, and who you are. Pregnant, a child, already low on iron, or on regular medication, and the risks stack up fast. For everyone else there’s no proven benefit, a real contamination risk, and a lot we still don’t know. Almost every review I read for this ended the same way: not enough research.
Weigh that up however you like. You know your body and your reasons better than I do.
If you do choose to crunch, here’s what I’d want you to have in your corner:
1. Ask sellers, me included, for heavy metal test results, and treat “lab-tested” without a certificate as a claim rather than a fact.
2. Get your iron checked if the cravings are new, strong or won’t go away.
3. If you’re pregnant or trying, talk to your midwife or GP before anything else.
4. Keep clay away from children.
5. Listen to your body. Stomach pain that won’t settle, constipation that won’t shift or tiredness you can’t explain are reasons to see a doctor, not to push on.
I’m not going to tell you what to do. This community gets told what to do, and what to be ashamed of, more than enough already. But not judging people and pretending everything is fine are two very different things. What I can do is give you the boring truth and trust you to do something sensible with it.
That’s what treating people like adults actually looks like.
Ta x
Disclaimer
My clay and chalk products are natural materials sold for sensory, hobbyist and ASMR use. They’re not certified food-grade, and I don’t sell them as food, supplements or medicine. Unless a listing says otherwise, please don’t assume a product has been tested for contaminants. This article is general information based on my own research and experience, not medical advice, and I’m not a doctor or nutritionist. If you’re pregnant, trying to conceive or breastfeeding, please speak to your midwife, GP or health visitor before consuming any non-food material. If you have any concerns about pica, geophagia or ingesting non-food materials, please speak to a GP or another qualified healthcare professional.
Sources and further reading
• Food Standards Agency warning on calabash chalk (2002, via NutraIngredients)
• Public Health England alert on calabash chalk, GOV.UK
• Food Safety Authority of Ireland, advice on calabash chalk (May 2026)
• FSA warning on clay-based drinks containing arsenic and lead
• FDA warning on Best Bentonite Clay
• FDA warning on Bentonite Me Baby
• Kaolin clay anaemia: a case report (PMC)
• Medicine beneath your feet: risks and benefits of geophagy (Cambridge)
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