Our expert reveals calcium bentonite clay vs sodium bentonite clay for skin & internal use, the difference between sodium and calcium bentonite and their myths.
Like many of you, I have wondered about using sodium or calcium bentonite clay for face and internal use. Through my findings, I have discovered that both calcium and sodium bentonite clay are suitable for skin and internal use provided that they are clean, pure clay with NO fillers and are certified as food grade bentonite clay (this should always be stated on the packaging).
When I first started looking into using bentonite clay for my skin and internal use, like many others, was led to believe that calcium bentonite clay was the only clay that should be used internally and that sodium bentonite clay was only suitable for external use. That is simply not true.

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This article helps to demystify the difference between sodium bentonite and calcium bentonite clay for face, skin as well as their internal uses.
Our expert, Mathew Mason from Australian Healing Clay weighs in to clarify the topics surrounding calcium bentonite clay vs sodium bentonite clay for skin, face and internal use.
Thanks, Matt!
What Is Bentonite Clay?
Bentonite Clay is classed as a smectite – swelling clay that has powerful adsorptive, drawing and absorptive properties. There are four types of Bentonite Clay, also referred to as Montmorillonite. They are:
- sodium
- calcium
- magnesium
- potassium
They are identified accordingly based on the higher amount of one of these exchangeable ions ie. sodium, calcium, magnesium, potassium.
The most widely marketed are sodium and calcium. This is probably only due to availability. All types are used in a variety of industries unrelated to health and beauty, such as industrial, agricultural, oil drilling (as a lubricant) and for road base.
Calcium Bentonite Clay Vs Sodium Bentonite Clay for Skin
Which Is Better?
It depends on what you are using it for. For surface skin cleansing purposes, it makes no difference which type of bentonite clay you use.
However, sodium bentonite clay may be better for detoxifying because it’s all about the ions!
What are Ions?
Ions are atoms that have gained or lost one or more electrons. A common atom has no electrical charge, but ions have a positive or negative charge.
So ions are attracted to each other by their opposite charge. An exchange takes place that is purely electrical. It does not discriminate, so it does not matter if the ions are sodium, calcium, magnesium or potassium.
For example, arsenic has a positive charge and is looking for a negative charge to balance its electrons. Because all types of bentonite have negatively charged ions they will bond with arsenic or any other positively charged particle.
This is how clay can be used as an effective cleansing or detoxing agent. It binds to positively charged heavy metals or toxins and locks them away.
This is called adsorbing. Sometimes you may find articles that use the term absorbing when trying to explain the ion gathering properties of bentonite clay. This is not the correct term to use in that case.
Furthermore, sodium bentonite clay contains calcium as an exchangeable ion whereas calcium bentonite contains sodium as an exchangeable ion.
To convert calcium bentonite to sodium bentonite just add a small amount of salt to a cup of clay and it will have more sodium exchangeable ions. That amount can be a ratio of about 1:5 or 1:6. It doesn’t have to be an exact science, so it can be about 50-60ml (about 1.6 – 2 oz). Be sure to use pure fine sea salt to avoid introducing unwanted elements into your mix.
One factor that could make a difference between sodium bentonite and calcium bentonite is the conductivity of the substance. For example, sodium is a better electrical conductor than calcium so there may be an advantage in that regard.
In any case, if one was to choose between sodium or calcium bentonite clay for internal use, both types of bentonite are considered to be abundant with exchangeable negative ions and that’s a positive for us!
Calcium Bentonite Clay Vs Sodium Bentonite Clay Mineral Content
The lists of minerals that make up the different types of Bentonite are very similar. However, given they are natural substances, each varies in colour and texture and each deposit of clay has its own unique mix.
For the purposes of using clay as a cleansing agent, knowing the mineral analysis is of no practical advantage as there is no way of utilising this information.
Conversely in agriculture knowing the mineral make up of clay deposits in a field helps the farmer prepare the soil for crops. Soil that has too much clay is poor for growing things and needs to be broken down or dissolved using a clay breaker such as gypsum or lime.
This breaks the clay down into its individual minerals which then become part of the growing soil. It is important to know which minerals are present in the soil and which are deficient so as to produce healthy crops.
Sodium or Calcium Bentonite Clay for Internal Use: Which is Better?
There is growing interest in the idea that bentonite clay has merit as a mineral supplement and the notion is increasingly being included in marketing.
However, the test results we have done and this research helps to confirm that the bentonite clay minerals are not bioavailable.
They are not able to be absorbed through the skin when applied topically. Nor is our digestive system capable of breaking clay down into individual minerals that can be absorbed by the body.
It has no value as a mineral supplement.
Which makes sense because if we could in fact digest it, we would forfeit its cleansing capabilities.
The benefit lies in clay remaining intact as it passes through our system attracting and adsorbing toxins and locking them away.
Consequently, if our digestive system is clean and functioning optimally then it follows that more efficient nutrient uptake will occur.
What Are The Qualities Of A Good Bentonite Clay?
The first thing to know is that the clay you purchase is bentonite clay because these are classed as smectites, a type of swelling clay that has the ability to adsorb toxins and pollutants at a high rate.
70-90 cation exchange is ample.
It is important to choose volcanic clay and of course it must be pure and clean clay with nothing added.
Some clays can have buffers and fillers so make sure to choose one that states they are 100% pure bentonite clay.
If taking it internally it must be stated on the label that it is food grade and of edible quality.
The bentonite clay we offer at Australian Healing Clay is a unique sodium magnesium bentonite that is volcanic clay having a cation exchange of 90/meq.
It occurs with high natural purity that satisfies food standards as safe to ingest.
It is BP grade – suitable for use with naturopathic and pharmaceutical medicines. Sun dried and dry milled into fine powder (45 microns).
No other processing or treatment is done.
It does not clump heavily like some bentonite making it easy to work with.
When hydrated it has a soft velvety texture and produces a very smooth paste.
French Montmorillonite clay which is actually sodium bentonite has been commonly used by Europeans for many decades. French naturopaths have written about it and recommend it for a lot of applications.
What Is The Importance Of Screen Mesh Size In Bentonite Clay?
The screen mesh size refers to the milled or granular size of the finished product. It is a measurement of the fineness of the powder.
Usually the finer the powder the quicker it will hydrate.
The mesh size does not affect the performance of the clay. It is the fine particle size of
Bentonite, meaning molecular size that provides a large surface area for absorption and is what separates it from other clay.
Australian 45 micron mesh size = USA 325 screen mesh.
✅ Recommended reading
“Energy to Heal” by Wendell Hoffman
“The Healing Clay” by Michael Abehser
“Our Earth Our Cure” by Raymond Dextreit
My Experience Using Sodium Bentonite Clay Internally
I’ve been using bentonite clay for quite a few years now, and to be honest, I’d come across the article that misled the whole internet into believing that calcium bentonite was the only safe clay to ingest as well. I actually didn’t find out until quite some after I’d started using the brand of clay that I’ve always used, that it was in fact sodium bentonite clay!
I chose to use my clay in the first place because it was food grade, and it seems to me that many of the food grade clays available, are in fact sodium bentonite (even if they don’t specify that on the packaging).
I’ve seen discussions around the whole sodium vs calcium bentonite clay thing online and there is soooo much mis-information. Clearly there is a lot of confusion. I even saw someone telling others that there was no such thing as food grade clay! This is simply false.
The food grade sodium bentonite clay that I use has been thoroughly tested and approved for human consumption by Food Standards Australia & New Zealand. It is also approved for pharmaceutical use.
It is mined in Australia and after mining, it is sun dried and dry milled into a fine powder.
That is all that is done to it. It is pure earth.
It contains no fillers or anything else and some clays do. So beware!
My advise is simple. If you want to drink clay, eat clay or otherwise use bentonite clay internally, always make sure that what you’re buying is food grade clay, otherwise you really have no idea what you’re consuming.
My Personal Uses For Bentonite Clay
I always have bentonite clay on hand these days. It’s great for detoxing – internally and/or by using it in the bath. It also makes a great face mask. But you know what? There’s a whole lot more to bentonite clay than that.
For example when I go on holiday, or even away for a weekend, I take some with me in a small container. Why? Because it can be a real life saver when the unexpected happens…

For example, I’ve used bentonite clay:
- On bites and stings (almost instant relief)
- On boils
- On injuries by making a poultice
- For diarrhoea
- For stomach upsets
- When I’ve been a bit suspicious about what I’ve eaten (food poisoning risks)
- On splinters or any time a ‘drawing action’ is required
- On strange skin ‘things’ – lumps, bumps and things that look a bit ‘suss’
- On verrucas
- In my home made bentonite clay tooth powder
Bentonite clay has so many uses and it’s doesn’t ‘go off’. Keep some on hand and it’ll be there whenever you need it.
Calcium Vs Sodium Bentonite Clay for Skin And Internal Use Summary
In this article, we hope we have revealed the difference between sodium bentonite and calcium bentonite clay for face, skin and internal use. Whether you use sodium or calcium bentonite clay for internal use, you must ensure that it is a food grade version, as labelled on the packet.
When it comes to clay quality it is all about the Ions: 70-90 cation exchange is ample.
Sodium bentonite may have an advantage for detoxifyng as it is a better electrical conductor. However, calcium bentonite can be converted to sodium bentonite by adding a small amount of salt.
The minerals in clay are NOT bioavailable. We do not digest it. It passes through our digestive system undigested.
The finer the molecular (micron mesh size) the more effective the clay is for detoxing. The finer the screen mesh size, the easier it will mix with water and hydrate.
Clays are more effective when well hydrated. (Mix well and leave to sit for as long as possible for best results before drinking or using).
Dear Sue,
When I saw your first video, my world became a better place.
While I’m much older than you (66), your story of your experience is almost identical to mine. I’m almost embarrassed to say I watched the video multiple times, just because it made me feel better, and our stories are uncannily similar.
I recently was tested, and given a diagnosis of Pyrroluria and/or Copper/Zinc imbalance (I don’t really care what they call it, the symptoms and treatment are the same. For mainstream docs (including my supremely unhelpful daughter), I call it Copper/Zinc imbalance, which they feel comfortable with since there are blood tests–Oh, how they love their blood tests. However, for everyone except MDs and some DOs are call it Pyrroluria.
Finally, after being misdiagnosed AND INCORRECTLY TREATED for RA, Lupus, Hashimotos, Depression–with sometimes extremely toxic drugs, like Prednisone, Methotrexate (the jury’s out on antidepressants). (No doc! There MAY appear to be depression, but ANXIETY is the hallmark of my disease, as it has since my first memories of childhood). Strong, body-tensioning, exhausting anxiety and tension have defined my life. However, I did manage to make some adjustments along the way, psychotherapy, psychedelics (in college–they work, this was the most serene, socially rewarding, and spiritually unfolding time of my life), super-exercise, pot (sorry folks, I confess. It is a safer and more effective drug for what I have than anything else–I don’t care if I get arrested, it’s still worth it.)
Anyway, I don’t want to get off track. I’d like to ask you a lot of questions, but I sense you’re busy with the book. If you need any help with it (research, proof-reading, style, clarity, grunt work, whatever), just call or FaceTime, or text or email me
Hi Dave. Unfortunately most mainstream doctors know little if anything about Pyroluria, but some do, and for the existence of those doctors, many of us are thankful. I know there are so many people (old and young) who remain undiagnosed and spend most their lives looking for answers. I feel for those who end up on the anti-depressant, mental illness roundabout, because for them, life can really get out of control. It’s funny that drugs were helpful for you. For me, even pot just made me more anxious so I gave up trying that when I was quite young!
Oh and I’ve removed your contact details as I didn’t think it best to leave them on there for the world to see. 🙂
Thanks for the feedback
Sue
Hello, I mm here just to gain info regarding clays, I read in and found the conversation interesting!
I have never heard of that disease , I’m sorry it exists and sounds like hard to diagnose properly .
My ailment is nerve damage caused by a back surgery that went terribly wrong. That’s about that so how to live with chronic pain . I have to agree, for the “Make me jump off the bed” muscle spasms which seem more like labor I. Their. Timing of pain , MJ has been the only help . I have been given so many different , pills, which include all from A-Z and “Pill Cocktails” which my surgeon seemed to enjoy congeriing up! Although I didn’t really appreciate passing out and losing an entire day on the floor with a lump on my head! I just stopped taking any.
I began the MJ experiment and found that ingestinMJ Butter to be the most effective pain/muscle spasm reliever of all. I don’t enjoy having to feel “Altered” to be comfortable I am thankful there is an option! Good luck to anyone who’s suffering and searching, I will say, be very careful in regard to pharmaceuticals mixed together, it can be a very scary experience which is also an up side to MJ. One herb. I do find that the Indica strain for me is most effective for nerve pain. Sativa is another strain and makes me tend to focus more on the pain than anything else. Everyone is so different. Peace. Health.
I have a quick question that I hope you can still answer. Is there a difference in the granular and powder clay?
Hi there. I’m sorry but I’ve not heard of granular clay. I’d imagine that it might be harder to take or use as it may not mix as readily with water, but that’s just an assumption on my part as I’ve only used powder. Always make sure your clay is food grade though if you’re using it internally.
Sue
Hi,
What is the maximum dose one can take of this clay?
ThanX
Hi there. I’m not sure what the maximum dose would be, or even if there would be a max dose. The usual amount is 1 or 2 tsp a day in water. If you have more it’s probably not going to have any added beneficial effect, but probably won’t do much harm either (might make you constipated or cause some digestive discomfort maybe?) because it’s simply just clay. Sorry I don’t have a more specific answer, but I hope that helps.
Sue
Hi Sue,
As a geo by training I am fascinated by the different uses of materials from the earth. That said, I did in the past do some analysis work on sodium Montmorillonite for use with race horses. Volcanic sourced vs marine sourced clays appear to be different in their respective minor elements suite and each elements concentration. The take away is that some of these sources have levels of toxins much higher than expected in humans, even to the level of toxicity for humans. So, I ask, can you point me to any randomized double blind placebo controlled trails demonstrating efficacy?
An anecdote is that the parrots of South America eat clay with apparent positive effect.
Thank you,
Jesse
Hi Jesse. I don’t know of any randomized double blind placebo controlled trials on bentonite clay – but that’s not surprising really. Unfortunately natural products such as clay don’t make the massive profits that pharmaceutical drugs do and so there isn’t the motivation or money to pay for trials. Therefore we, the consumer, just have to use our common sense, our intuition or ‘knowing’ about what’s real and good for us and go with that. I personally have used this clay off and on for years with only positive effect and I’ve seen it do some amazing things when used topically. That’s good enough for me. I don’t need millions of dollars worth of studies to tell me it’s good stuff! 🙂
This a wonderful article and answered many questions for me. Thank you so much for all this clearly explained information.