IngredientsClinoptilolite is a naturally occurring mineral belonging to the zeolite family — crystalline, hydrated aluminosilicates with an open-framework structure. It is a natural zeolite composed of a microporous arrangement of silica and alumina tetrahedra. Its accepted complex chemical formula is (Na,K,Ca)2–3Al3(Al,Si)2Si13O36·12H2O, forming as white, green to reddish tabular monoclinic tectosilicate crystals. An alternative representation used in the literature is (Na2,K2,Ca)3Al6Si30O72·24H2O, though the exact composition shifts depending on where it is mined.
The mineral's name was proposed in 1932. Scheler proposed the name clinoptilolite because of the chemical similarity between clinoptilolite and mordenite (ptilolite), even though clinoptilolite is today considered the most common and abundant natural zeolite. A historical misconnection with heulandite arose because of the monoclinic structure of clinoptilolite; in 1934, Hey and Bannister concluded that clinoptilolite was simply a silica-rich heulandite based on similarities in their X-ray diffraction patterns. Formally, clinoptilolite is classified within the heulandite group; it is the most abundant natural zeolite.
It forms crystals with a Mohs hardness of 3.5 to 4 and a specific gravity of 2.1 to 2.2. Clinoptilolite is somewhat soft and forms platy, nearly transparent crystals of monoclinic symmetry; it is typically colourless in thin sections, but colours such as brown, pink, or red may occur owing to the presence of impurities such as iron oxide.
Clinoptilolite possesses a three-dimensional framework composed of tetrahedra formed by silicon (Si) and aluminum (Al) atoms, and this framework contains well-defined pores and channels that enable the selective adsorption of molecules based on size and polarity. Each tetrahedron comprises a core silicon or aluminum atom surrounded by four oxygen atoms; incorporating aluminum inside the framework generates a negative charge, which is neutralized by cations such as Na+, K+, Ca2+, and Mg2+ situated in the channels and pores of the zeolite structure. Clinoptilolite possesses relatively wide pores and channels, typically measuring 0.3–0.4 nm in diameter, facilitating the selective adsorption of molecules according to their size and shape. Its structure consists of an outer framework of silica and alumina tetrahedra, within which water molecules and exchangeable cations such as calcium, potassium, and sodium migrate freely.
Clinoptilolite exhibits thermal stability up to 800°C (contingent on origin), enabling it to preserve its structural integrity during thermal processing such as drying or heating. Sodium levels in clinoptilolite are generally higher than potassium levels, as is the case with the San Bernardino Barstow Formation in California, but there are sources that are potassium-rich and have minimal sodium.
Clinoptilolite commonly occurs as a devitrification product of volcanic glass shards in tuff and as vesicle fillings in basalts, andesites, and rhyolites. The predominant zeolite precursors worldwide are acid to intermediate volcanic glasses from ashfall tuffs interbedded with lacustrine sediments, from vitroclastic tuffs in volcanic rocks, or from hydrothermally altered vitrophyres and vitroclastic tuffs. Large sedimentary deposits of natural zeolites were revealed by geological discoveries in the late 1950s in countries including Australia, Bulgaria, Canada, Cuba, Georgia, Hungary, Italy, Japan, Mexico, Romania, Russia, Serbia, Slovakia, Turkey, Ukraine, and the USA.
In Europe, the abundant clinoptilolite-bearing deposits are located in Slovakia and Ukraine, where clinoptilolite mineralization occurs in volcanic tuffs. Additional European deposits are found in Turkey, Hungary, Slovenia, Italy, Romania, and Serbia. In the United States, clinoptilolite deposits are particularly abundant in western states, where they form extensive reserves in sedimentary tuffs; notable locations include the San Simon Valley in Arizona, Ash Meadows in Nevada (with proven reserves exceeding 50 million tons), the Barstow Formation in California, and Hoodoo Peak in Wyoming.
World production of natural zeolites in 2018 was estimated at approximately 1.1 million metric tonnes, with China producing 300 kt, Korea 120 kt, New Zealand 100 kt, the United States 95 kt, Turkey 70 kt, and Cuba 57 kt. More than 80% of the world's zeolite production is of the clinoptilolite type.
Clinoptilolite is commercially available in several physical and processed forms:
Zeolite-bearing minerals were already known to mankind over the centuries; they were used, for example, to build pyramids and temples in Mexico and churches and houses in Cappadocia. As a therapeutic substance, the documented history of clinoptilolite per se is limited; however, the broader category of zeolitic clays and volcanic mineral earths has a multi-century record of medicinal use across several cultures.
Historically, zeolites like clinoptilolite have been valued in traditional medicine and folk remedies across various cultures. Ancient civilizations in Asia and Eastern Europe harnessed powdered forms of zeolite-rich clays to address digestive discomfort, promote detoxification, and as topical applications for wounds and skin irritations. The practice of consuming fine mineral earths and clays for gastrointestinal complaints — sometimes termed geophagy in ethnographic literature — is documented across multiple traditions, and zeolitic volcanic deposits formed a component of such earths in regions where they were geologically accessible.
In Central America and the Yucatan peninsula, zeolite-containing volcanic tuffs were quarried for construction of pre-Columbian structures, and their properties as adsorbent and deodorizing materials were exploited in practical applications prior to Western mineralogical classification.
In Eastern Europe and the Balkans, deposits of clinoptilolite-rich rock — particularly in the Rhodope Mountains of Bulgaria and the Carpathian-Pannonian region — were recognized by local populations for their properties in filtering water and improving livestock health, uses that predate formal scientific investigation.
It is important to note that the majority of traditional claims about clinoptilolite specifically cannot be precisely dated or culturally attributed in the peer-reviewed literature reviewed for this article. The formal scientific study of clinoptilolite as a medicinal agent began in earnest only in the late 20th century, primarily in Croatia, Germany, Austria, and Slovakia.
The defining property of clinoptilolite, from both industrial and biomedical perspectives, is its high cation exchange capacity (CEC). Incorporating aluminum inside the framework generates a negative charge, which is neutralized by exchangeable cations; this characteristic enables clinoptilolite to exchange cations, making it beneficial for water treatment and soil enhancement. In a biological context, through an ion-exchange process, the existing cations of calcium or sodium in the structure can be interchanged with heavy metals such as lead, nickel, arsenic, and cadmium. Use in industry and academia focuses particularly on clinoptilolite's strong exchange affinity for ammonium (NH4+).
Beyond ion exchange, clinoptilolite functions as a molecular sieve through physical adsorption. The framework contains well-defined pores and channels that enable the selective adsorption of molecules based on size and polarity, with pore sizes typically ranging from 0.3 to 1 nm, varying according to the specific type of zeolite. The dehydrated mineral has the properties of a molecular sieve that selectively extracts nitrogen from a stream of air, leaving the effluent enriched in oxygen. In the gastrointestinal tract, this mechanism is proposed to underlie the adsorption of mycotoxins, bacteria, ammonia, and various organic toxicants; clinoptilolite has been shown in studies to help bind and neutralize mycotoxins, which are toxic metabolites of fungi, and other clinically relevant substances.
A secondary mechanism proposed for clinoptilolite's biological effects involves modulation of the cellular antioxidant system. Clinoptilolite is a highly porous natural mineral with a capacity to eliminate metals from living organisms, mainly by ion-exchange and adsorption, thus providing detoxifying, antioxidant, and anti-inflammatory medicinal effects. In lead-poisoned mice, clinoptilolite increased the activity of key protective enzymes in brain tissue, including catalase, superoxide dismutase, and glutathione peroxidase. This is thought to result partly from removal of pro-oxidant heavy metal ions, and partly from direct surface-mediated effects on reactive oxygen species (ROS) levels.
Several in vitro and animal studies have explored the hypothesis that clinoptilolite may exert antitumor effects. In vitro tissue culture studies showed that finely ground clinoptilolite inhibits protein kinase B (c-Akt), induces expression of p21WAF1/CIP1 and p27KIP1 tumor suppressor proteins, and blocks cell growth in several cancer cell lines; these data indicate that clinoptilolite treatment might affect cancer growth by attenuating survival signals and inducing tumor suppressor genes in treated cells. As clinoptilolite particles are negatively charged polyanions, they might target cancer cells and induce additional oxidative stress upon entrance into the cytoplasm through hydrogen peroxide activation and increased production of ROS; in previous in vitro experiments on tumor cells, antitumor effects were attributed to the modulation of EGF-R, protein kinase B (PKB)/Akt, and nuclear factor κB (NF-κB) signaling. These mechanisms remain strictly preclinical and have not been validated in controlled human trials.
Although oral aluminum bioavailability is known to be increased by acidic pH in the human intestine, in the case of clinoptilolite tuff it may be decreased because it is a silicon-containing compound that releases certain amounts of dissolved silica; data have been provided on the ability of silicon-rich mineral water or silicic acid to remove aluminum from the human organism, and this Si–Al relationship has been recognized as the main evolutionary mechanism for fighting the ecotoxicity of aluminum in living organisms.
One of the better-studied human applications of clinoptilolite involves its effects on intestinal barrier function. A factor that contributes to the pathophysiology of inflammatory bowel disease is enhanced permeability of the epithelial barrier, which allows for the leakage of bacterial fragments; prolonged administration of clinoptilolite to human subjects has been shown to induce changes in surrogate markers indicative of an improved epithelial barrier.
A key human study examined zonulin — a protein whose elevated serum levels indicate loosening of tight junctions — in aerobically trained athletes. In a 12-week, placebo-controlled study of aerobically trained athletes, those taking a zeolite supplement saw their zonulin concentrations drop by almost 30%, falling from above the clinical cutoff (61.2 ng/mL) into the normal reference range (43.8 ng/mL), while the placebo group's levels barely changed (56.1 to 59.6 ng/mL). This finding is particularly notable because intense exercise is known to temporarily increase intestinal permeability. The gut-barrier research from this study is considered promising but preliminary.
Clinoptilolite has been evaluated in patients with irritable bowel syndrome with predominant diarrhea (IBS-D) in a randomized controlled trial. Purified clinoptilolite-tuff (PCT), approved by the FDA for use as a dietary supplement under the brand name G-PUR®, was investigated in a randomized, placebo-controlled, double-blind pilot study of 30 patients with IBS-D diagnosed according to Rome IV criteria; following a 4-week run-in phase, 14 patients were randomized to receive a 12-week treatment with G-PUR® at a dose of 2 g three times daily, and 16 patients received placebo.
An improvement in daily abdominal pain was noted in 94% vs 83% of patients (P = 0.0353), the median number of days with diarrhea per week decreased by 2.4 days vs 0.3 days in the G-PUR® and placebo groups respectively, positive trends were observed for 50% of responders in the Bristol Stool Form Scale, and only 64% in the G-PUR® group compared to 86% in the placebo group required rescue medication intake during the study. The gut microbiome analysis of the patients revealed a trend towards greater alpha and beta microbial diversity in the treatment group, which has been associated with a healthy gut microbiome and improved symptoms; this change was not observed in the placebo group, though larger cohorts would be needed to identify a causal relationship. The study concluded that the PCT product G-PUR® demonstrated safety and clinical benefit towards some symptoms of IBS-D, representing a promising novel treatment option for these patients.
Evidence strength: Positive signal from a single small-sample (n=30) double-blind RCT; the pilot-scale design and small numbers limit generalizability.
The possibility that administration of clinoptilolite mitigates the course of dextran sulphate sodium (DSS)-induced bowel inflammation has been explored; in murine DSS-induced colitis models, clinoptilolite particles were readily identified in the intestinal lumen by transmission electron microscopy. Findings from this murine model must be interpreted cautiously and have not yet been confirmed in controlled human trials in inflammatory bowel disease.
The most mechanistically plausible area of human application is the reduction of heavy metal burden. A clinical study on 33 men evaluated the ability of zeolite clinoptilolite to increase heavy metal urinary excretion; to be included in the trial, participants had to test positive above a predetermined threshold for at least four of nine metals in a urinary test panel (aluminum, antimony, arsenic, bismuth, cadmium, lead, mercury, nickel, and tin). In a 12-week trial, arsenic levels dropped significantly in supplemented participants; in a short-term 28-day study, participants who started with elevated mercury and cadmium levels saw statistically significant decreases in both metals.
A 2022 study published in Frontiers in Medicine examined three clinical trials with different supplementation durations (28 days, 12 weeks, and 4 years). Effects of the registered and certified clinoptilolite material PMA-zeolite on selected mineral and metal levels were determined by standard biochemical methods and ICP-MS in the blood of subjects enrolled in three clinical trials: short-term (28 days, Mineral Metabolism and selected Blood Parameters study — MMBP), medium-term (12 weeks, Morbus Crohn study), and long-term (4 years, Osteoporosis TOP study) supplementation. Aluminum levels were statistically significantly lower in PMA-zeolite-treated patients in comparison with placebo within the osteoporosis TOP study, including after the end of the fourth year of the clinical trial, confirming the aluminum-detoxification properties of clinoptilolite materials.
In several recent clinical trial studies on humans with natural clinoptilolite material (PMA zeolite), it has been shown that preloaded metals do not enter the bloodstream from the intestine, but that the observed fluctuations of metal levels in the blood are a consequence of the activation of detoxification processes from various body compartments.
In animal studies: modified clinoptilolite led to a nearly 48% reduction in cadmium accumulation and a 30% increase in cadmium excretion in the clinoptilolite-plus-cadmium group compared to the cadmium-only group; erythrogram and leukogram parameters returned to near-normal levels, with reductions in malondialdehyde (MDA) and increases in glutathione (GSH) observed by the end of the experiment.
Evidence strength: Human evidence shows real but variable effects on heavy metal levels, with the strongest results in people who had elevated levels to begin with. Studies are generally small and have heterogeneous designs. The human evidence shows real but variable effects on heavy metal levels, with the strongest results in people who had elevated levels to begin with.
Preliminary in vitro studies suggest that clinoptilolite may exert antitumor effects. The most-cited early experimental work in cancer-bearing animals showed: treatment of cancer-bearing mice and dogs with micronized zeolite clinoptilolite (MZ) led to improvement of the overall health status, prolongation of life span, and decrease of tumor size in some cases; it also reduced lipid peroxidation in the liver of mice. MZ reduced the metabolic rate of cancer cells and increased binding of 4-hydroxynonenal (HNE) to albumin in vitro; it selectively reduced generation of HNE in vivo in tumor stroma after doxorubicin treatment while leaving onset of lipid peroxidation intact in malignant cells; combined treatment with doxorubicin and MZ resulted in strong reduction of pulmonary metastasis count, increasing anticancer effects of doxorubicin.
Evidence strength: Strictly preclinical (cell-line and animal data). There is no credible evidence from controlled human trials for cancer treatment claims associated with zeolite supplements. These findings require replication in rigorous human studies before any clinical conclusions can be drawn.
Clinoptilolite has demonstrated the ability to modulate immune responses, particularly in the gut and on the skin. Clinoptilolite supplementation has been observed to increase the activation of B lymphocytes (CD19+), T helper cells (CD4+), and activated T-lymphocytes (HLA-DR+), while reducing natural killer (NK) cell (CD56+) counts. These findings are drawn from small preliminary studies and require confirmation in larger trials.
A preliminary efficacy study performed on patients with dyslipidemia has shown a positive effect of clinoptilolite supplementation on lowering total lipid count and LDL cholesterol. This finding is described as preliminary in the 2018 critical review published in Frontiers in Pharmacology; confirmatory controlled trials have not been identified in the sources reviewed here.
A 2025 review in PMC evaluated the structural characteristics, therapeutic mechanisms, and clinical applications of zeolites — including clinoptilolite — across skin infections, wound healing, acne management, and cosmetic dermatology. Zeolites demonstrated broad-spectrum antibacterial and antifungal efficacy, enhanced antioxidant activity, and biocompatible drug delivery in various dermatological models; formulations such as zinc–clinoptilolite composites for acne represent innovative avenues for targeted therapy. Evidence at this time is largely from experimental models; clinical trial data in dermatology are sparse.
The following dosages are drawn directly from identified clinical studies and should not be interpreted as recommendations:
Clinical trials spanning up to four years of daily use did not report serious adverse effects. The mineral is not absorbed into the bloodstream; it passes through the digestive tract and is excreted, taking whatever it has bound along with it.
Zeolite clinoptilolite (sodium aluminosilicate) has FDA GRAS (Generally Recognized as Safe) status as of April 2014 (FDA 21 CFR §182.2727 and food additive E-number E-554). In the United States, clinoptilolite is classified as "generally recognized as safe" (GRAS) for use in animal feed, and it has regulatory approval as a medical device or supplement in the European Union.
The European Commission has authorized the use of clinoptilolite of sedimentary origin as a feed additive for all animal species, in the category of technological additives in the functional groups of binders and anticaking agents. A 2025 EFSA FEEDAP Panel concluded that clinoptilolite of volcanic origin is considered safe at 20,000 mg/kg complete feed for use in feed for poultry for fattening and reared for laying/reproduction, ornamental birds, piglets (suckling and weaned), and pigs for fattening. The Panel concluded that the use of clinoptilolite of volcanic origin is safe for consumers and the environment.
Earlier, EFSA released an expert opinion on the safety of natural zeolite clinoptilolite in vivo and evaluated and proved zeolite-clinoptilolite non-toxicity for animal feed at doses of 10,000 mg/kg. Oral consumption of this type of zeolite, due to its extreme chemical stability, in EFSA's opinion does not represent a potential risk for in vivo applications.
Clinoptilolite is recognized as the only safe zeolite for medical use, owing to its well-established benefits for animal and human health and performance.
The basic structure of clinoptilolite is considered to be biologically neutral and non-toxic. A critical feature underlying its safety profile is its non-systemic action: the mineral is not absorbed into the bloodstream; it passes through the digestive tract and is excreted, taking whatever it has bound along with it. Clinoptilolite loaded with potential toxicants in the intestine is then excreted along with those toxicants.
The main practical concern is that clinoptilolite does not only bind harmful substances; its ion-exchange process can also interact with beneficial minerals and potentially with medications taken at the same time. The 2022 Frontiers in Medicine clinical study, which encompassed up to 4 years of monitoring, tracked both toxic and essential element levels. Clinically significant depletion of essential minerals was not reported as a major finding in these monitored studies; however, the possibility of interaction remains of theoretical concern, particularly with chronic use.
A frequently raised theoretical concern is potential aluminum leaching from clinoptilolite's aluminosilicate framework in the acidic environment of the gastrointestinal tract. Although oral aluminum bioavailability is known to be increased by acidic pH in the human intestine, in the case of clinoptilolite tuff it may be decreased because it is a silicon-containing compound that releases certain amounts of dissolved silica. Studies show no evidence of aluminum toxicity or other concerns related to heavy metals from clinoptilolite supplementation in the trials reviewed. Nonetheless, toxicology studies of this material are scarcely covered in the scientific literature, and longer-term systematic monitoring data remain limited.
Some concerns have been raised about the possible lead leakage from natural clinoptilolite materials into the intestine; however, extremely high affinity of clinoptilolite to lead has been documented, where sorption of lead and cadmium on natural clinoptilolite was shown to be irreversible or very slowly reversible, and particularly high in an acidic environment. These results were obtained in very simple in vitro models that may not adequately mimic human digestion, indicating the need for further in vivo study of this specific concern, particularly for raw or inadequately purified mineral products.
People with kidney disease should be cautious, as any additional mineral load could be problematic when kidney function is already compromised. This concern is based on the theoretical alteration of mineral excretion profiles; no dedicated clinical studies in renally impaired patients have been identified in the sources reviewed.
Given clinoptilolite's broad adsorptive properties in the gastrointestinal tract, concurrent ingestion with oral medications raises the theoretical possibility of reduced drug absorption. The standard recommendation in the clinical literature is to separate doses by at least two hours to avoid any interference with absorption. This precaution has not been formally evaluated in dedicated pharmacokinetic interaction studies identified in the sources reviewed.
While oral exposure to clinoptilolite in supplement form is associated with a favorable safety profile in clinical trials, occupational inhalation of zeolite dust is a distinct concern not addressed by the supplement literature. Commercial supplement preparations are processed to eliminate inhalation risk; however, handling loose clinoptilolite powders in poorly ventilated settings could present a dust-related respiratory hazard.
Some products on the market have clinoptilolite content as low as 50% or even 40%, with the remainder being regular stone or clay. The quality and purity of the specific product matters significantly. Contaminant profiles (e.g., silica polymorphs, heavy metals from geological matrix) can vary between deposits and processing methods, reinforcing the importance of using well-characterized, certified materials in both research and consumer contexts.
Clinoptilolite materials showed a number of positive effects on health, including antioxidative, immunostimulatory, antidiarrheal effects, positive effects on bones, and anti-tumor effects, but their usage in humans has not been comprehensively evaluated in detail within large controlled clinical studies; accordingly, data on documented systemic effects on the human body are limited.
Health conditions that Clinoptilolite may help support.
Clinoptilolite is a naturally occurring zeolite mineral whose cage-like aluminosilicate lattice binds and traps heavy metals (mercury, cadmium, lead, arsenic, thallium) and mycotoxins via ion exchange in the GI tract. Clinical studies document reduced blood mercury and cadmium after 28-day supplementation, and improved blood arsenic after 12 weeks.
Clinoptilolite is the most biomedically relevant form of natural zeolite, a porous aluminosilicate mineral used for heavy metal binding via ion exchange. Studies demonstrate it binds aluminum, lead, cadmium, and other positively charged metals in the GI tract. It has been used in clinical and veterinary contexts as a GI metal binder and mycotoxin adsorbent.
Clinoptilolite is the most clinically relevant and best-studied zeolite form for mycotoxin adsorption, featuring a high ion-exchange capacity, structural GI stability, and a low aluminum-to-silica ratio preferred for human use. It binds aflatoxins, zearalenone, ammonia, and heavy metals in the GI tract and is used in purified form in commercial mycotoxin binder formulas. It is specifically noted for its high affinity for ammonia, which supports liver and kidney function commonly impaired in mold illness.
Body systems that Clinoptilolite may help support.
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