Smith had been drinking the tainted water for years before he learned that it was sending his levels of certain PFAS soaring. In 2022, the Silent Spring Institute, a nonprofit\u00a0health research organization, commissioned<\/a> a study that included Centerville.<\/p>\n Through that study, Smith learned exactly how much of the PFAS were circulating in his blood. In short, his levels were high\u2014in the case of one chemical, perfluorohexanesulfonic acid (PFHxS), his blood level was 14 times the national average (PDF)<\/a>. After he got the results, \u201cI was feeling pretty bad,\u201d he says.<\/p>\n And he\u2019s not alone. Following a hefty exposure, PFAS levels can take decades to return to baseline; people like Smith often feel like they\u2019re stuck carrying these toxic substances, which have been linked to health problems ranging from high cholesterol to cancer. Many people \u201cwant some sort of medical solution,\u201d says epidemiologist Shiwen Li from the University of Hawaii at Manoa, who studies the health impacts of PFAS.<\/p>\n Cholestyramine is a tangled ion-exchange resin. When taken orally, it lingers in the gut and swaps its chloride ions for negatively charged bile acids, binding them.<\/p>\n Cholestyramine, a cholesterol management drug that was approved in the US more than 50 years ago, may be just that. Over the past 4 years, three studies<\/a> have suggested that cholestyramine<\/a> can eject PFAS from the body<\/a>.<\/p>\n All three studies are preliminary, cautions Li, who was not involved in any of them. In his opinion, celebrating is premature. \u201cWithout larger clinical trials, we shouldn\u2019t be advertising that this is the solution.\u201d At the same time, based on his knowledge of biochemistry, he says the mechanism of how the drug would remove PFAS makes sense.<\/p>\n Smith sought out cholestyramine after finding publications in the scientific literature about its potential benefit for people with high PFAS exposure. Smith\u2019s gastroenterologist was familiar with cholestyramine and considered it safe, so he agreed to give Smith a prescription.<\/p>\n After about 8 months of taking cholestyramine, Smith has seen his PFAS levels drop dramatically. Two fluorinated chemicals became almost undetectable in his blood, and PFHxS dropped to about 30% of what it once was. \u201cIt was definitely a psychological boost,\u201d he says.<\/p>\n Cholestyramine is a powdered resin taken orally that sticks around in the gut for a while, and it\u2019s thought to lower PFAS levels the same way that it lowers cholesterol: by interrupting bile acids\u2019 round-trip voyage from the liver to the gut and back.<\/p>\n Normally, bile acids are made in the liver and then migrate to the gut, where they bind to fats and help the body digest them. Some fats can slow the body\u2019s breakdown of cholesterol, so lowering levels of those fats can lower cholesterol. Cholestyramine accomplishes this by binding complexes of bile acids and fats while they\u2019re in the gut, creating an insoluble matrix that leaves the body in feces. In the absence of cholestyramine, bile acids head back to the liver after they\u2019re done in the gut so that the body can reuse them.<\/p>\n But PFAS can get swept up into this cycle too. Some PFAS share structural features with fats\u2014namely, they both have long, neutrally charged tails and negatively charged heads\u2014so PFAS can also bind to bile acids and ride along as they cycle between the liver and the gut. By breaking that cycle, cholestyramine can capture PFAS, taking them out of the body and into the toilet.<\/p>\n Since at least the 1980s, researchers have suspected that cholestyramine could lower PFAS<\/a> levels, but scientists have only recently begun to test the idea rigorously. In a 2021 publication, Alan Ducatman, a long-time PFAS researcher at West Virginia University, followed up on the cholestyramine theory by reanalyzing data<\/a> from a seminal study that linked PFAS levels to numerous health problems<\/a>. He found that 36 of the study\u2019s 56,175 participants happened to be taking cholestyramine, and their levels of certain PFAS were reduced compared with levels in the rest of the population (Environ. Toxicol. Pharmacol. 2021, DOI: 10.1016\/j.etap.2021.103650). One PFAS in particular, perfluorooctanesulfonic acid (PFOS), \u201cjust really went away,\u201d Ducatman says.<\/p>\n Meanwhile, in Denmark, nephrologist and internist Morten Lindhardt from the University of Copenhagen and his colleagues tested cholestyramine\u00a0in a group of 45 people who were highly exposed to PFAS<\/a>. The forever chemicals got in their systems after they ate meat from cattle that were raised near a firefighting school. Half the participants took cholestyramine for 12 weeks while the other half went untreated, and then the two groups switched (Environ. Int. 2024, DOI: 10.1016\/j.envint.2024.108497).<\/p>\n Levels of various PFAS dropped by about 20\u201360% when study participants took cholestyramine. Levels in the untreated group dropped only about 3%, or, in some cases, rose slightly. \u201cThe effect of treatment was astronomical\u2014huge effect,\u201d Lindhardt says.<\/p>\n Around the same time, firefighters in Australia were starting to realize the extent to which firefighting foam might endanger their health. In response, in early 2018, the South Australian Metropolitan Fire Service launched a voluntary program to identify firefighters who had been highly exposed and offer treatment to them. Twelve firefighters chose to take cholestyramine, and their levels of PFOS and PFHxS seemed to drop about three times<\/a> as much as levels in those who went without treatment over the course of a year (Environ. Int. 2025, DOI: 10.1016\/j.envint.2025.109609).<\/p>\n It’s important to note, however, that the study in Australia was designed around the desires of affected people rather than around producing robust scientific findings, says toxicologist Ian Delaere, an author on the study and the director of the toxicology consultancy Expotox. Because of this design decision, the study is small and comes with many caveats.<\/p>\n For example, participants may have begun avoiding PFAS in their daily lives because they knew their levels were high, making cholestyramine look more effective than it actually is, Li says. But when you look at the results next to other recent studies, \u201cthey all seem to be heading in the same direction,\u201d Delaere says.<\/p>\n Cholestyramine often causes gastrointestinal side effects<\/a> such as nausea and diarrhea, and might cause the body to excrete fat-soluble vitamins. \u201cIt\u2019s not wonderfully pleasant, but it\u2019s not particularly dangerous,\u201d Ducatman says. Lindhardt thinks tinkering with the dose of cholestyramine and length of treatment could reduce the chance of side effects and limit how long users have to tolerate them.<\/p>\n But other experts warn that cholestyramine\u2019s initial effectiveness at lowering blood PFAS levels could be deceptive. Just because levels of PFAS drop in a person\u2019s blood doesn\u2019t necessarily mean they drop in all tissues, Li says. Over time, PFAS may leach out of tissues such as fat and into the blood, causing levels to go up again.<\/p>\n Whether reducing PFAS levels after a hefty exposure has long-term health benefits is a topic of discussion within the research community. It\u2019s possible that once the chemicals have entered a person\u2019s body, the damage has been done, and clearing them has little impact.<\/p>\n Lindhardt thinks that anyone who argues for the health benefits of using cholestyramine to speed up PFAS clearance is \u201con thin ice\u201d at this early stage in the research. He compares the situation to smoking: \u201cYour risk of having lung cancer is not eliminated the day after you stop,\u201d he says. But by the same logic, Delaere counters, telling a person not to use cholestyramine to reduce their PFAS levels would be like telling a smoker that there\u2019s no health benefit to quitting, which is clearly untrue.<\/p>\n There is some indication<\/a> that \u201cyour body can slowly cure itself\u201d after PFAS are cleared<\/a>, Li says. So far, the evidence centers around cholesterol levels, which go up in response to PFAS exposure. As PFAS levels drop, cholesterol levels also appear to return to normal.<\/p>\n Smith is hoping the same will hold true for his health problems. \u201cIf my levels come down, maybe some of these other issues I have will get better,\u201d he says. And even if cholestyramine doesn\u2019t live up to its promise, he and his friends are already contending with serious health problems, so \u201cwhat do we have to lose?\u201d he asks.<\/p>\n![\"A](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2026\/02\/(Feb-4-post-Cent-Sci-story)-PFAS-lowering-Cholesterol-drug---235893.jpg\")
\n A line structure of the molecule PFHxS, or perfluorohexanesulfonic acid.<\/p>\n![\"The](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2026\/02\/(Feb-4-post-Cent-Sci-story)-PFAS-lowering-Cholesterol-drug---235895.webp\")
\n The structure of a segment of a cholestyramine\u2019s matrix features trimethyl benzylamine salt groups and intermingled polymer chains cross-linked by benzene rings.<\/p>\n![\"A](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2026\/02\/(Feb-4-post-Cent-Sci-story)-PFAS-lowering-Cholesterol-drug---235894.jpg\")
\n A line structure of the molecule PFOS, or perfluorooctanesulfonic acid.<\/p>\n