Does your body need a parasite purge? Probably not

In 2008, Kurt started to experience things that hadn't bothered him before: dry skin, fatigue, irregular bowel movements and a white coating that formed over his tongue. For years, he saw both traditional doctors and holistic medicine providers, who recommended or prescribed certain treatments to help him feel better. But he didn’t see much progress.

To try and find a solution, he started researching his symptoms online, where he came across a forum of people reporting their experiences with parasite cleanses. Soon after, he bought a 30-day protocol, marketed to rid the body of parasites.

“Nothing was working,” Kurt, who is using his first name only for privacy reasons, told Salon in a phone interview. “I was kind of just willing to try anything.”

Parasite cleanses have been around for decades, but they have recently surged in popularity on social media, with influencers and companies endorsing products or homemade solutions that promise to rid the body of harmful intestinal worms. Many doctors say the likelihood of having an intestinal parasite in the U.S. is relatively low and recommend people see a health care provider to get tested for a parasite if they think they have one rather than turning to online therapies.

While many people report positive impacts when taking herbal supplements, these substances can come with side effects and contraindications just like pharmaceutical medications. Some of the ingredients included in these cleanses can be harmful when taken too frequently or at too large of a dose, and these formulations could also impact the natural balance of bacteria in the gut keeping us healthy. In any case, self-medicating with supplements online inherently carries its own risks, said Dr. Thomas Moore, an infectious disease doctor at the University of Kansas School of Medicine at Wichita.

“If someone does have a parasite, there is actual medicine to address those parasites,” Moore told Salon in a phone interview. “There is no need to go on the internet for it.”

The prevalence of intestinal parasites in the U.S.

Hundreds of parasites have the ability to infect humans, including lice, mites and ticks. However, parasite cleanses typically promise to purge the body of intestinal parasites such as tapeworms. 

The majority of intestinal parasites that have historically infected humans have been declining in prevalence and are currently rare in the United States, according to a 2023 review in Modern Pathology. Hookworms, for example, used to devastate communities in the South, but they were by and large eradicated with the introduction of indoor plumbing and urbanization.

Still, intestinal parasite infections do still occur in the U.S., and many disproportionately affect people with reduced access to health care like those living in poverty or immigrant communities. Some of these parasites like the microscopic cryptosporidium — usually transmitted through water or food that has been contaminated with feces, including raw milk — have become more common over the past decade, according to the review.

You may have heard of some of the more common intestinal parasite infections. Pinworms, for example, cause itchiness in the anus and primarily spread between young children and their families, affecting up to 15% of the population at any given time. Giardia, which causes diarrhea and can be acquired from drinking water from streams that has been contaminated, is estimated to affect 3.7% of the U.S. population.

Other intestinal parasites can have more severe side effects. Ascaris lumbricoides, a type of roundworm from pigs that has been reported in a few cases in humans, can cause issues with the lungs or growth problems in children in severe cases. However, there are medicines available to eradicate it.

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In general, intestinal parasite infections are far more common in developing countries, where deworming practices are sometimes performed on populations that are exposed to high levels of contamination that put them at risk. But that is not the case in the states, where exposure to raw sewage or other things that can transmit intestinal parasites are comparably low, said Dr. Carlos Chaccour, a tropical disease researcher at the Barcelona Institute for Global Health in Spain.

“In the U.S., which is highly urbanized and there are laws for sanitation, waste management, etc., the prevalence is substantially low,” Chaccour told Salon in a phone interview. “It’s definitely not a public health problem.”

Finding out if you actually have a parasite

In the case that someone is infected with a parasite, it’s important to get tested to identify which one it is, as each one has its own treatment protocol. 

Many people online say the tests used to diagnose parasites are inaccurate and prone to false negatives. While it is true that some infections could be missed in a single sample, the CDC recommends testing stool three times. In one study of refugees in the U.S., for example, the first stool sample detected 80% of cases, the second increased the sensitivity to 92% and the third detected the remaining cases. 

Additionally, other techniques are available to detect parasitic infections like blood tests, which vary based on the test but are generally even more accurate. One 2014 study found many different versions of these tests accurately detected the parasites causing pinworm close to 100% of the time.

Self-diagnosing parasites in your own stool can be tricky. For one, there are many different kinds that all look different, and evidence of parasitic infection can be excreted as parasitic larvae, which are microscopic. Some of the body’s natural processes can also mimic something that looks like an intestinal worm. 

Furthermore, some of these supplements can change stool in a way that makes it look like a parasite is being shed when it isn't, said Chris Brianik, a biologist who moderates a Reddit group about parasites where people commonly discuss cleanses. The intestines shed their lining periodically, which produces a mucus that can be visible in stool and may be misidentified as a parasite, he explained.

In two published case reports, two patients took the herbal supplement Mimosa pudica, which they had read online could “cleanse” gut parasites. However, the report concluded that “this substance clumps together in stool, causing long, stringy structures to form,” which made the patients think they were passing worms when they were not.

“These cleansers often just encourage that,” Brianik said. “They irritate the stomach lining and encourage mucosal shedding, and to the untrained eye, it looks like a parasite.”

Savina Bertollini, an herbalist in Marche, Italy, said she has worked with health care providers to treat people who were infected with a parasite while traveling. While some herbs have been effective in her experience, these supplements can cause side effects when taken long-term and are not “miracle pills,” she said.

Bertollini said she is skeptical of cleanses marketed for large numbers of people that are used in a “preventative” way without confirming that they have a parasite in the first place.

“Someone might indeed need a parasite treatment,” Bertollini told Salon in an email. But for someone who does not know whether they have parasites and has not consulted with a health care professional, using a cleanse they bought because of an ad on social media or something similar "could create negative health consequences,” she added.

Supplements are not without risks

Some of the ingredients in things marketed as a parasite cleanse online may contain things like dietary fiber, which are unlikely to do harm, said Sebastian Lourido, a biology professor at the Massachusetts Institute of Technology. 

“But if you are suffering from a real parasite infection, that is not going to help, and delaying treatment is probably going to be detrimental,” he told Salon in a phone interview.

Parasite cleanses contain a wide range of ingredients depending on the product, and much of the information about how these supplements impact the body is anecdotal. One small study found dried papaya seeds were associated with reduced intestinal parasites in Nigerian children. But the majority of studies looking at the effects of herbal supplements like these on parasites have been conducted in test tubes or culture dishes — not in humans. 

In addition to herbal supplements, however, some cleanses include ivermectin, an antiparasitic drug used to treat river blindness and elephantitis, which leads to the painful enlargement of body parts. While ivermectin has saved millions of lives around the world from conditions like these, taking these drugs without having parasites or without a doctor to help guide dosing can be dangerous, Chaccour said. 

In recent years, ivermectin has been caught up in misinformation circulating online: During the height of the COVID-19 pandemic, inaccurate claims that it cured the virus spread on social media, and many began using animal formulations in an attempt to treat COVID and even cancer. Despite concerns of misuse, legislation allowing ivermectin to be sold over-the-counter instead of requiring a prescription has recently passed in Idaho, Tennessee and Arkansas.

Moore said ivermectin was not the panacea some are making it out to be and that it is not a benign drug in large quantities.

“All drugs have risks and benefits,” he said. “If you're taking any drug, regardless of what it is to treat something that you don't actually have, then you're taking all of the risk and you get none of the benefit.”

Some substances in parasite cleanses may disrupt the microbiome: the balance of natural bacteria in the gut that helps digest food and keep the body healthy, Lourido said. Although scientists are still uncovering how the balance of bacteria in the microbiome impacts the body, upsetting this balance in the gut has been associated with changes to the immune and metabolic systems — and even mental health.

Many cleanses also recommend eating certain foods or restricting one’s diet, which could also disrupt this system. Alternatively, those dietary changes could also be behind some of the positive changes reported after a cleanse.

“When you cause significant changes in the intestine, you are at times obliterating many of the beneficial organisms that are helping us digest food, but in some cases, producing vitamins that are actually occupying that niche and preventing bad organisms from taking over,” Lourido said. “All of those different functions … cease to occur correctly when we have diarrhea and we all of sudden make a dramatic change to eating only one kind of food.”

Kurt’s cleanse contained black walnut, cloves and wormwood, along with a handful of other herbs. Most of the cleanse went by without him noticing any changes, but he started to have what he described as “a lot coming out of him in the bathroom” in the last week of it. Then, things took a dark turn.

Extreme anxiety woke him up sweating in the middle of the night. His mental health changed for the worse, and he started to feel numb and anhedonic — things that used to make him happy no longer did. This went on for years. 

“At least a year or two after, I was in really bad shape,” Kurt said. “I was wondering if I was ever going to be the same person that I was prior to doing this cleanse.”

Kurt is not entirely sure whether he had a parasite or not, or how the supplements interacted with his system. But he does think they caused a major shift. He was excreting things he had never seen in his stool before and feeling things he had never felt before. Looking back, he thinks he overdid it and that his body was not ready for the supplements he was taking. To him, it seemed like his reaction was not typical compared to what he had seen others report online.

“At the end of the day, there are a lot of herbs out there and they are very powerful," he said. “I suppose that I will never really get answers as to what really happened because unfortunately, I never really knew what I was dealing with prior to this.”

Supplements are regulated for safety but not efficacy by the 1994 Dietary Supplement Health and Education Act, which is enforced by the U.S. Food and Drug Administration. This agency, along with the Federal Trade Commission, is in charge of monitoring companies to make sure what they're selling on the shelves matches what is being advertised.

Years after Kurt did his cleanse, the FDA sent a warning letter to the company that he bought it from, alleging the company mislabeled its supplements as medical treatments and did not contain enough information about the ingredients.

“The problem with these parasitic cleansers is you don’t really know what is actually going on,” said Dr. Michael Schmidt, a microbiologist and immunologist at the MUSC Medical University of South Carolina. “In general, they come with ‘buyer beware’ attached.”

The rise of the parasite cleanse

Bertollini, the herbalist, said she has seen a “dramatic upswing” in the popularity of these sorts of products in recent years, but that much of it seems to be based on people’s “fear of having parasites.” This fear makes evolutionary sense: Parasites aren't technically predators, but they can cause serious harm as they leech off of their hosts. (On the other hand, some parasites can actually be beneficial — it depends on the species and the relationship with its host.) In one study, raccoons and squirrels would sacrifice food to avoid tick-infested areas, suggesting that they valued the threat of parasites more than the promise of food.

This ancient, justified fear could be the root of delusional parasitosis, a mental health condition in which people have psychological delusions that they have a parasite when they don't really. These folks may be particularly at risk of overconsuming cleansing products, Moore said.

Nevertheless, many people are turning to online treatments for various conditions because of a growing mistrust in the medical system and a lack of access to health care. Although it has a far lower rate of parasitic disease than other countries, the U.S. is the biggest buyer of detox products, including parasite cleanses. At the same time, one Gallup poll estimated that 11% of the population cannot afford or access health care as more people turn to online supplements in an attempt to treat their health problems. 

Take people with conditions that notoriously lack treatments like Crohn’s disease or other inflammatory bowel disorders, which share some common symptoms with intestinal parasite infections. Of the estimated 1 million people in the U.S. with Crohn’s, two-thirds will end up needing surgery because available medications are not enough to keep the progression of the disease at bay. Many may be trying these cleanses in an attempt to feel relief, Moore explained. 

“They’ll try a parasite cleanse not because they are convinced they have a parasite, but because they are reaching for something out of desperation,” he said.

Furthermore, more people might be thinking they are infected with parasites as mistrust also grows surrounding the environmental systems designed to protect our food and ecosystems from dangerous waste. 

Some individuals have gone so far as to stop using the water grid altogether, instead collecting water from natural streams. However, that might ironically increase the risk of drinking water that is contaminated with parasites, if those streams are downriver from waste exposures.

“There is a bit of truth in the sense that the U.S. has been somehow lax in terms of how much processing you allow for food and how much additional ingredients you have,” Chaccour said. “But that is not the same as going out to nature to collect your own water.”

Over time, the symptoms Kurt was experiencing after the cleanse faded away. In 2016, he started going to the gym, and his energy levels returned. His gut stopped bothering him, and he had what he describes as some of the best years of his life. Despite the reaction he had to the cleanse, he does feel that it helped him get there.

“It's hard to say if it was the cleanse that helped me or was it ultimately going to the gym and being a lot more active, or a combination of both.” Kurt said. “Looking back, I could probably say that it was a positive decision.”

However, Kurt has recently entered into another challenging part of his life. He is experiencing a range of new symptoms he thinks stem from an exposure to toxic mold. He has considered doing a parasite cleanse again, even though he doesn't think he has a parasite. On one hand, he feels it helped him 10 years ago and could have a similar effect again.

“But I feel like, if that's not the case, I'm not really in a position to be able to deal with negative effects that might come from it,” he said.

He is burnt out from visiting doctors. In his search for more information on what could be causing his malaise, he finds it difficult to sort through what information online is real and what is bogus, he said. But the anecdotal experiences can only go so far, and what works for one person may not work for another.

“There's a lot of misinformation, but I do think there is a lot of good information out there, and it's just that it comes to a point when it's very difficult to separate which is which,” he said. “It’s certainly a gamble and I think it has its place. You just have to tread with caution.”