Do Parasite Cleanses Work? We Investigate

We asked a gastrointestinal physician and two naturopaths.

Do Parasite Cleanses Work?

Liz DeSousa for Byrdie

Feeling unwell but can't trace the source? If your symptoms seem to be gut-related—meaning they're affecting your digestive tract as well as your mood and energy—you might come across parasites as a possible explanation.

Parasites are organisms that live off their hosts and can cause serious illness if left untreated, or if treated incorrectly and without medical supervision. According to the Mayo Clinic, parasitic diseases are a serious concern, affecting more than 2 billion people worldwide, usually impoverished populations. However, there are many advances in anti-parasitic therapies and new drugs that can wipe parasitic illnesses out before they become fatal.

We asked a gastrointestinal physician and two naturopaths to break down everything you need to know about contracting parasites and how to get rid of them, as well as their stance on trendy parasite cleanses.

Before we move ahead, a note: The only way to be sure that you have contracted a parasite, or to treat a parasite if you have one, is to schedule an appointment with a gastroenterologist.

Meet the Expert

  • Kate Denniston, ND, is a licensed naturopathic doctor, trained in both conventional and alternative medicine. She specializes in helping women optimize their hormonal health and practices at Los Angeles Integrated Health.
  • Gina Sam, MD, MPH, is a New York City–based gastroenterologist with a niche in gastrointestinal motility disorders. She also specializes in GERD diagnosis and is an expert in IBS.
  • Donese Worden, NMD, is a naturopathic medical doctor and expert diagnostician. She specializes in integrative medicine.

What Is a Parasite?

A parasite is an organism living in, or on, a host organism in order to obtain nutrients, grow, or multiply. This often indirectly harms the host. 

Types of Parasites

According to the Centers for Disease Control, there are three main classifications of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites.

  • Protozoa: Protozoa are single-celled organisms that can only multiply within the host. You can't see them without a microscope, but they can move about on their own. Two common types of disease-causing protozoa are Giardia and Amoeba. Giardia mainly affects the small intestines and are transmitted through contaminated food, water, or feces. Amoeba is another common protozoa parasite, also transmitted through contaminated food, water, feces, or soil. Amoeba reproduce via larvae, called cysts. Different species of amoeba can affect us differently, causing infection in the intestines, the eyes, the skin, and in some cases, the brain.
  • Helminths or Worms: Helminths are also known as parasitic worms, which may or may not be visible to the human eye. Flatworms, which include tapeworms are one of the most common types of parasitic worms. You get these by drinking water contaminated with tapeworm eggs or larvae, or by ingesting raw or undercooked meat. Tapeworms usually are localized in the intestines, where they burrow. Their mature eggs hatch into larvae that can travel throughout the body. Roundworms are another very common parasitic worm, also called nematodes. You can get roundworms from eating the meat of an infected animal or undercooked meat that contains roundworm larvae. Some roundworms can lodge in the colon and rectum.
  • Ectoparasites: Ectoparasites are parasites that live externally on the hosts, as opposed to inside. They commonly lodge onto skin and hair. Examples are lice and fleas.

How You Contract Parasites

Poor hygiene and poor sanitation, including contaminated water, food, and soil are ways people can contract parasites. Worden notes that contraction is "more likely with international travel." She adds that the "elderly and young children are more likely to get infected."

According to Sam, another parasitic source is contaminated food: Bad sushi, bad fish, or bad pork can cause parasites. She notes that all kinds of contact with contaminated water can pose a parasitic risk. "If you go swimming in contaminated water, some parasites can enter through the skin," says Sam.

Intestinal parasites can be more serious if you are pregnant. A doctor can tell you which drugs are safe to take during pregnancy.

Symptoms and Diagnosis

The tricky thing about symptoms of a parasite, is that they're vague and non-specific. Denniston says they can include "gastrointestinal symptoms, fatigue, anemia, weight loss, nutrient deficiencies, rashes, and itchiness."

Sam says that at the first sign of diarrhea, you should call your physician, especially if you've been traveling.

Worden says the Scotch tape test might be effective in identifying pinworms. To perform, "touch tape to the anus several times, then look at the tape for eggs. Mothers for centuries have done this test on their children, but it’s not as accurate as the newer tests we have now."

According to Worden, there are no FDA-approved full parasite home kits on the market. "There are several professional companies and labs that physicians use," she explains. "I studied several years with a world-renowned parasitologist, and I learned early on that many pathogens are missed by poor labs and analysis." In her practice, she analyzes stool samples with MicroGen, "which uses a PCR analysis. This allows a more in-depth look at bacteria, fungi, viruses, and parasites."  

Are Parasite Cleanses Effective?

There are different types of parasite cleanses on the market, positioned as natural ways to detox the system. Usually their formulas contain herbs and supplements. According to Worden, the following are some of the herbs and plant medicinals that might be included in a parasite cleanse.

·       Garlic (Allium sativum)

·       Barberry (Berberis vulgaris)

·       Goldenseal (Hydrastis canadensis)

·       Oregon grape (Berberis aquifolium)

·       Anise (Pimpinella anisum)

·       Wormwood (Artemisia annua)

·       Curled mint (Mentha crispa)

·       Black walnuts (Juglans nigra)

Worden notes, "Many of the herbs used to treat intestinal parasites have toxic side effects or interfere with other medications," underscoring that in order for herbal tinctures to be effective, a physician must diagnose what kind of parasite you have.

Denniston adds, "Typically these cleanses use anti-parasitic herbs that have compounds that kill off parasites. A lot of these herbs, like wormwood, have been used for thousands of years to kill parasites." She does not advocate using a parasite cleanse without the supervision of your doctor.

Finally, Denniston says that "it's important to make sure you are in a healthy state and that you have all your pathways of elimination working well before cleansing. It's not a good idea to do any kind of cleanse if you're not having regular bowel movements before you start."

Sam says emphatically that the only time a person should use a parasite cleanse is after he or she has eliminated the parasite with anti-parasitic drugs. "If you have a parasite, you kill it. If it’s still there, kill it again," she says. "Only after you've cleaned out your tract and have re-tested [for parasites] and the stool is clear" should you embark on a parasite cleanse. "Go back to science. You have to start with functional medicine," says Sam. She says a parasite cleanse can help "restart the GI tract" and can be good for overall wellness, but that the only effective remedy against parasites is prescription medication that's species-specific.

Preventing Parasites

People traveling outside the United States or to areas with contaminated water sources are at risk for developing parasites. "When you travel, be aware of what type of water you come in contact with and where your water is coming from," says Sam. She also advises that you travel with a water filtering system, such as Brita, or boil the tap water.

Some people might be more susceptible to getting parasites, including, according to Denniston, people with weakened immune systems. "Persistent stress, poor sleep, nutrient deficiencies, and imbalances in the gut microbiome can negatively impact our immune system" Denniston says,

Worden agrees, adding that "gastrointestinal health is key as it correlates with the immune system. In other words, bad gut, bad immune system, which makes it easy for infections and parasites to populate. I tell my patients that if they inadvertently expose their GI tract (swallowing eggs or parasites themselves), the bugs will choose to stay and replicate according to their gut health." 

The Final Takeaway

The sole way to properly treat a parasite is proper diagnosis and medical treatment. Our experts all agree: You must visit your doctor or a gastrointestinal specialist and have your stool tested. "Diagnosing the correct agency will determine the course of anti-parasitic [drugs]," explains Sam. "There are subtypes and subspecies, so it's very important to get a proper diagnosis from a lab."

Some anti-parasitic courses work in as little as seven to 10 days. "Others are more resistant and might require more treatment," Sam says. Testing, she explains, is the only way to know for sure if you're clear. "Call me," she says. "I will spend hours analyzing your stool."

Article Sources
Byrdie takes every opportunity to use high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial guidelines to learn more about how we keep our content accurate, reliable and trustworthy.
  1. Centers for Disease Control and Prevention. About Parasites. Updated September 18, 2020.

  2. Burgess SL, Gilchrist CA, Lynn TC, Petri WA Jr. Parasitic Protozoa and Interactions With the Host Intestinal Microbiota. Infect Immun. 2017;85(8):e00101-17. doi:10.1128/IAI.00101-17

  3. Idris OA, Wintola OA, Afolayan AJ. Helminthiases; Prevalence, Transmission, Host-parasite Interactions, Resistance to Common Synthetic Drugs and Treatment. Heliyon. 2019;5(1):e01161. doi:10.1016/j.heliyon.2019.e01161

  4. Kupfer TR, Fessler DMT. Ectoparasite Defence in Humans: Relationships to Pathogen Avoidance and Clinical Implications. Philos Trans R Soc Lond B Biol Sci. 2018;373(1751):20170207. doi:10.1098/rstb.2017.0207

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