“The people that get usually more ill from things like this are either, one, unlucky—it’s just an unlucky event—or, two, they have some underlying immune dysfunction,” says Dr. Blass.
In 2014, the CDC4 announced five neglected parasitic infections as public health priorities in the U.S.: trichomoniasis, toxoplasmosis, toxocariasis, cysticercosis, and Chagas disease. And while some of these can cause GI symptoms (among other illnesses) they aren’t characterised by worms in your gut.
Toxocariasis, for instance, is an infection that you might be exposed to if your dog has roundworms (which is common in puppies and why deworming your dog is important!), but it wouldn’t cause you to develop the same gnarly roundworm in your own gut. Instead, toxocariasis can lead to an infection in your eyes, liver, or central nervous system, though severe cases are rare.
Toxoplasmosis is another parasite that you can pick up from your pet (particularly your cat’s litter box) or even from eating undercooked meat. In most cases, it doesn’t lead to any symptoms at all, though it’s more serious in pregnant people and those with a weakened immune system.
Giardia and cryptosporidium are two other intestinal parasites that are actually not uncommon in the U.S., both of which are microscopic parasites that wouldn’t cause worms but could cause diarrhea and other GI symptoms, says Dr. Sears.
And then there’s the most common worm infection in the U.S.: pinworm. These little worms typically affect children (or those who care for them), and the most likely symptom is anal itching. But even these common creepy crawlies rarely show up in your poop.
Homeopathic “parasite cleanses” are probably just going to make you poop…a lot. That’s not how parasites are treated.
OK, so if intestinal worms aren’t all that common, how do you explain the dozens of people on TikTok swearing that a “parasite cleanse” had them pooping worms for days? According to Dr. Sears and Dr. Blass, the most likely explanation is that these products are triggering both bowel movements and a heightened attention to what’s in your toilet bowl—both of which could lead to suspicious-looking poops.
“I think they may be seeing mucus threads for example,” says Dr. Sears. “And food as it’s digested can have very odd appearances at times.” This can be especially true when food is partially or incompletely digested.
The products I saw most frequently on TikTok were sold on Amazon and marketed for digestive support. They aren’t claiming to be antiparasitic or antihelminthic, which is good because…they’re not. The ingredients typically included things like wormwood, cloves, and black walnut hull. While wormwood has been researched5 for its possible antiparasitic effects in animals, a recent study6 looking at its efficacy in treating a type of flatworm infection in humans was later retracted. Data on antiparasitic effects of cloves and black walnut hull are similarly lacking.
One explanation is that products like these are “using side effects of natural herbs to cause a laxative—a cathartic—effect,” says Dr. Blass. And, to clarify: “A laxative is not a treatment for a parasitic illness.”