Testing at a lab in Oregon revealed that nine out of 10 products labeled as Tejocote Root were actually a plant called yellow oleander that is toxic to humans, according to findings published Thursday in the Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report. Tejocote Root is a weight loss supplement widely regarded as bogus by experts that is nonetheless commonly found on pharmacy shelves and sold by popular online retailers.

It’s likely “just the tip of the iceberg,” said Noah Berland, an emergency physician and medical toxicologist in New York. Berland and his team asked the Oregon lab to test products after a two-year-old was hospitalized last year with nausea, vomiting and heart palpitations from consuming a product labeled as Tejocote Root that was bought online by the child’s mother. 

“Nobody should be buying anything for weight loss over-the-counter,” Berland said.

Since last year, he’s connected with colleagues in several different states who have reported similar cases of hospitalizations from weight loss supplements, including a 16 year old in Illinois and a 63 year old in Minnesota. Berland and the Oregon lab have also tested other weight loss products sold online, and have found the same toxic plant. 

The diet industry has long peddled unproven pills, supplements and foods to Americans looking for a quick way to shed pounds. Research has shown that one in five women and one in 10 men report using weight loss supplements. Americans spend about $2.1 billion a year on weight loss supplements in pill form.

Now, highly effective and safe weight loss medications exist for those who are able to get a prescription. This has led to new interest in bogus weight loss treatments, too, as Americans who can’t get their hands on the real deal buy cheap, unregulated alternatives. Those include berberine — a supplement touted as “Nature’s Ozempic” — and knock-off versions of Novo Nordisk A/S and Eli Lilly & Co’s drugs.

When ingested, yellow oleander can cause severe neurological, gastrointestinal and cardiovascular effects. It doesn’t take much for the poison to kick in. The two-year-old child only ingested one piece of the Tejocote Root, according to the mother, although doctors weren’t able to confirm that. “Any exposure is potentially life-threatening and dangerous,” Berland said.

Separately, the Food and Drug Administration recently warned consumers about weight loss products and botanical foods labeled as “Nuez de la India,” or candlenuts, which were also found to be yellow oleander. The FDA said at least one person in Maryland was hospitalized from eating Nut Diet Max seeds, sold through retailers including Walmart Inc and eBay Inc. Neither company responded immediately to a request for comment. The FDA said it’s working with third-party platforms where the products are sold. 

Doctors in Texas published a case report of another young patient who was hospitalized and later experienced serious cardiovascular symptoms after eating candlenuts for weight loss. They wrote that her symptoms were consistent with toxicity seen from yellow oleander. 

Berland said he hasn’t figured out why the toxic plant is being misbranded as a weight loss supplement. There is no evidence it actually helps with weight loss, he said.

An online search for Tejocote Root shows dozens of different products still available for consumers to purchase from most popular online retailers. The social media app TikTok, which has fueled interest in Ozempic and Wegovy, is also flooded with videos touting the unproven weight loss benefits of taking Tejocote Root. Some products, including one that tested positive for yellow oleander, are available to purchase directly on the app. TikTok did not immediately respond to request for comment.