Mulberry leaf in a basket.
Mulberry leaf extract is a popular supplement. Penpak Ngamsathain/Getty Images
  • The death of Lori McClintock, wife of congressman Tom McClintock, was ruled a consequence of taking white mulberry leaf extract.
  • Side effects typically include milder gastroenterological symptoms such as nausea and diarrhea. 
  • The severity of McClintock’s reaction was noted as uncommon.

According to recent news reports, Lori McClintock, the wife of a California congressman died late last year from side effects related to the herbal supplement white mulberry leaf extract.

The updated autopsy report and death certificate were obtained by KHN, which broke the news. 

McClintock was the wife of California congressman Tom McClintock and died in late December 2021. According to the KHN report, the coroner found that McClintock’s passing was accidental, the result of severe dehydration caused by acute gastroenteritis — a reaction to taking the extract. Gastroenteritis is an inflammation of the stomach and intestines.

The coroner also noted she complained of experiencing stomach pains the evening before her death. 

KHN reported that a ‘partially intact’ mulberry leaf was discovered in McClintock’s stomach, although it’s unclear how she ingested this. Why she was taking the extract is also unknown — although it’s typically used for diabetes management and aiding weight loss. 

Experiencing such a significant reaction from taking white mulberry leaf extract is uncommon, experts say.

“It’s [also] rare for run-of-the-mill gastroenteritis to cause fatal dehydration,” Dr. Kelly Johnson-Arbor, medical toxicology physician and medical director at the National Capital Poison Center, told Healthline.

Maddie Pasquariello, registered dietitian and founder of Nutrition With Maddie, told Healthline it’s possible that the supplement contained another substance or that McClintock had another undiagnosed condition, which led to the severe symptoms.

What white mulberry leaf extract is used to treat

“White mulberry has been used for thousands of years, as far back as 3000 B.C.,” explained Johnson-Arbor. “It is a tree native to China, Korea, and Japan, [but] is now found across Asia, Europe, and the Americas.”

The plant has long been a popular food source for silkworms and livestock, but it’s also been used in natural medicines for many years.

“White mulberry leaves contain many biologically active compounds, including alkaloids, flavonoids, and antioxidants, that may have beneficial health effects,” said Johnson-Arbor. “When eaten, these compounds can help prevent cell damage, improve glucose levels, and enhance digestion.”

Some modern studies have explored its role in aiding various health conditions. For example, a small UK study found that white mulberry leaf extract may help control diabetes, as consumption led to improved glucose tolerance and decreased insulin concentrations. 

Researchers have also studied if the extract could aid in mitigating the risk of cardiometabolic conditions, such as heart disease and stroke

Meanwhile, research on mice and rats has also indicated the plant could be beneficial in reducing blood pressure, maintaining weight, and enhancing neurological function

But experts including Pasquariello said “more research will be needed to confirm [its potential benefits].”

Does it have any side effects?

“White mulberry leaves and their extracts are generally considered to have minimal toxicity in humans and animals,” explained Johnson-Arbor. 

“This means that mild abdominal discomfort and nausea may occur after consumption,” she continued, “but more severe symptoms [such as those experienced by McClintock] are not expected.”

This sentiment is reflected by research. For example, in a study of 23 patients, a quarter experienced mild diarrhea, while very small percentages had dizziness and constipation or bloating (8.7% and 4.3%, respectively). 

Meanwhile, other research has found similar symptoms and rates among individuals taking white mulberry leaf extract and those consuming placebo solutions. 

For instance, in one study, 62% of participants taking 125mg of white mulberry leaf extract experienced at least one gastrointestinal side effect. However, 57% of the placebo group also reported similar symptoms.

What to know about gastroenteritis

McClintock’s death was ruled an accident arising from dehydration related to acute gastroenteritis.

“Gastroenteritis is an infection of the intestines, most commonly referred to as a ‘stomach virus’, Dr. Casey Kelley, founder and medical director of Case Integrative Health in Chicago, shared with Healthline. 

“Symptoms typically include abdominal discomfort or pain, vomiting, and diarrhea,” she added. “In the majority of cases, gastroenteritis resolves itself in a few days.”

As noted earlier, it is rare for gastroenteritis-related dehydration to lead to death. However, “those with weakened immune systems may struggle [to replace lost fluids],” explained Kelley.  

Natural supplements are extremely popular in the U.S.

Around 80% of American adults take at least one natural supplement, and “many supplements are ‘generally recognized as safe’,” said Pasquariello. 

“From multivitamins and minerals to botanical and herbal ingredients…many can be taken daily with a very low possibility of adverse effects,” she continued.

That said, Kelley explained it’s important to recognize that “not every supplement is for everyone.”

It’s crucial to speak with your primary care doctor before taking a new supplement — especially if you’ve got an existing health condition or are taking medication.

“Many herbal supplements have the potential for dangerous interaction with clinical medications,” shared Pasquariello. 

No FDA regulation

A primary concern regarding natural supplements is that they are not regulated by the Food and Drug Administration (FDA). “The FDA cannot approve them for effectiveness, approve their labels, or ensure they are fully safe,” Pasquariello revealed. 

This lack of regulation also means some “supplements may be contaminated with heavy metals, pesticides, or other potentially dangerous chemicals,” added Johnson-Arbor.

However, just because the FDA isn’t heavily involved “does not mean [supplements] are unsafe to take,” stated Kelley. Instead, “you must take more individual care to discern which supplements are safe and effective.”

As well as checking with your doctor before taking a supplement, Kelley and Pasquariello recommend:

  • Doing your research: Check out the brand or company you’re buying supplements from. Is it reputable, and do they conduct third-party lab analysis and testing on their products?
  • Checking the label: Look for supplements certified by reputable third-party organizations. For instance, “I recommend, NSF International, and US Pharmacopeia (USP),” Kelley shared.
  • Looking for CMGP certification: CMGP is awarded by the FDA following production facility checks. Kelley stated it is the only FDA stamp of approval given in the over-the-counter dietary ingredient space.
  • Listening to your body: If you notice any symptoms (however mild) after taking a supplement, speak to your doctor immediately.


Millions use natural supplements daily to support health and wellbeing, and “integrative medicine and Western medicine can work harmoniously in tandem,” said Kelley. 

However, it’s crucial to recognize that — just like clinical medications — they can cause side effects. Plus, Pasquariello added, “it’s important to keep in mind that supplements are not held to the same standard as clinical medications.”  

White mulberry leaf extract is generally considered safe for human use, with side effects expected to be relatively mild. While the severe reaction experienced by McClintock is uncommon, always check with your doctor before starting a new supplement. 

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