The 10 best-selling liver health supplements on Amazon bring in an estimated $2.5 million each month, although none of them contain ingredients recommended by physicians who treat liver issues in the United States or Europe.
Like many supplements, popular online liver supplements are unregulated by the U.S. Food and Drug Administration (FDA), meaning they do not have to meet the same safety and effectiveness standards as prescription medications.
Sales of liver supplements are growing, particularly in the last few years, said Ahmed Eltelbany, MD, MPH, a first-year gastrointestinal fellow at the University of New Mexico. One reason could be increased alcohol use during the COVID-19 pandemic, he said.
Some manufacturers make bold claims on Amazon, said Eltelbany, author of a study that looked into the supplements. "The most recurrent claims were that their supplements maintain normal liver function, are scientifically formulated, and – my personal favorite – are a highly effective liver detox formulation developed according to the latest scientific findings."
Many supplements are marketed as "liver cleansing," for "liver detox," or for "liver support." While these claims might sound reassuring and scientifically grounded to an average consumer, he said, most of them are not backed up by rigorous clinical research.
Does Natural Mean Safe?
"People take these supplements because they believe they're natural and therefore they're safe," said Paul Y. Kwo, MD, who moderated a session on this study at the American College of Gastroenterology conference.
When asked to comment, "As I tell every patient in (my) clinic, a great white shark is natural, a scorpion is natural, and so is a hurricane. So just because they're natural doesn't mean they're safe." At the same time, "It's not that every supplement is bad for you. Nonetheless, there's just a dizzying array of these out there." said Kwo, a professor of medicine at Stanford Medicine in Redwood, CA.
"We have to be very cautious," he said. For example, some people might believe that "if a little bit of a supplement is good, a tremendous amount must be really good." The antioxidant turmeric, for example, has a pretty good safety record, he said. But this past year, some liver toxicity concerns arose about preparations with "very, very high concentrations" of turmeric.
hat tip to Medscape