It was the reporting of 23 such events that led to Hydroxycut maker, Iovate Health Sciences Research, withdrawing the product in May last year before reintroducing it some months later with a revised formulation.
The researchers found Hydroxycut was linked to acute liver failure and death after 17 cases were analyzed directly or indirectly by the researchers led by Tse-Ling Fong of the University of California in Los Angeles.
Of the eight cases looked at by Fong’s team it was deemed 95 per cent likely that the supplements that sold nine million units in 2008 were to blame for the liver toxicity problems.
Typical symptoms included jaundice, fatigue, nausea, vomiting and abdominal pain.
The researchers considered patients' risk factors for liver disease and the timing of their Hydroxycut in their analysis.
Of the 17 cases they analyzed, three needed liver transplants and one died.
The reformulated version called Thermogenic Hydroxycut Advanced contains blueberry extracts, vitamin C and other antioxidants, along with caffeine. Only caffeine remains from the initial version.
The specific ingredient that caused the problem has not yet been identified by the FDA, despite testing.
Australia’s Therapeutic Goods Administration (TGA) recently launched a review of the supplement, which is available in yet another formulation, after a man was hospitalized with acute hepatitis.
The man said he had not exceeded recommended dosages and had consumed the supplement for 10 weeks before the symptoms kicked in. He was hospitalized for eight days but made a full recovery.
Privately-owned Iovate distributes hundreds of weight loss and muscle-building products and is present in more than 60 countries.
After the recall in May, Iovate was to review the ingredients but there has been no publication of these findings, although the company said in a web posting that third-party experts, “review the safety of Iovate’s ingredients and formulas before products are introduced in the marketplace.”
The company is also facing several lawsuits mounted by some of those claiming liver, muscle and other problems from using the products.
Ingredients currently used in weight loss supplements include bitter orange, chromium, guar gum, hoodia, garcinia, conjugated linoleic acid (CLA), pyruvate and chitosan.
Source: American Journal of Gastroenterology
Hepatotoxicity Due to Hydroxycut: A Case Series
Advance online publication, 26 January 2010; doi:10.1038/ajg.2010.
Authors: Tse-Ling Fong, Karl C Klontz , Alejandro Canas-Coto , Steven J Casper , Francisco A Durazo , Timothy J Davern , Paul Hayashi , William M Lee and Leonard B Seeff.