Liver cleanse supplements ranked among the bestsellers on Amazon consistently promoted detoxification benefits without corresponding high-quality clinical support, according to a recent study.
Using a cross-sectional design, investigators analyzed Amazon’s 20 top-selling liver cleanse supplements by examining sales estimates, review reliability, ingredient profiles, and published evidence to determine whether the products’ claims aligned with validated liver health data. The investigators found that all evaluated supplements promoted detoxification claims, most achieved high consumer ratings, and their formulations relied largely on ingredients supported by weak or inconclusive clinical data.
Estimated annual sales across the 20 supplements included in the study totaled more than 1.4 million units, corresponding to over $38.8 million in revenue and representing a 12.3% increase compared with 2023 estimates. Average monthly sales were $5,919, with product prices ranging from $18.99 to $39.95. Sales were positively correlated with the products’ age and number of reviews and inversely correlated with price. The mean consumer rating was 4.4 out of 5 stars, while review reliability averaged 73%. Among negative reviews, 62% cited lack of perceived efficacy, and 19% reported adverse effects—most commonly gastrointestinal symptoms.
All of the products claimed to eliminate toxins or provide liver detoxification, and 85% claimed to enhance liver function. Ingredient analysis identified more than 60 compounds, with milk thistle present in 95% n = 19/20) of the products. Just milk thistle, zinc, choline, and berberine demonstrated moderate but mixed clinical evidence, while most ingredients were supported primarily by preclinical or limited human data.
Products were identified using the search terms “liver” and “cleanse” to capture supplements marketed with explicit detoxification claims. To reduce algorithmic and geographic biases, the investigators conducted searches using a newly created Amazon account, private browsing software, ad blockers, and a US-based virtual private network. All product data were archived on the same day to account for the rapidly changing nature of online marketplaces.
Sales volume and revenue estimates were derived using AMZScout, which provided modeled estimates for products with consistent sales histories. Review authenticity was assessed using FakeSpot. Ingredient lists were cataloged, and scientific evidence supporting the most common compounds was evaluated through structured PubMed searches using predefined inclusion criteria. Evidence quality was categorized into four tiers, ranging from high-quality randomized controlled trials to preclinical data. Statistical analyses assessed correlations between sales performance and product characteristics, including price, product age, and review volume.
The investigators noted several limitations. The analysis was limited to a single online retailer and may not have reflected broader market trends. Sales and review metrics were estimated rather than directly reported. In addition, the snapshot design captured data at one time point and may not have accounted for seasonal variation or evolving marketing strategies.
“[O]ur study highlights the need for greater scrutiny of the liver supplement market. Despite generating nearly $40 million in annual revenue, the scientific evidence supporting these supplements remains limited and inconclusive,” stated lead study author Ahmed Telbany, MD, MPH, of the Division of Gastroenterology & Hepatology at the University of New Mexico, and colleagues.
Disclosures can be found in the study.
