Evaluating product demographics, composition and health claims of commercial polyphenol supplements: a review of dosage, bioactive compounds and efficacy

Abstract

This study evaluated the product demographics of commercial polyphenol supplements, including the identities of polyphenolic compounds, recommended daily dosages and claimed health benefits. Only oral supplement products that specified their polyphenol compositions on their labels were included. Data were collected from three major pharmaceutical retail outlets (Guardians, Watson, Unity) and two e-commerce platforms (iHerbs, Amazon). Trained personnel documented product delivery forms, polyphenol compositions, health claims, and dosages. A total of 196 products met the inclusion criteria, predominantly delivered as capsules (79.3%), followed by tablets (9.3%), soft gels (6.2%), liquids (3.1%), and powders (1.0%). Nearly half (49.5%) declared health claims, categorized into 16 domains. Weight management claims were the most common (33%), followed by antioxidant (25%), cardiovascular, and immunity-related claims. Digestion, hormonal, joint, respiratory, skin, and stress-related claims were least frequent. Epigallocatechin gallate was the most often listed polyphenol, followed by catechins, quercetin, and trans-resveratrol. Recommended daily doses of these compounds (5 mg – 1260 mg) significantly exceeded typical dietary intakes from fruits and vegetables. While polyphenol supplementation shows promise for enhancing health, the lack of statistically significant dosage variation and long-term clinical data underscores the need for further research to confirm efficacy, safety, and best dosing strategies for diverse populations.