Quality assessment of Andrographis paniculata products reveals significant labelling inaccuracies and contaminations

BACKGROUND: Andrographis paniculata products have gained in popularity for the management of respiratory infections since the COVID-19 pandemic. None of these products holds marketing authorisation and all are sold as herbal food supplements. Current herbal food supplement regulations generally do not impose quality assessments prior to commercialisation, such that the quality of herbal food supplements available to consumers is largely unknown. STUDY AIM: To assess the quality, purity and labelling accuracy of A. paniculata-containing products, focusing on andrographolide content (the pharmaceutically active component) and the presence of contaminants and residues. METHODS: Forty A. paniculata-containing products were purchased from 13 countries: 13 from pharmacies and 27 from online retailers readily accessible to consumers in Switzerland. Samples were analysed using ultra-high-performance liquid chromatography-ultraviolet (UHPLC-UV) and ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) based on the European Pharmacopoeia method. Contaminants and residues were assessed using inductively coupled plasma mass spectrometry and gas chromatography-mass spectrometry, respectively. RESULTS: All samples except one contained A. paniculata. The measured daily dose of andrographolide was compared to the labelled dose. Andrographolide content ranged from 29% to 174% of the labelled dose, with only 2 products accurately labelled, while 20 were underdosed and 1 overdosed. Two products contained quercetin, which interfered with UHPLC-UV analysis. Additionally, three online-purchased products contained toxic contaminants, including a heavy metal (mercury) or pesticides (strychnine, butralin). CONCLUSION: This study reveals widespread mislabelling and underdosing in A. paniculata-containing food supplements marketed internationally, along with the presence of impurities that pose risks to consumers in products bought online. Regulatory authorities must implement stringent quality controls to ensure consumer safety and product transparency.