Quality of food supplements vs. registered herbal drug products from passionflower (Passiflora incarnata)

The aerial parts of Passiflora incarnata are used to relieve symptoms of mental stress and promote sleep [ 1 ]. In Europe, passion flower products are marketed either as registered herbal medicinal products or as food supplements. However, consumers often struggle to distinguish between these categories. This study analyzed the quality of various passion flower food supplements and registered drug products using validated analytical methods. TLC fingerprinting revealed that five food supplements did not meet specifications, while six products complied (five of which were registered medicinal products). A validated UHPLC method confirmed these findings. LC-MS analysis showed that one food supplement contained only hyperoside, lacking other passion flower-related compounds. Quantitative flavone analysis using photometric and UHPLC methods indicated that five out of six food supplements failed to meet content and identity requirements, suggesting cases of food fraud. In contrast, all registered herbal drug products complied with specifications. As part of the evaluation, product authenticity as Passiflora -based supplements was verified and declared flavone contents per unit dose were compared with analytical results to assess labeling compliance [ 2 ]. Since the findings align with previous reports on the poor quality of food supplements containing botanicals, increased transparency and stricter quality control measures are recommended. Additionally, manufacturers should conduct routine batch-by-batch analyses, using validated procedures to ensure consistent product quality and consumer safety. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany