Thomas owns a consultancy business called PlantaPhile® which is based in the US, Germany, and the UK. It focuses on all aspects of herbal product development, registration and licensing.
For the last 22 years, I have developed and managed projects for industry on the use of plants in medicine, food and cosmetics. As a consultant to the Millennium Challenge Corporation, the Centre for Development of Enterprise and the International Trade Centre I have been involved in the preparation, management and execution of various public funded research projects. In 2005 I co-founded the Association of African Medicinal Plants Standards. I currently serve as director of AAMPS and editor-in-chief of the AAMPS African Herbal Pharmacopoeia (2010). I have been author of Herb-CD®, a digital encyclopaedia of medicinal plants, and co-authored, edited and contributed to a wide range of publications on phytotherapy and natural product regulation, most notably "Physician's Desk Reference for Herbal Medicines", "Medicinal and Aromatic Plants of Indian Ocean Islands" and "A Practical Guide To Licensing Herbal Medicinal Products". I am a member of the editorial board of Phytotherapy Research and a regular peer reviewer for Journal of Ethnopharmacology, Ethnobotany Research & Applications, Economic Botany and Herbalgram. I also contributed to the translation into English of the German Commission E monographs on medicinal plants. From 2009-2010 I spent one year as a visiting scholar at Rutgers University (NJ, USA), Department of Plant Biology and Pathology, Natural Product Research Group.