Teresa Castro is a social worker, researcher, activist, peer and person who uses drugs based in Lisboa, Portugal. Involved in harm reduction since the age of 18, she currently collaborates with Kosmicare and is active in several international networks, including IDPC, EATG, Correlation, and R3. Her work focuses on social determinants of health, stimulants and new psychoactive substances, and the meaningful inclusion and leadership of people who use drugs in research, policy, and practice.