Pierre Chappard was the chairman of Act Up-Paris from 2009 to 2011. Formerly the coordinator of the French Harm Reduction Network, he is currently the chairman of PsychoACTIF, an online platform created in 2006 as an internet forum. The goal of PsychoACTIF is twofold: on a practical level, it aims at helping people who use drugs through sharing experiences and providing scientific studies ; on a political level, it builds on the hundreds of thousands of stories gathered on the forum to change public policies and working practices in the field of addiction. With Jean-Pierre Couteron, he co-authored Salle de shoot – Les salles d’injection supervisée à l’heure du débat français (2013).
