Henrik Thiesen specialised as a family physician in 1998 and community doctor in the year 2000.

He is a Consultant in addiction medicine, and co-initiator of a larger in-patient facility for drug and alcohol use since 1996.

Between 2000-2005 he was manager of a street-outreach project combining medical and social staff and since 2005 manager and physician of the in HealthTeam for Homeless, Copenhagen, which addresses gaps in treatment possibilities for homeless people in Copenhagen in the framework of a “family practice without walls”, treating people wherever they are, initiating and maintaining treatment for trimorbid conditions (somatic, psychiatric and drug-related) until a stable connection with the main-stream health-system can be achieved. Since 2008 Henrik has been medical manager of a low threshold out-patient clinic in central Copenhagen.

Since 2013 he has been a medical manager of safe injection room and outpatient shelter-clinics and manager of an Overdose prevention project using naloxone as a nasal spray.