About Project SEXUS

Project SEXUS is the world’s most comprehensive individual-based, prospective cohort study with a strict focus on sexuality and its interplay with lifestyle factors and general physical and mental health among 15 to 89-year-old Danes.

First data collection (SEXUS-1) in 2017-2018

The first data collection wave (SEXUS-1) took place between September 2017 and August 2018. Most results presented in the comprehensive 764-page report "Sex in Denmark. Key findings from Project SEXUS 2017-2018" were based on answers provided by a total of 62,675 respondents. The report is in Danish, but it contains a 14-page summary of key findings in English.

Second data collection (SEXUS-2) in 2026

As a prospective cohort study, Project SEXUS will conduct its second data collection wave (SEXUS-2) in 2026, inviting all participants from SEXUS-1 as well as 200,000 other randomly selected Danish citizens aged 15 to 89 years. The first SEXUS-2 results are expected in 2027.

Additional information

• Project SEXUS constitutes a research collaboration between Statens Serum Institut (Department of Infectious Disease Epidemiology and Prevention) and Aalborg University (Center for Sexology Research, Department of Clinical Medicine).
• In the first data collection (SEXUS-1), approximately 200,000 randomly selected Danes aged 15-89 years were invited to participate. We used a comprehensive digital questionnaire covering a broad range of items on sexuality, lifestyles, and health, which took around 30 minutes to complete.
• The SEXUS-1 questionnaire with questions and answers in both Danish and English, comprised approximately 600 items covering a broad range of sexual health and quality-of-life issues such as sexual experiences, current behaviors, orientation, desires, problems, dysfunctions, and attitudes. Due to strategic filter questions, the average respondent answered approximately 180 questions.
• Project SEXUS has received professional recognition from the International Society for Sexual Medicine (Best Paper Prize 2024) and LGBT+ Denmark (Salmon of the Year Prize 2025).
• Beyond its frequent citations in the media and use by public health authorities and decision makers, Project SEXUS has generated multiple scientific publications in peer-reviewed scientific journals, as detailed in the Project SEXUS publication list.
• Project SEXUS has received research grants and funding from several private and public donors.