The aim of this prospective longitudinal study is to investigate the risks associated with use of anabolic steroids in fitness circles in Denmark in order to assess the scope of therapeutic need existing as a consequence of use. The objectives are:

• To assess long-term complications and outcomes related to: cardiovascular disease, diabetes, gonadal disease (women and men) and psychiatric disease using data from Danish registries including addressing central questions such as whether the following characteristics play a role for development of overt disease
• Characterization of illicit AAS use among men and women
• Current male reproductive health
• Current psychological well-being, aggressive tendencies, cognitive function and quality of life
• Current cardiovascular and metabolic status

The participants will undergo:

• Semi-structured medical interview
• Physical examinations
• Questionnaires
• Blood and urine sampling
• Dual X-ray Absorptiometry

With a subset undergoing further testing, including semen analysis, gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropinm (hCG) stimulation and 82Rubidium positron emission tomography and computer tomography (PET/CT).

Register-based follow-up is planned every third year until the 15th year, marking the completion of the trial.

The study will include 800 participants with current or former AAS use and 100 participants (80 male; 20 female) as controls with no former or current use of AAS.

Anabolic steroids (AAS) are synthetic derivates of the male sexhormone testosterone. The use of AAS is a growing phenomenon and have extended beyond the elite performance and body builder communities, involving a broader populace. The continued use causes a long-term impairment of testicular function, with symptoms of including impotence, depression, infertility and an increased risk of cardiovascular disease. AAS use is a clinical challenge as many psychological symptoms worsen in case of cessation of use. As AAS is often used by young individuals, the fulminant disease is rarely found by incidental screening. To assess long-term consequences, a large cohort is in need to be studied to accurately identify the risk of disease and when to initiate treatment. Furthermore, despite the use of AAS in women is present, the scientific community has thus far not taken notice, and the consequences are unknown, but are presumed to - beyond the changes in physical appearance - to include changes in fertility, risk of type 2 diabetes and cardiovascular disease. As AAS is acquired illicitly, the knowledge on the consequences of AAS use is sparse. No international or national consensus or recommendations exist as to the how to stop AAS use, screening of disease or therapeutic option in case of manifestations of symptoms or fulminant disease. The aim of the current study is to elucidate on the consequences of use of AAS in fitness circles in Denmark to assess the scope of therapeutic need.

Inclusion Criteria:

- Male and female recreational athletes (≥18 years of age) with current or former illicit use (>3 months since AAS cessation) of PIEDs (e.g. AAS) for a minimum four weeks

Inclusion Criteria (Controls, n = 100):

- Male (n=80) or female (n=20) recreational athletes (≥18 years of age) with NO current or former illicit use of AAS.

Exclusion Criteria:

• Severe psychiatric or somatic diseases which makes it impossible to give informed consent or comply with the investigatory program.
• Known pregnancy.

Participants with current or former use of anabolic steroids of both male and female sex. The study also includes a control group (n=100 [male/female] - 80/20)

Due to national judicial restrictions individual participant data cannot be shared.