This study is a single-arm feasibility trial evaluating a 10-week web-based psychoeducational intervention for women with functional hypothalamic amenorrhea (FHA). The primary aim is to assess feasibility and acceptability prior to a future randomized controlled trial.

Intervention The intervention is delivered via a secure web-based platform over 10 weeks. It consists of sequentially released modules including psychoeducational content, reflective exercises, and practical strategies targeting factors relevant to FHA, including energy availability, stress regulation, recovery, nutrition, physical activity, and psychological well-being. The program is self-guided and designed for remote access. No therapist support is provided within the platform.

The intervention content has been developed through an iterative co-creation process involving clinicians (gynecology, psychology, physiotherapy, dietetics) and patient representatives.

Study procedures and setting Participants are recruited via self-referral or clinical referral from gynecological outpatient services. All participants undergo baseline clinical assessment at the Gynecological Endocrinology Clinic at Karolinska University Hospital to confirm diagnosis of FHA prior to enrollment.

Assessments are conducted at baseline (T0), post-intervention at 10 weeks (T1), and follow-up at 4 weeks post-intervention (T2).

At baseline, diagnosis is confirmed through clinical evaluation, medical history, gynecological examination, and hormonal assessment consistent with hypogonadotropic hypogonadism. Psychiatric comorbidity is assessed using the Mini-International Neuropsychiatric Interview (MINI).

Self-report questionnaires are completed electronically via REDCap at T0 and T1, assessing psychological and behavioral outcomes including perceived stress, coping, anxiety, depressive symptoms, eating-related behaviors, exercise patterns, and personality-related traits associated with FHA.

Outcomes Primary outcomes include feasibility and acceptability metrics: recruitment rate, retention, intervention completion, adherence to modules, and participant satisfaction.

Secondary outcome includes change in luteinizing hormone (LH) levels from baseline to post-intervention as a physiological marker of hypothalamic-pituitary-gonadal axis activity.

Exploratory outcomes include changes in psychological and behavioral measures from baseline to post-intervention and follow-up.

Statistical analysis Descriptive statistics will be used to summarize feasibility outcomes. Changes in continuous outcomes will be analyzed using paired t-tests or Wilcoxon signed-rank tests as appropriate. Missing data will be handled using multiple imputation. Analyses will be conducted using IBM SPSS Statistics.

Ethical considerations Participants not meeting eligibility criteria or requiring additional clinical care will be referred to appropriate healthcare services. The study is conducted in accordance with applicable ethical guidelines for human research.

Inclusion Criteria:

Female participants aged 18-40 years Clinical diagnosis of functional hypothalamic amenorrhea (hypogonadotropic hypogonadism) confirmed by clinical assessment Ability to understand and read Swedish Access to a computer and internet connection Willing and able to provide informed consent

Exclusion Criteria:

Current or past diagnosis of anorexia nervosa Severe psychiatric comorbidity (e.g., psychotic disorders) that may interfere with study participation Inability to understand or read Swedish Medical or gynecological conditions other than FHA that explain amenorrhea