Mushrooms and a repurposed antidepressant: a new recipe for weight loss?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Men and women aged 18-55 years. * BMI of 25.0 - 34.9 kg/m2. * Signed informed consent. * Have a mobile phone, tablet, or computer with internet access. * Cardiometabolic risk factors: a) None of the following diagnoses: hypertension, hyperlipidemia, or prediabetes according to WHO classification (Stratum A); b) One or several of the following diagnoses: hypertension, hyperlipidemia, or prediabetes according to WHO classification (Stratum B). * For women of childbearing potential: use of a highly effective birth control method Exclusion Criteria: * Present food intolerances and/or allergies of relevance to the interventions, such as celiac disease and allergy to edible mushrooms or fungal spores. * Contraindication to bupropion, or any unacceptable risk with either treatment as assessed by the investigator. Specifically, and not covered elsewhere: 1. History of epilepsy or lowered seizure threshold; 2. History of bulimia or anorexia nervosa; 3. Central nervous system tumor; 4. Hypersensitivity to bupropion; 5. History of bipolar disorder; 6. Known or suspected Brugada syndrome; * Current or recent adherence to a low-calorie diet, receipt of pharmacological treatment for weight loss, and/or weight loss of \> 3 kg within the past 3 months. * Previous or planned bariatric surgery * Diagnosed diabetes, coronary heart disease, heart failure, stroke, liver failure or kidney disease (eGFR\<60 ml/min/1.73m2) as well as other ongoing serious conditions with short life expectancy or conditions affecting participation in the study. * Any condition, as judged by the investigator, that suggests that the participant will be non-compliant or otherwise unsuitable to study medication or study participation. For example, serious psychiatric, eating, alcohol or substance abuse disorders. * Use of the following medications within indicated time frames: 1. Other bupropion-containing products (last 2 weeks); 2. Other weight lowering-drugs: orlistat, phentermine-topiramate, sodium-glucose transporter 2 inhibitors (SGLT2i), GLP-1 receptor agonists (last 3 months); 3. Antipsychotics, mirtazapine, tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors (last 3 months); 4. MAOIs (last 2 weeks); 5. Systemic glucocorticoids (last 3 months); 6. Testosterone, anabolic steroids (last 6 months); 7. Medications not listed above that are metabolized by CYP2D6; 8. Medications that affect CYP2B6; * Be pregnant or intend to become pregnant during the study period. * Involvement in the planning and/or conduct of the study. * Ongoing participation in another interventional clinical trial.