An observational study in Sexual Desire, sponsored by University Hospital, Basel, Switzerland. Completed at 1 site in Switzerland. Open to participants aged 18 Years to 75 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-12-23.
Sponsored by University Hospital, Basel, Switzerland · Observational
This study is to investigate the effects of GLP-1 analogues (combined with lifestyle interventions in comparison to lifestyle interventions only) on sexual desire, mood, quality of life, the reproductive axis, retinal vessel diameters, physical fitness (and semen, for men only) in overweight or obese men and women.
Glucagon-like peptide-1 (GLP-1) analogues are widely used for the treatment of type 2 diabetes mellitus due to its well-known insulinotropic effects as well as for the treatment of obesity due to its satiation-promoting and appetite- suppressant effects. The GLP-1 analogues are approved in patients with obesity (BMI ≥ 30 kg/m2) or who are overweight (BMI ≥ 27 kg/m2) with additional comorbidities, such as prediabetes, diabetes mellitus type 2, arterial hypertension or dyslipidemia. Beside its influence on the reward for palatable food, several studies have shown that GLP-1 analogues modulate the rewarding effects of addictive drugs such as alcohol, nicotine and cocaine. As a further natural reward, sexual desire could be affected by GLP-1 analogues likewise.
This study investigates the influence of GLP-1 analogues on sexuality in a population of overweight and obese participants. A treatment with a GLP-1 analogue combined with lifestyle modifications for weight reduction will be compared to weight reduction with conventional lifestyle modifications only. In the context of the increasing use of GLP-1 analogues, particularly in young people with reproductive desire, laboratory analyzes of the reproductive axis (hormones and sperm cells) will be part of this study to document a possible influence. Mood changes, physical activity and fitness and effects on microvascular endothelial functioning by measuring diameters of retinal vessels will be further investigated.
11,522 studies on the registry are indexed under Obesity; 2,033 are open to participants now.
This study's enrollment of 85 is below the median of 114 across 2,154 observational studies indexed under Obesity.
Browse Obesity studies →University Hospital, Basel, Switzerland is the lead sponsor of 990 studies on the registry; 189 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The study population will consist of overweight men and women (BMI ≥ 27 kg/m2), which are seen at the obesity clinic of the University Hospital Basel and who wish to lose weight by lifestyle changes and optionally in combination with liraglutide treatment.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Eugonadism:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GLP-1 Group: receiving GLP-1 analogues for weight management in addition to conventional weight management (= lifestyle intervention plus GLP-1 analogues). Conventional weight management is conducted according to clinical guidelines (in both groups) and includes nutritional and exercise counselling, counselling by motivational coaches and/ or psychological support. Participants in the GLP-1 group will inject the medication themselves.
Lifestyle group: using conventional weight management (= lifestyle intervention only). Conventional weight management is conducted according to clinical guidelines (in both groups) and includes nutritional and exercise counselling, counselling by motivational coaches and/ or psychological support.
Change in the German short version of the Sexual Desire Inventory (SDI-2) total score to assess sexual functioning
The SDI-2 consists of two items addressing frequency of sexual thoughts or activity, rated by a discrete score ranging from 0 to 7 (0 = not at all; 1 = once a month; 2 = once in two weeks; 3 = once a week; 4 = twice a week; 5 = three to four times a week; 6 = once a day; 7 = several times a day), and eight items rating the strengths of different types of sexual desires, rated by a continuous score ranging from 0 to 8 (0 = no desire to 8 = strong desire). The SDI-2 sum score ranges from 0 to 78. A positive score change indicates improvement of sexual desire.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in the International Index of Erectile Function (IIEF-5) for men or Female Sexual Function Index (FSFI) for women questionnaire to assess sexual health and erectile function
The IIEF-5 is a 15-item self-evaluation scale; it provides pre-post treatment clinic evaluations of erectile function, orgasmic function, sexual desire, satisfaction in sexual intercourse and general satisfaction. The FSFI is a 19-item self-reporting questionnaire; it measures dimensions such as desire, arousal, lubrication, orgasm, satisfaction, and pain during sexual activity.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in the Patient Health Questionnaire (PHQ) -9 questionnaire to assess mood changes
The PHQ-9 tool may reflect patients' accounts of their experiences of depression and to assess severity of and treatment response. Each of the 9 items can be scored from 0 (not at all) to 3 (nearly every day).
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in the Patient Health Questionnaire (EQ-5D-5L) questionnaire to assess quality of life
The EQ-5D descriptive system comprises five dimensions: mobility, self-care, usual activities, pain and discomfort, and anxiety and depression. The five levels in each dimension are worded as (1) 'not /no problems', (2) 'slight problems', (3) 'moderate problems', (4) 'severe problems', and (5) 'unable to' (mobility, self-care, usual activities), 'extreme' (pain/depression), or 'extremely' (anxiety/depression). The second part of the questionnaire comprises a standard vertical 20-cm VAS that is calibrated from 'the worst health you can imagine' (scored 0) at its base to 'the best health you can imagine' (scored 100) at its apex.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in retinal vessel diameters to assess microvascular endothelial functioning
Change in retinal vessel diameters with the Static Retinal Vessel Analyzer (SVA-T, Imedos Systems UG, Jena, Germany). The system consists of a fundus camera (Topcon TRC NW8) and analyzing software (Visualis 3.2, Imedos Systems UG), allowing non-invasive and non-mydriatic assessment of retinal vessel diameters.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in Oxytocin Level (IU) (hormone of the reproductive axis)
Oxytocin Level (hormone of the reproductive axis) will be measured in the blood.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in semen concentration
Change in semen concentration
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in peak oxygen consumption during spiroergometry to assess physical fitness
Change in peak oxygen consumption during spiroergometry
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in maximum heart rate during spiroergometry
Change in maximum heart rate during spiroergometry
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in the Freiburg questionnaire for physical activity (FQPA)
The questionnaire consists of 12 items and allows a calculation of weighted metabolic equivalent tasks (MET) hours per week. The Physical Activity Questionnaire (FPAQ) is used to measure physical activity. Individuals are considered physically active when they achieved metabolic equivalent tasks (MET) minutes of 600 or more per week.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in Testosterone level (nmol/l) (hormone of the reproductive axis)
Testosterone level (hormone of the reproductive axis) will be measured in the blood.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in Estradiol level (pmol/l) (hormone of the reproductive axis)
Estradiol level (hormone of the reproductive axis) will be measured in the blood.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in Sex hormone-binding globulin (SHBG) level (nmol/l) (hormone of the reproductive axis)
Sex hormone-binding globulin (SHBG) level (hormone of the reproductive axis) will be measured in the blood.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in Luteinising hormone (LH) level (U/l) (hormone of the reproductive axis)
Luteinising hormone (LH) level (hormone of the reproductive axis) will be measured in the blood.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in Follicle stimulating hormone (LH) level (U/l) (hormone of the reproductive axis)
Follicle stimulating hormone level (hormone of the reproductive axis) will be measured in the blood.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in Prolactin level (yg/l) (hormone of the reproductive axis)
Prolactin level (hormone of the reproductive axis) will be measured in the blood immediately (10-20 min) after ejaculation.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in semen motility
Change in semen motility
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in sperm fragmentation index (percentage of sperm with fragmented DNA)
Change in sperm fragmentation index (percentage of sperm with fragmented DNA)
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in body weight (kg)
Body weight is measured during the bioelectrical impedance analysis. The "InBody 720" device is used to perform the analysis.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in body fat mass (%)
Body fat mass is measured during the bioelectrical impedance analysis. The "InBody 720" device is used to perform the analysis.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in total body water (l)
Total body water is measured during the bioelectrical impedance analysis. The "InBody 720" device is used to perform the analysis.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in extracellular water (%)
Extracellular water is measured during the bioelectrical impedance analysis. The "InBody 720" device is used to perform the analysis.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in intracellular water (%)
Intracellular water is measured during the bioelectrical impedance analysis. The "InBody 720" device is used to perform the analysis.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in hip/waist ratio
Hip/waist ratio is measured during the bioelectrical impedance analysis. The "InBody 720" device is used to perform the analysis.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in Basal metabolic rate ((kcal/24h)
Basal metabolic rate is measured during the bioelectrical impedance analysis. The "InBody 720" device is used to perform the analysis.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
Change in visceral fat (%)
Visceral fat is measured during the bioelectrical impedance analysis. The "InBody 720" device is used to perform the analysis.
Time frame: At baseline (before start of treatment, at V1) and after 4-6 months of treatment (V2)
This study is completed, as verified in Dec 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University Hospital, Basel, Switzerland →