Supplementary Material of the "Melatonin as a possible stimulus to unmask an oxytocin deficient state in hypopituitarism and hypothalamic damage" trial (NCT05319301), that includes: - Supplementary Appendix 1. Main exclusion criteria. - Supplementary Appendix 2. Questionnaires and interpretation. - Supplementary Table 1. Correlations (rho spearman) between questionnaire scores and OXT parameters (i.e. fasting OXT and OXT AUC and mean percentage change in OXT from T0 to T90 in response to melatonin) among study groups.