This study evaluates the impact of intranasal oxytocin vs placebo in patients with binge eating disorder or episodes of binging. We hypothesize that 8 weeks of intranasal oxytocin vs placebo will improve clinical outcomes [reduction in bingeing frequency], and have a satisfactory safety and tolerability profile. We will also explore the predictive value of changes in homeostatic appetite, reward sensitivity, and impulse control, the identified underlying mediators, as assessed 4 weeks into the intervention, for treatment success after 8 weeks of the intervention.

Study staff will screen patients for eligibility as per eligibility criteria. At least 60 eligible patients will be randomized 1:1 (active oxytocin: placebo) by an unblinded pharmacist. All other study staff and test subjects will be blinded. Study subject medical histories, physical exams, anthropometric measurements, labs, EKG's, and eating habits will be monitored over 8 weeks. Subjects will be evaluated at the following intervals: Baseline, week 2, week 4, week 8, and week 16 (8 weeks post-treatment).

Inclusion Criteria:

• Males and females, 18-70 years old
• BMI greater than or equal to 18.5
• BED as assessed by Structured Clinical Interview for DSM-5 Disorders (SCID-5-RV) OR Other Specified Feeding or Eating Disorder (OSFED) - Binge-eating disorder (of low frequency and/or limited duration) (SCID-5-RV) OR Bulimia Nervosa (BN) through excessive exercise and/or fasting to avoid gaining weight after episodes of binge eating. For individuals with OSFED-BED, the frequency of subjective and objective binge eating episodes will meet the frequency (Criterion D) for BED.

Exclusion Criteria:

• Substance use disorder active within the last 6 months, or clinical suspicion of ongoing substance use disorder at the discretion of the study clinician at the time of screening based on history and/or laboratory results
• Medication changes that have not reached steady state concentration, measured by the equivalent of 5 half-lives of that medication
• Use of medications for binge eating disorder or weight loss unless at a stable dose for at least 12 weeks
• History of any of the following medical conditions: inflammatory bowel disease or untreated thyroid disease
• Uncontrolled epilepsy (as defined by a seizure within the last 12 months)
• Clinically relevant ventricular arrhythmias, coronary heart disease, known long QTc, and hypertrophic cardiomyopathy
• Hematocrit >2% below normal
• Hemoglobin A1c >8%
• Use of insulin
• ALT or AST >2.5 times upper limit of normal
• Glomerular filtration rate < 60 mL/min
• Hyponatremia. Note that, in order to be randomized, subjects must have Na ≥ 135 mEq/L.
• Pregnancy or breastfeeding
• Unwilling to use a medically acceptable form of contraception throughout the study period (female of child-bearing potential only)
• History of psychosis or active suicidal ideation
• Major depressive disorder likely to require initiation or change in active treatment
• Borderline personality disorder as assessed by the McLean Screening Instrument for Borderline Personality Disorder (MSI-BPD)
• Current nicotine use, unless stable use for at least 12 weeks.
• Participation in any clinical study involving an investigational drug, device, or biologic within 1 month of randomization
• Any significant illness, condition, or medication that the Investigator determines could interfere with study participation and impact data collection or subject safety

Study staff and patients are blinded. The pharmacist is unblinded.