The purpose of this study is to determine if administration of RM-131 is effective in improving appetite and gastrointestinal symptoms leading to the recovery of patients with anorexia nervosa in the outpatient setting.

Inclusion Criteria:

• DSM-IV criteria for anorexia nervosa, including weight <85% of ideal body weight (IBW) and amenorrhea for three months;
• Age 18-45 years old;
• Gastrointestinal tract symptoms;
• Non-hormonal method of birth control, which must be used throughout the study. Female patients unable to bear children must have this documented (i.e., tubal ligation, hysterectomy, or post-menopausal, defined as a minimum of one year since the last menstrual period and elevated FSH);
• Stable concomitant medications defined as no changes in regimen for at least 2 weeks prior to baseline;
• Able to provide written informed consent prior to any study procedures and be willing and able to comply with study procedures, including daily SC injections and completion of a daily injection log.
• Patient has a primary care physician or treatment team managing her care.

Exclusion Criteria:

• Use of hormone therapy (including but not limited to estrogen, progesterone) or hormonal methods of birth control (i.e., oral, implantable, or injectable) within eight weeks of screening; or Depo-Provera within six months of screening;
• Pregnancy, lactation or breastfeeding, or a positive serum or urine pregnancy test, within eight weeks of screening;
• History of diabetes mellitus;
• History of purging behaviors greater than once monthly within the last three months;
• Active substance abuse;
• Use of metoclopramide, erythromycin, 5HT3 anti-emetics, or opioid medications within 2 weeks prior to baseline. [Note: these drugs should also not be used post-baseline];
• Hematocrit < 30.0 %, hemoglobin < 10.0 g/dl, potassium < 3.0 mmol/L, fasting glucose > 100 mg/dL, creatinine > 1.5 mg/dL, AST or ALT > 1.5 times the upper limit of normal, or abnormal plasma thyroid stimulating hormone (TSH) level;
• Currently receiving parenteral feeding or enteral feeding, or presence of a nasogastric or other enteral tube for feeding or decompression;
• History of gastric surgery such as fundoplication, gastrectomy, gastric pacemaker placement, vagotomy, bariatric procedure, small or large bowel resection;
• Clinical suspicion, in the opinion of the investigator, of active or symptomatic peptic ulcer disease, cholelithiasis, colitis, celiac sprue, or inflammatory bowel disease;
• Active suicidal ideation;
• Beck Depression Inventory-2 score of ≥ 29;
• Current inpatient hospitalization;
• Allergic or intolerant of egg, milk, wheat or algae, as these are components of the GEBT test meal;
• Participation in a clinical study with an investigational medication or device within the 30 days prior to dosing in the present study;
• Any other reason, which in the opinion of the Investigator, including severe renal, hepatic or cardiac disease, would confound proper interpretation of the study or expose a patient to unacceptable risk.