Inclusion Criteria:
1. Subjects aged 18-70 years, both genders.
2. BMI:
* Cohorts 1-6: 25-34.9
* Cohort 7: 30.0-44.9
3. HbA1c \<6.5%
4. Healthy as determined by a physician, based on history, medical examination, vital signs, laboratory tests, cardiac monitoring and respiratory function. History must comply with the following:
1. Absence of clinically significant illness or major surgery within the preceding 12 weeks.
2. Absence of clinically significant history of neurological, endocrine, cardiovascular, pulmonary, hematological, immunologic, psychiatric, gastrointestinal, renal, hepatic, and/or metabolic disease as per PI decision.
5. Male subjects with female partners of childbearing potential must agree to utilize an approved contraceptive during the study.
6. Female subjects of child-bearing potential with negative urine pregnancy test at screening and who agree to use contraception during the study.
7. Female subjects of non-child-bearing potential (i.e. tubal ligation, hysterectomy, or postmenopausal).
8. Subjects must provide written informed consent and be willing and able to comply with study procedures.
Exclusion Criteria:
1. History of excessive alcohol use (defined as \>21 drinks per week for males and \>14 drinks per week for females), recreational drug use within the past three months, or failure on urinary drug screen. Note: use of Cannabinoids for medical purposes is allowed.
2. Pregnant or breastfeeding within six months of screening assessment.
3. Substantial changes in eating habits or exercise routine within the preceding three months.
4. Evidence of eating disorders.
5. \>5% weight change in the past three months.
6. Bariatric surgery within the past five years.
7. Moderate renal impairment ( Glomerular filtration rate\<60 mg/mL/1.73m2)
8. Liver function tests greater than twice the upper limit of normal upon repeated measurements.
9. Diseases interfering with metabolism and or ingestive behavior (e.g., myxedema, Cushing's disease, schizophrenia, major psychoses, unmanaged depression).
10. Use of medications affecting body weight within the past three months, unless on a stable dose, with weight stability in the preceding three months. These medications include:
1. Drugs approved for the treatment of obesity
2. Cyproheptadine or medroxyprogesterone
3. Atypical anti-psychotic drugs
4. Tricyclic antidepressants
5. Lithium, MAO's, glucocorticoids
6. SSRIs or SNRIs
7. Anti-epileptic drugs
11. Any clinically significant abnormality following the Investigator's review of the physical examination and clinical laboratory tests.
12. A baseline (screening echocardiogram result) prolongation of ventricular activation and recovery interval after repeated measurements of \>450 milliseconds; a history of unexplained syncope, cardiac arrest, unexplained cardiac arrhythmias or torsades de pointes, structural heart disease, or a family history of Long QT Syndrome.
13. Use drugs of abuse within the preceding three months.
14. The last dose of an investigational drug in other clinical trial was within the month prior to dosing in the present study. Note: Volunteers from the previous Phase 1a trial (MD-18-01) may be recruited for the current study, provided that at least 12 weeks have passed since their last dose of the investigational product.
15. A positive result for any of the following tests: hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency viruses (HIV) and Treponema pallidum.
