A Study to Investigate the Safety, Tolerability, and Pharmacokinetics and Pharmacodynamics Following Subcutaneous Injections of PG-102 (MG12) in Healthy Adult and Obesity Participants.

Inclusion Criteria: 1. Male or female participants, aged 18 to 65 years inclusive at the time of signing informed consent 2. Body mass index (BMI) of 18 to 30kg/m2 (inclusive) for Part A, Body mass index (BMI) of 25 to 30kg/m2 (inclusive) for Part B and Body mass index (BMI) 30 kg/m² or higher for Part C \[Exclusion Criteria\] 1. History of administration of prescription drugs, herbal medicines, over-the-counter drugs, or vitamin supplements within 10 days prior to the study or history of the following drugs and/or other foods within 90 days prior to screening: * Drugs that affect body weight (such as obesity medications, psychiatric drugs, beta blockers, diuretics, contraceptives, female hormones, proton-pump inhibitors (PPIs), H2 receptor antagonists, health functional foods/supplements, and formulas designed for weight control). * Drugs that have the potential to impact blood sugar, liver fat, and intestinal microorganisms (including GLP-1 receptor agonists, DPP-4 inhibitors, SGLT-2 inhibitors, thiazolidinediones (TZDs), fish oil, polyunsaturated fatty acids (PUFA), and ursodeoxycholic acid (UDCA)), as well as individuals who are currently using insulin. 2. History of gastrointestinal diseases (Crohn's disease, ulcers, acute or chronic pancreatitis, etc.) or gastrointestinal surgery (excluding simple appendectomy or hernia surgery) that may affect the absorption of clinical trial drugs. 3. History of acute proliferative retinopathy or maculopathy, severe gastroparesis, and/or severe neuropathy. 4. History of surgical treatment for obesity within 2 years (example: bariatric surgery, gastric banding etc) or gastrointestinal procedures for weight loss (including LAP-BAND®), or uncontrolled gastrointestinal disorders at Screening (e.g., peptic ulcer, gastroesophageal reflux disease).