This study is the first time SA030 is being given to people. The goal is to understand how safe it is, how well it is tolerated, and how the body processes and responds to a single dose of SA030 in individuals who are overweight or obese.

Over the last few decades, more and more people around the world have become overweight or obese, and the numbers keep rising in almost every country. From 1990 to 2021, this problem grew steadily and reached its highest point in 2021.

Inclusion Criteria:

• You must be able to understand the study and sign a written consent form.
• Men or women aged 18 to 55 years can join
• Overweight or obese with a body mass index (BMI) between 25-40 kg/m^2(inclusive);
• You should be generally healthy, The study doctor will check your medical history, vital signs, physical exam, blood and urine tests, Electrocardiogram, and abdominal. ultrasound. Minor issues are okay if the doctor thinks they are not medically important.
• For female participants of childbearing potential: must be non-pregnant and non- lactating, and agree to use highly effective contraception throughout the study period;
• For male participants of reproductive potential: must agree to use highly effective contraception during the study period to ensure effective contraception for sexual partners.

Exclusion Criteria:

• You cannot join if you have lost or gained more than 5 percent of your body weight in the last 3 months.
• You cannot participate if you previously had, or plan to have, weight-loss surgery or a weight-loss device during the study, except for the following procedures done more than 1 year before screening
• Use of any over-the-counter medications, herbal supplements, or health products that may significantly affect weight or metabolism within 1 month prior to screening (e.g., orlistat, garcinia cambogia, ephedrine, etc.)
• At screening, sitting systolic blood pressure more than of equals to 160 milli meters of mercury and/or diastolic blood pressure more than of equals to 100 mmHg, and deemed unsuitable for participation in this study by the investigator;
• Severe psychiatric disorders or uncontrolled psychiatric conditions, including but not limited to schizophrenia, bipolar disorder, or depression, deemed unsuitable for participation in this study by the investigator;
• If the screening ECG shows a prolonged QT/QTc interval, and a repeat test confirms QTcF greater than 450 ms in males or greater than 470 ms in females, the participant will be excluded
• Suffering from severe diseases, including but not limited to disorders of the nervous system, cardiovascular system, hematopoietic and lymphatic system, immune system, digestive system, urinary system, respiratory system, endocrine system, and history of malignancies, which the investigator judges may compromise safety or influence study results;
• Co-infection with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), or syphilis; or prior diagnosis of hepatitis A, D, or E without resolution;
• Individuals who received a vaccine or live attenuated vaccine within 1 month prior to dosing, or who plan to receive a vaccine during the trial period; Major surgery within 6 months prior to screening, or planned surgery during the study period;
• Severe infection or trauma within 4 weeks prior to screening;
• Non-physiological blood loss more than or equals 200 milliliter within 1 month prior to study drug administration (including trauma, blood collection, or blood donation), or individuals planning to donate blood during the study period or within 60 days after dosing;
• History of severe intolerance to subcutaneous injections (mild reactions such as local swelling or redness are permissible);
• Individuals who have taken any prescription medication, herbal supplements, or over-the-counter drugs within 14 days prior to study drug administration;
• Participation in other drug clinical trials within 3 months of this study's treatment initiation, or within 5 half-lives of other investigational drug exposure, or participation in siRNA or antisense oligonucleotide drug clinical trials within 6 months prior to this study's treatment initiation (participants who withdrew from the study before receiving the investigational drug may be eligible for this study);
• Individuals who smoked more than 5 cigarettes or an equivalent amount of tobacco daily within 3 months prior to screening, or who are unable to abstain from smoking during the trial hospitalization period;
• Weekly alcohol consumption exceeding 14 units within 3 months prior to screening (1 unit of alcohol ≈360 milli Liter beer or 45 milli Liter 40 percent alcohol spirits or 150 milli Liter wine), or those with a positive breath alcohol test on the day before dosing (breath alcohol content more than 0.0 milligram per100 mL), or those unable to abstain from alcohol during the trial hospitalization period;
• Current or former drug users/substance abusers, or those with a positive urine drug screen on the day before dosing;
• Other factors deemed unsuitable for trial participation by the investigator, such as potential for poor compliance.