The goal of this clinical trial is to learn if semaglutide works to treat acute ischemic stroke (AIS). It will also learn about the safety of semaglutide in AIS. The main question it aims to answer is: Does semaglutide improve the 90-days functional outcome in participants with acute large vessel occlusion who receive the endovascular treatment (EVT)? Researchers will compare semaglutide injection to non-injection to see if semaglutide works to improve the functional outcome in participants with EVT.

Participants will:

• Receive 0.5mg semaglutide injection before (Day 0) and 1 week (Day 7) after EVT , or EVT alone.
• Have additional blood test before and after EVT.
• Receive neurological assessment before EVT, Day 1, Day 3, Day 5-7 after EVT or on hospital discharge (whichever earlier), Day 90±14 after EVT. Audio or video of the assessment may be recorded if possible.
• Receive brain CT + CT angiogram + CT perfusion and MRI after EVT, where the CT scan may be repetitive.

Inclusion Criteria:

1. LVO stroke at terminal ICA, M1 or dominant M2 with an LKW-to-randomization ≤24 hours
2. Age ≥ 18 years old
3. National Institute of Health Stroke Scale ≥ 6 at the time of brain imaging
4. Acute LVO stroke due to thromboembolism or intracranial stenosis
5. Patients who received computer tomographic or magnetic resonance angiography
6. ASPECTS ≥ 6 for patients with LKW-to-randomization ≤6 hours
7. Salvageable ischemic penumbra demonstrated by CT perfusion or MRI for patients with LKW-to-randomization between 6 and 24 hours
8. Informed consent obtained from patient or acceptable patient surrogate.

Exclusion Criteria:

1. Use of intravenous thrombolytic therapy (alteplase or tenecteplase)
2. Pre-stroke mRS > 2 for patients <80 years and > 1 for patients ≥ 80 years old
3. Intracranial hemorrhage or brain tumour on initial imaging (except small meningiomas)
4. Simultaneous occlusion of bilateral anterior circulation, or both anterior and posterior circulation
5. Unstable hemodynamics on presentation that require resuscitation
6. Systolic blood pressure >185mmHg or diastolic blood pressure >110mmHg that cannot be controlled by antihypertensive drugs
7. Severe comorbid illness, e.g. terminal malignancy with life expectancy <1 year
8. Pregnant or lactating female
9. Participation in another clinical trial
10. Contraindications to GLP1-RA, including history of allergy to GLP-1RA, family or personal history of multiple endocrine neoplasia, medullary thyroid or pancreatic carcinoma, or proliferative diabetic retinopathy
11. Blood glucose <2.7 or > 22.2 mmol/L; platelet count <50x10^9 /L; INR >1.7
12. Patients with known estimated glomerular filtration rate of <30ml/min/1.73m2 or creatinine >3mg/dL (265.2µmol/L); chronic liver disease with Child's Pugh score C or above; or recurrent unexplained hypoglycemia.
13. Suspected or confirmed vasculitis of the central nervous system
14. Unable to complete 90-day follow-up assessment