This study will evaluate the safety and tolerability of a dissolvable oral film containing a very small dose of capsaicin (the compound that produces the hot sensation in chili peppers) in adults with acute ischemic stroke. The film is designed to stimulate nerves in the mouth that may activate the sphenopalatine ganglion, a structure involved in regulating blood flow to the brain. The main purpose of this study is to determine whether the capsaicin film can be given safely to patients with acute ischemic stroke when started within 24 hours of symptom onset. Participants will be randomly assigned (like flipping a coin) to receive either the capsaicin oral film or a placebo film that looks and tastes similar but contains no capsaicin. Neither the participants nor the clinical team will know which film is given (double-blind). All participants will continue to receive standard medical care for acute ischemic stroke. After administration of the study film, participants will be closely monitored for side effects and changes in vital signs (blood pressure, heart rate, respiratory rate, temperature, and oxygen saturation) at prespecified time points up to 72 hours. The primary outcome is the frequency of adverse events related to the study product within 72 hours after treatment begins. Participants will also be followed clinically up to 3 months as part of usual stroke care. The results of this study will help determine whether this approach is safe and feasible, and whether further studies are warranted.