Low-dose aspirin (75–100 mg/day) is effective in preventing atherothrombosis by irreversibly inhibiting platelet COX-1, which blocks thromboxane A₂ (TXA₂) production. This mechanism ensures consistent suppression of TXA₂, reducing the risk of coronary atherothrombosis and its recurrence, while increasing the risk of gastrointestinal bleeding. Low-dose aspirin also shows chemopreventive effects against colorectal and other digestive tract cancers, likely due to platelet inhibition rather than anti-inflammatory effects. Aspirin's pharmacokinetics are simple, with a short half-life and rapid resynthesis of acetylated COX-1 in nucleated cells, leading to consistent antiplatelet effects. It is more effective and safer than higher doses, with minimal interindividual variability. Low-dose aspirin is preferred over enteric-coated formulations in patients with a BMI >35 kg/m² or body weight >120 kg. Clinical trials show that low-dose aspirin reduces the risk of myocardial infarction, stroke, and vascular death in high-risk patients. It is effective in both primary and secondary prevention, with a lower daily dose (50–100 mg) being sufficient for long-term use. However, its efficacy in older adults is debated, as the ASPREE trial showed no significant reduction in cardiovascular events in elderly patients. Compared to other antiplatelet drugs like P2Y₁₂ inhibitors, low-dose aspirin has a similar bleeding risk but is more effective in preventing vascular events. While P2Y₁₂ inhibitors may offer some benefit in certain populations, their superiority over aspirin is not well established. Low-dose aspirin is generally safer than traditional NSAIDs, with a lower risk of gastrointestinal bleeding and renal toxicity. It does not impair renal function or blood pressure control, and its use is associated with a lower risk of heart failure. However, it may increase the risk of intracranial hemorrhage and cognitive impairment, though these risks are relatively low. Aspirin also has chemopreventive effects against colorectal cancer, likely due to its antiplatelet action. It may reduce the risk of colorectal adenoma recurrence and cancer development in high-risk individuals. In conclusion, low-dose aspirin remains a key therapeutic option for preventing atherothrombosis and cancer, despite the development of newer antiplatelet drugs. Its safety profile, effectiveness, and cost-effectiveness make it a preferred choice in many clinical settings. Further research is needed to fully understand its role in cancer prevention and to optimize its use in various patient populations.Low-dose aspirin (75–100 mg/day) is effective in preventing atherothrombosis by irreversibly inhibiting platelet COX-1, which blocks thromboxane A₂ (TXA₂) production. This mechanism ensures consistent suppression of TXA₂, reducing the risk of coronary atherothrombosis and its recurrence, while increasing the risk of gastrointestinal bleeding. Low-dose aspirin also shows chemopreventive effects against colorectal and other digestive tract cancers, likely due to platelet inhibition rather than anti-inflammatory effects. Aspirin's pharmacokinetics are simple, with a short half-life and rapid resynthesis of acetylated COX-1 in nucleated cells, leading to consistent antiplatelet effects. It is more effective and safer than higher doses, with minimal interindividual variability. Low-dose aspirin is preferred over enteric-coated formulations in patients with a BMI >35 kg/m² or body weight >120 kg. Clinical trials show that low-dose aspirin reduces the risk of myocardial infarction, stroke, and vascular death in high-risk patients. It is effective in both primary and secondary prevention, with a lower daily dose (50–100 mg) being sufficient for long-term use. However, its efficacy in older adults is debated, as the ASPREE trial showed no significant reduction in cardiovascular events in elderly patients. Compared to other antiplatelet drugs like P2Y₁₂ inhibitors, low-dose aspirin has a similar bleeding risk but is more effective in preventing vascular events. While P2Y₁₂ inhibitors may offer some benefit in certain populations, their superiority over aspirin is not well established. Low-dose aspirin is generally safer than traditional NSAIDs, with a lower risk of gastrointestinal bleeding and renal toxicity. It does not impair renal function or blood pressure control, and its use is associated with a lower risk of heart failure. However, it may increase the risk of intracranial hemorrhage and cognitive impairment, though these risks are relatively low. Aspirin also has chemopreventive effects against colorectal cancer, likely due to its antiplatelet action. It may reduce the risk of colorectal adenoma recurrence and cancer development in high-risk individuals. In conclusion, low-dose aspirin remains a key therapeutic option for preventing atherothrombosis and cancer, despite the development of newer antiplatelet drugs. Its safety profile, effectiveness, and cost-effectiveness make it a preferred choice in many clinical settings. Further research is needed to fully understand its role in cancer prevention and to optimize its use in various patient populations.