How many mg of aspirin per tablet needs to be determined on a case-by-case basis, as aspirin comes in different dosage forms, and different dosage forms have different specifications. 1. Aspirin tablets: drug specifications are 0.05g, 0.1g, 0.3g, 0.5g; 2. Aspirin enteric-coated tablets: drug specifications are 0.025g, 0.04g, 0.05g, 0.1g, 0.3g; 3. Aspirin enteric-coated extended-release tablets: drug specifications are usually 0.05g; 4. aspirin effervescent tablets: drug specifications are 0.1g, 0.3g, 0.5g. Aspirin has more adverse reactions, the more common are gastrointestinal reactions such as nausea, vomiting, epigastric pain, etc., if long-term or large doses may appear gastrointestinal bleeding or ulcers; central nervous such as reversible tinnitus, hearing loss; allergic reactions: such as urticaria, angioneurotic edema, asthma, or shock; reversible liver and renal function impairment. Therefore, aspirin should be taken correctly under the guidance of a doctor, and is contraindicated in patients with severe heart failure, hemophilia or thrombocytopenia, and infants under 3 months of age.