Tetracycline maximum dosage is how much there is no fixed figure, generally 1~2g a day, tetracycline has adverse reactions and contraindications, should be directed by a doctor to use the drug. Adults take tetracycline, 0.25-0.5g once every six hours, 1~2g a day; children over 8 years old take tetracycline, 6.25-12.5mg/kg, the specific dosage of children’s weight shall prevail. Tetracycline belongs to antibiotics, with bactericidal and anti-inflammatory effects. Adverse reactions such as abdominal distension, nausea, vomiting, diarrhea, headache, urticaria, etc. may occur after taking tetracycline. Tetracycline is contraindicated for those who are allergic to tetracyclines, children under 8 years of age, and breastfeeding mothers, and should be used with caution in pregnant women and patients with pre-existing renal impairment. Tetracycline should be taken by a doctor to guide the dosage of medication, not self-medication.