多西环素（其国际非专利药品名称为“Doxycycline”）也称为“强力霉素”“伟霸霉素”“脱氧土霉素”或“去氧土霉素”，是四环素类抗生素的一种。多西环素能与tRNA结合，从而达到抑菌的效果，通常用于治疗各种感染。

多西环素是20世纪60年代由辉瑞公司发明并进行临床改进的一种半合成四环素类药，“强力霉素”是它的商品名。多西环素于1967年得到FDA批准，成为辉瑞公司首个需要患者每天服用一次的广谱抗生素。

Doxycycline is an antibiotic that is used in the treatment of a number of types of infections caused by bacteria and protozoa. It is useful for bacterial pneumonia, acne, chlamydia infections, early Lyme disease, cholera and syphilis. It is also useful for the treatment of malaria when used with quinine and for the prevention of malaria. Doxycycline can be used either by mouth or intravenously.