Legal Drug, known in Japan as Gōhō Doraggu (合法ドラッグ) is a manga series by CLAMP. It is published in Japan by Kadokawa Shoten and it is published in English by TokyoPop. The manga also goes by the title 'Lawful Drug'.

It is about Kazahaya Kudo and Rikuo Himura, who are indebted to work for the owner of the Green Drug Pharmacy and fill out illegal prescriptions at night.

The story begins with Kazahaya, collapsing in the snow one night about to die. He is rescued just in time by a mysterious young man, Rikuo. With no memories of his past, Kazahaya finds himself indebted to Kakei, Rikuo's employer, and working with Rikuo, his new roomate, at a pharmacy called Green Drug. While their day job is quite simple, both Kazahaya and Rikuo are forced by Kakei to make rather strange deliveries by night, because of their supernatural powers. While Kazahaya possesses certain abilities akin to clairvoyance and psychometry, where he can see the memories of people by touching the person himself or an object they have left, Rikuo has strong telekinetic powers. Both the main characters have dark pasts, which are revealed as the series progresses, mostly by Kakei, who has clairvoyant abilities of his own.