The Messenger of Allah ﷺ used to recite this prayer for healing, "Remove the affliction, Lord of mankind. In Your hand is the cure. None can lift it but You."
أن رسول الله ﷺ كان يرقي يقول: امسح الباس رب الناس بيدك الشفاء لا كاشف له إلا أنت.
Bukhari narrated it in the Book of Medicine (5744), and Muslim in the Book of Greetings (2191:49), both from the hadith of Hisham bin Urwa, from his father, from Ayesha, and I have mentioned it. The wording given is Bukhari's, and Muslim's wording is similar, except that it does not contain "Wipe away the harm," but rather contains "Take away the harm."