Allahumma Rabban-nas, adhhibil-ba's, ishfi Antash-Shafi, la shifa'a illa shifa'uka, shifa'an la yughadiru saqama.
O Allah, Lord of mankind, remove the harm and heal, for You are the Healer. There is no healing except Your healing, a healing that leaves no illness behind.
Hadith — Sahih al-Bukhari and Sahih Muslim — General supplication for illness
Authenticity: General authentic supplication