I asked the Messenger of Allah ﷺ, "Messenger of Allah, what do you say about incantations we use for healing, medicines we treat ourselves with, and precautions we take to protect ourselves? Do any of these turn back anything from the decree of Allah?"He replied, "They are themselves part of the decree of Allah."
حدثنا ابن أبي عمر حدثنا سفيان عن الزهري
سألت رسول الله ﷺ فقلت يا رسول الله أرأيت رقى نسترقيها ودواء نتداوى به وتقاة نتقيها هل ترد من قدر الله شيئا قال هي من قدر الله
Its chain is daif. Ibn Majah also narrated it in the Book of Medicine, chapter "Allah has not sent down any disease without sending down a cure for it," hadith no. 3437, from the hadith of Sufyan bin Uyayna, with the same wording, and it will come again at no. 2148. The hadith has other routes in Hakim, 1/32, and elsewhere. Ibn Abu Khuzama is of unknown standing, and Tirmidhi alone deemed him reliable.