Allah the almighty says in Qur'an;
We reveal the Qur'an, which is the cure and mercy for believers; and it adds nothing to the unjust but loss. (Qur'an 17,82)
Imam Ibn Qayyim Al-Jauziyah related in his book (Prophetic Medicine).
"I happened to get sick while was in Mecca. in the absence of medical help and pharmacy, I did following: I took a sip of water from Zamzam and I recited Al-Fatiha several times on it before drinking. I found complete health. Then I got used to it and repeat it the most of the time when I felt pain, I got desired result."