The Prophet (peace be upon him) said “For every illness there is cure. If the cure matches the illness, improvement will take place by the permission of God.” (related by Jabir in the book of Sahih Muslim
The commitment and the dosage are very important factors to achieve a result from the medicine or herbs that been used.
Narrated Abu Said Al-Khudri: A man came to the Prophet and said, “My brother has some abdominal trouble.” The Prophet said to him “Let him drink honey.” The man came for the second time and the Prophet said to him, ‘Let him drink honey.” He came for the third time and the Prophet said, “Let him drink honey.” He returned again and said, “I have done that ‘ The Prophet then said, “Allah has said the truth, but your brother’s abdomen has told a lie. Let him drink honey.” So he made him drink honey and he was cured. (Volume 7, Book 71, Number 588: Sahih Bukhari: Muslim) .