What length shall one go under the Ruqya (spell or Islamic recitation of some verses and supplication to help a patient get cured) to get cured?

Answer

Praise Be to Allah and Peace Be Upon His Messenger.

Referring to your question, Ruqya is used for prevention as well as cure. If it is used for cure, it can extend until the patient get cures and the symptoms disappear. It can also be used as long as one lives. It has its own effects especially if it is read with thoughtful consideration. Shaikh Muhammad Ahmad Hussain, the General Mufti (Muslim Legal Scholar), in the Palestinian Legal Verdict Council, was once asked about it, and he answered that there are two kinds of Ruqya. The first one which is mixed with polytheism and begging others than Allah, so this kind is haram and prevented. The other one is begging Allah and asking Him only, and this is allowed.

Prophet Muhammad (PBUH) said: “There is no harm in spells as long as they do not involve polytheism.” Related by Muslim

Thus, Prophet Muhammad (PBUH) spelled others, and he was also spelled. Aisha (RAA) narrated: “when the Prophet had a complaint he would blow on himself, ejecting saliva, reciting the Mu'awwidhat and wipe himself with his hand. She said, “When he suffered from the pain of which he died, I would blow on him ejecting saliva and recite the Mu'awwidhat as he did, and would take the Prophet’s hand to wipe him.” Related by Bukhari.

However, if you ask about a specialist who does this work for you, we recommend that a Muslim can do this for themselves. Ask Allah to cure you, and stay far from the prevented supplications.