Ruling on using medicine that contains menthol
Question

Is menthol permissible in Islam? As my chemistry professor told me that menthol is an alcohol because it belongs to the hydroxyl group -OH.
I have difficulty in breathing at night, and I use nose drops but I have not been able to use them for a number of nights, so my doctor recommended other medicines that contain menthol.
I hope that you can help me as the matter is very important. May Allah bless you.
Praise be to Allah.Menthol is extracted from mint and is used in the manufacture of some medicines.
Dr. Muhiy al-Deen ‘Umar Labaniyyah– may Allah bless him – said:
Mint oil is colourless or greenish yellow and has a distinctive scent and tastes slightly bitter. It gives a feeling of coolness. It contains the compound menthol as well as limonine, carfon, phellandrene and -esters.
He also said:
The compound menthol is the main ingredient in essential oil of mint that is extracted from peppermint and is used in some medicines. Menthol is beneficial in reducing the severity of infectious diseases of the respiratory tract and of the nasal sinuses. Menthol rub applied to the skin is beneficial in dilating the blood vessels and giving a cool sensation that helps in reducing pain. It may be used in the form of a lotion to reduce itching on the skin (pruritus or urticaria). Administering a menthol compound by mouth acts as a carminative (i.e., it reduces intestinal gas). It is also used in the treatment of irritable bowel syndrome, where it helps to relax the muscles of the large intestine and reduces pain. Menthol compound is also used in the preparation of a number of traditional medicines for the treatment of coughing, cold symptoms and so on.
Article Na‘naa‘ al-Madeenah, published in Majallat Markaz Buhooth wa Diraasaat al-Madeenah, issue no. 11, p. 179, 183, 184
The fact that menthol belongs to the hydroxyl group -OH does not make it forbidden and it does not mean that it is an intoxicant.
We asked a specialist in the field of chemistry and he answered that this substance – menthol – is not an intoxicant.
The basic principle with regard to all drinks is that they are halaal (permissible) unless they are intoxicants or are harmful.
The mere presence of alcohol in a drink does not mean that it is haraam, unless it reaches the level of causing intoxication. If the amount of alcohol is small and well absorbed in the material, then the drink is not haraam.
It says in a statement of the Islamic Fiqh Council of the Muslim World League:
It is permissible to use medicines containing negligible amounts of well-absorbed alcohol required in manufacturing that cannot be substituted, so long as that medicine is prescribed by a doctor of good character. It is also permissible to use alcohol for external cleaning of wounds, to kill germs, and in creams and lotions that are used externally. End quote.
Qaraaraat al-Majma‘ al-Fiqhi al-Islami, p. 341
For more information please see the answer to questions no. 59899 and 105101.
And Allah knows best.