Minoxidil and Itch: Am I allergic to Minoxidil?

Some individuals who use minoxidil solution develop itching in the scalp.  In most cases, this is not due to an allergy to the minoxidil but rather due to irritation from a chemical that is mixed with the minoxidil. This chemical is called propylene glycol. If patients have a lot of itching with minoxidil, a minoxidil formulation that does not contain propylene glycol can be recommended.  A common example of a proplylene glycol free product would be minoxidil 5% foam or minoxidil compounded by the pharmacist in glycerin, water and ethanol.

Very rarely, a patient can be truly allergic to minoxidil. Specialized allergy testing performed by a dermatologist (called patch testing) can help to determine if a patient is actually allergic to minoxidil.  Usually such testing is only performed in complex or challenging situations.