assalam wa allykum
is it permissible to use zamzam water to apply on the place of pain?
may Allah reward you with good

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

It is permissible to pour Zam-Zam water on the place of pain in the body, but it is better to drink it with the intention of seeking cure because it is confirmed that the Prophet said: “Zam-Zam water is (good) for what it is drunk for.”

For more benefit, please refer to Fatwa 87528.

Allaah Knows best.