DXM (dextromethorphan hydrobromide) is a cough suppressant which when ingested in high doses causes the user to fall into a dissociative psychedelic trip.
DXM important links to check out:
https://drugs-forum.com/threads/beginners-guide-to-dxm.6084/
https://erowid.org/chemicals/dxm/faq/dxm_experience.shtml
https://erowid.org/chemicals/dxm/