Get slug in header

Please what is (is there) any variable, which I can use to get slug in header template? I could do it probably by deleting everything before last “/” from the page address (so example.com/this-is-my-article -> this-is-my-article or example.com/tag/category-name -> category-name) but i wonder that this is not the standard way and that it must be somewhere reachable (i would prefer to not make new database query – run the loop again in header)

thx