Do glycerin tinctures work? if so, how long does it take to work?

okay, so i bought a 1 oz. bottle of glycerin tincture from the dispensary and dropped some, didnt feel anything. i waited 20 minutes then dropped some more and still havent felt much. its gotten me a little buzz but my understanding was that it was supposed to get you pretty high. im sure it is supposed to work since it is sold at the dispensary. but shouldn't it hit instantly?