WordNet sense 1 (remedy that prevents or slows the course of an illness or disease):

preventative, prophylactic

WordNet sense 2 (any obstruction that impedes or is burdensome):

encumbrance, hindrance, hitch, interference, incumbrance, hinderance

WordNet sense 3 (an agent or device intended to prevent conception):

contraceptive, contraceptive device, birth control device, prophylactic device

WordNet sense 4 (tending to ward off):

cautionary

WordNet sense 5 (intended or adapted to afford protection of some kind):

protective

WordNet sense 6 (tending to discourage (especially of prices)):

prohibitive, prohibitory

WordNet sense 7 (made impossible):

obviating, preclusive

WordNet sense 8 (tending to deter):

deterrent

WordNet sense 9 (preventing movement):

hindering

WordNet sense 10 (conducive to good health of body or mind):

healthful