▁s per mic ides ▁are ▁available . ▁ ▁However , ▁no ▁published ▁studies ▁on ▁the ▁effect iveness ▁of ▁la ctic ▁acid ▁in ▁prevent ing ▁pre gn ancy ▁appear ▁to ▁have ▁been ▁done ▁since ▁ 1 9 3 6 . ▁Thomas ▁Mo en ch , ▁a ▁former ▁assistant ▁professor ▁of ▁medicine , ▁has ▁said ▁that ▁research ▁into ▁ac ids ▁as ▁s per mic ides ▁has ▁" pre tty ▁much ▁been ▁abandoned ." ▁ ▁Ext ract ives ▁of ▁the ▁ne em ▁plant ▁such ▁as ▁ne em ▁oil ▁have ▁also ▁been ▁proposed ▁as ▁s per mic ides ▁based ▁on ▁labor atory ▁studies . ▁Animal ▁studies ▁of ▁cre ams ▁and ▁p ess aries ▁derived ▁from ▁ne em ▁have ▁shown ▁they ▁have ▁contra cept ive ▁effects , ▁however ▁tri als ▁in ▁humans ▁to ▁determine ▁its ▁effect iveness ▁in ▁prevent ing ▁pre gn ancy ▁have ▁not ▁yet ▁been ▁conducted . ▁ ▁Use ▁with ▁cond oms ▁S per mic ides ▁are ▁believed ▁to ▁increase ▁the ▁contra cept ive ▁effect iveness ▁of ▁cond oms . ▁ ▁However , ▁cond oms ▁that ▁are ▁s per mic id ally ▁lub ric ated ▁by ▁the ▁manufact urer ▁have ▁a ▁shorter ▁sh elf ▁life ▁and ▁may ▁cause ▁ur inary - t ract ▁in fe ctions ▁in ▁women . ▁The ▁World ▁Health ▁Organ ization ▁says ▁that ▁s per mic id ally ▁lub ric ated ▁cond oms ▁should ▁no ▁longer ▁be ▁promoted . ▁ ▁However , ▁they ▁recommend ▁using ▁a ▁non ox yn ol - 9 ▁lub ric ated ▁cond om ▁over ▁no ▁cond om ▁at ▁all