Contraceptive creams and jellies Substances containing spermicide, which block sperm and prevent it from joining with an egg. These are over-the-counter, one time use barrier methods of birth control. They work best if used with a cervical cap, diaphragm, or condom. Sasha Co- Founder of Psych n Sex, previous writer and campus educator for the Kinsey Institute & published psychology researcher. Manhattan girl obsessed with post ww2 abstract expressionism, beet juice, vintage clothing & Scandinavia.