Best if used with another method
Spermicide works best when paired with another method, like the diaphragm or condoms. You can use spermicide to make a barrier method more effective, but it’s not very effective if used alone.
You wouldn’t mind getting pregnant
If you plan to use spermicide alone, keep in mind that the failure rate is pretty high—28% for typical use.
No prescription necessary
If you can't make it to the doctor (or don't want to), you can always use spermicide. It's available at most drug stores and supermarkets. But why not pick up a pack of condoms while you're at it?
Some people are allergic
If you get irritated using spermicide, you're probably allergic to it. Unfortunately, all spermicides and contraceptive gels sold in the United States contain the same active ingredient, Nonoxynol-9. If you’re allergic to that, this method (and condoms with spermicidal lubricant) won’t work for you.
You’re confident you’re both HIV-free
Nonoxynol-9 causes changes in your sensitive skin down there that can make you more susceptible to HIV. If you or your partner have HIV or haven’t been tested recently, you may want to steer clear of this method.