What are spermicides?
Spermicides are a form of chemical contraception that work by killing or stopping sperm on contact, thus making the sperm inactive and unable to pass through the cervix to fertilise an egg.
Spermicides come in a variety of forms – creams, gels, foams, suppositories, tablets and films – but are currently not available in Australia.
How do they work?
Spermicides are applied deep into the vagina, close to the cervix, before sex to prevent sperm from entering the uterus. After sex, sperm normally swim up the vagina, through the cervix and into the uterus and then up the fallopian tubes. It takes one to 2 hours for sperm to reach the ends of the fallopian tubes. The sperm usually meet the egg in the outer one-third of the fallopian tube. However, the spermicide blocks the uterus and also immobilises sperm so they can't swim, thus preventing them from reaching the egg in the fallopian tube.
The chemical most commonly used in spermicides is called nonoxynol-9.
How effective are they?
Spermicides are not considered an effective form of contraception on their own, but they can be used in conjunction with a barrier method of contraception such as condoms, diaphragms and cervical caps.
If spermicides are used as the only form of contraception, up to 28 per cent of women may become pregnant within a year.
Risks of spermicide use
Frequent use of certain spermicides may increase the risk of getting a sexually transmitted infection (STI), including HIV, from an infected partner.
Some people have allergies to spermicides or find they irritate the vagina, causing burning, rash or itching. They may cause irritation to their partner's penis or a burning feeling on urination. If this happens you could try another brand to find one that works for you.
There is also a suggestion that using spermicides increases the risk of a urinary tract infection (UTI) in women, potentially by damaging the normal bacterial flora of the vagina and by increasing irritation.
Some of the advantages of spermicides are that they:
- are easy to use;
- don't require a prescription;
- do not affect the menstrual cycle; and
- increase lubrication during sex.
Some of the disadvantages of spermicides are that they:
- do not provide protection from sexually transmitted infections (STIs);
- are not considered an effective form of contraception when used alone;
- may produce side effects such as vaginal or penile irritation;
- may increase the risk of developing urinary tract infections (UTIs);
- must be applied at the correct time, and reapplied with subsequent sex acts; and
- must remain in place for 6-8 hours after ejaculation to make sure all sperm are killed.
You should apply the spermicide into your vagina, usually with an applicator, as high as possible, before intercourse, but not more than 30 minutes before having sex. You should follow the package instructions carefully, and re-apply the spermicide if sexual intercourse is repeated or delayed. You must also wait 6-8 hours afterwards before rinsing or douching.
Spermicide suppositories are inserted high into the vagina by hand. If you are using spermicide with a diaphragm, apply it to the upper side that will be in contact with the cervix. If you have sex again apply additional spermicide without removing or dislodging the diaphragm.
2. Family Planning NSW. The diaphragm (updated Feb 2015). http://www.fpnsw.org.au/161410_8.html (accessed Jan 2016).
3. MayoClinic.com. Spermicide (updated Jan 2016). http://www.mayoclinic.org/tests-procedures/spermicide/home/ovc-20168558?reDate=03062015 (accessed Jan 2016).