Spermicides are composed of a spermicidal agent in a carrier that allows dispersion and retention of the agent in the vagina.

Available preparations

Nonoxinol-9 is the most commonly used spermicidal agent and is the active component in the prescribable spermicidal agents available in the UK. Spermicidal contraceptives are useful additional safeguards, but do not give adequate protection if used alone, except where fertility is already significantly diminished. They are suitable for use with barrier methods such as the cap and diaphragm.^1,2

Spermicides are available as:

• Aerosol foam
• Jelly
• Cream¹
• Film
• Sponge
• Pessary

Efficacy

Spermicides are no longer recommended as an addition to condom use, as they are neither necessary for contraceptive efficacy of condoms nor useful for infection protection.

• Because of poor trial quality, how well various spermicides work in preventing pregnancy is unclear. However, it is known that gel with the smallest amount of nonoxinol-9 is less effective in preventing pregnancy than products containing more of the same ingredient.³
• Two large randomised controlled trials in developing countries compared whether protection was provided against gonorrhoea, chlamydial infection and HIV-1 infection with gel formulations containing nonoxinol-9.^4,5 The studies found that the spermicidal agent offered no clinical benefit; and so currently the extent to which protection may be provided by use of spermicidal agents is inconclusive.
• Avoid spermicides in men and women who might be at high risk of infection, as multiple use of spermicide may cause irritation to the vagina and rectum, increasing the chance of infection.
• Spermicides should be used by women at low risk of infection who wish to use either a cap or diaphragm. When used correctly and consistently with spermicide, latex diaphragms and cervical caps are estimated to be between 92% and 96% effective in preventing pregnancy.⁶ Cochrane reviews have found them to be more effective than use with a contraceptive sponge.⁷

Mode of action

Diaphragms and caps are barrier methods of contraception and therefore prevent fertilisation. They cover the cervix, acting as a barrier blocking the cervix as well as providing a reservoir for spermicide. Spermicide works by:

• Altering the integrity of the sperm cell membrane.
• Altering the vaginal pH, causing a hostile environment for sperm.

Advantages

• They provide lubrication.
• Spermicides are thought to increase the effectiveness of the diaphragm, and it remains common practice to use a spermicide with a diaphragm. However, a recent Cochrane review only found one (under-powered) study that indicated a trend towards lower pregnancy rates with this strategy.⁸

Disadvantages

• Pessaries need to be inserted 30 minutes before intercourse.
• Spermicides are only effective for 60 minutes.
• They may cause irritation and, rarely, allergy.⁹
• They can be perceived as messy.
• They may have an unpleasant odour or taste.^9,10

Document references

1. Summary of Product Characteristics - (SPC) Gygel® contraceptive jelly (2.0% w/w of nonoxinol-9), Janssen-Cilag Ltd, electronic Medicines Compendium. Updated Jan 2011
2. Female Barrier Methods, Faculty of Family Planning and Reproductive Health Care (2007)
3. Grimes DA, Lopez L, Raymond EG, Halpern V, Nanda K, Schulz KF. Spermicide used alone for contraception. Cochrane Database of Systematic Reviews 2005, Issue 4. Art. No.: CD005218. DOI: 10.1002/14651858.CD005218.pub2
4. Roddy RE, Zekeng L, Ryan KA, et al; Effect of nonoxynol-9 gel on urogenital gonorrhea and chlamydial infection: a randomized controlled trial.; JAMA. 2002 Mar 6;287(9):1117-22. [abstract]
5. Van Damme L, Ramjee G, Alary M, et al; Effectiveness of COL-1492, a nonoxynol-9 vaginal gel, on HIV-1 transmission in female sex workers: a randomised controlled trial.; Lancet. 2002 Sep 28;360(9338):971-7. [abstract]
6. Male and Female Condoms, Faculty of Family Planning and Reproductive Health Care (2007)
7. Kuyoh MA, Toroitich-Ruto C, Grimes DA, et al; Sponge versus diaphragm for contraception: a Cochrane review. Contraception. 2003 Jan;67(1):15-8. [abstract]
8. Cook L, Nanda K, Grimes D; Diaphragm versus diaphragm with spermicides for contraception; Cochrane Database Syst Rev. 2003;(1):CD002031. [abstract]
9. Belfield, T. (Ed.) FPA contraceptive handbook: a guide for family planning and other health professionals. 3rd edn. London: Family Planning Association. (1999)
10. The Consensus Committee of the Society of Obstetricians and Gynaecologists of Canada (1998) The Canadian consensus conference on contraception. Journal SOGC 20(8), 1-75