The Hidden Dangers of Nonoxynol-9

The Spermicide Can Actually Increase Your Risk of STDs

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Many people think that if a little bit of spermicide is good, than a lot of spermicide is bound to be better. But that theory is actually incorrect. It turns out that many spermicides, when used in excess, can make sex more hazardous. They can actually increase your risk of getting or giving someone a sexually transmitted disease (STD).

What is a Spermicide?

A spermicide is any compound that can be used to kill sperm.

Spermicides are used in many contraceptives, These products come in several forms. Contraceptive foams, creams, suppositories, and films all contain spermicides. Furthermore, spermicides are needed for diaphragms and cervical caps to be effective.

Many spermicides currently available in the United States contain nonoxynol-9 (N-9). N-9 is also the spermicide in the Today sponge. Other spermicides, and spermicidal microbicides, are currently under development. Many are designed to avoid the problems currently being seen with N-9 use.

What is Nonoxynol-9 (N-9)

Nonoxynol-9 is basically a type of detergent. It disrupts the plasma membranes (outer barrier) of sperm and other cells. It has been shown in the laboratory to be quite effective at killing many STD pathogens, including HIV, herpes, chlamydia, and gonorrhea. Other commercial spermicides that contain oxtoxynol-9 are also detergents. These products have similar properties to nonoxynol-9.

Why is Nonoxynol-9 Problematic?

When used in high dosages, or when used frequently, N-9 causes two types of damage to the vaginal epithelium. (The layers of skin cells that line the vagina.) It causes inflammation of the vagina and cervix. It can also actually kill off layers of cells. Both of these actions render a woman more susceptible to infection by various sexually transmitted diseases.

They may also make it easier for her to transmit STDs to her partner.

Regular use of N-9 may increase a person's risk of HIV, herpes, and other sexually transmitted diseases. It may not even require frequent use for problems to be seen. At least one study done in mice has shown that just one vaginal dose of N-9 can increase susceptibility to herpes infection.

What Should I Do?

Not everyone needs to worry about N-9. However, it's good to have other options for practicing safe sex. That's particularly true if you have a lot of sex. It's also true for people who are at high risk of STDs.

  • Consider using non-lubricated condoms with your own N-9-free lubricant, or non-spermicidal condoms. This is particularly important if you have sexual intercourse more than once or twice a day. Lubricant is an important component of safe sex. However, it's important to use the right kind.
  • Talk to your doctor about possible alternative forms of contraception if you are using a diaphragm, cervical cap, or the Today sponge, and you are at risk of sexually transmitted infections. If you're in a mutually monogamous relationship with someone and you've both been tested, then the potentially increased STD risk may be less of a concern. STDs don't appear out of the blue. They're passed from one partner to another. 

    Sources:

    Cone RA, Hoen T, Wong X, Abusuwwa R, Anderson DJ, Moench TR. "Vaginal microbicides: detecting toxicities in vivo that paradoxically increase pathogen transmission" 2006. BMC Infectious Diseases: 6:90

    Gupta, G "Microbicidal spermicide or spermicidal microbicide?" 2005. Eur J Contr Repro Health Care: 10(4):212–218.

    Hillier SL, Moench T, Shattock R, Black R, Reichelderfer P, Veronese F. "In Vitro and In Vivo: The Story of Nonoxynol-9." 2005. JAIDS: 39(1):1-8.

    Moench TR, Mumper RJ, Hoen TE, Sun M, Cone RA. Microbicide excipients can greatly increase susceptibility to genital herpes transmission in the mouse. BMC Infect Dis. 2010 Nov 18;10:331. doi: 10.1186/1471-2334-10-331. PubMed PMID: 21087496; PubMed Central PMCID: PMC2996397.

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