Nonoxynol-9

Nonoxynol-9, sometimes abbreviated as N-9, is an organic compound that is used as a surfactant. It is a member of the nonoxynol family of nonionic surfactants. N-9 and related compounds are ingredients in various cleaning and cosmetic products. It is widely used in contraceptives for its spermicidal properties.

Spermicide
As a spermicide, it attacks the acrosomal membranes of the sperm, causing the sperm to be immobilized. Nonoxynol-9 is the active ingredient in most spermicidal creams, jellies, foams, gel, film, and suppositories.

Lubricant
Nonoxynol-9 is a common ingredient of most vaginal and anal lubricants due to its spermicidal properties.

A 2004 study found that over a six-month period, the typical-use failure rates for five nonoxynol-9 vaginal contraceptives (film, suppository, and gels at three different concentrations) ranged from 10% to 20%.

Condoms
Many models of condoms are lubricated with solutions containing nonoxynol-9. In this role, it has been promoted as a backup method for avoiding pregnancy and a microbicide for sexually transmitted diseases in the event of condom failure. However, the 2001 WHO / CONRAD Technical Consultation on Nonoxynol-9 concluded that: ''There is no published scientific evidence that N-9-lubricated condoms provide any additional protection against pregnancy or STDs compared with condoms lubricated with other products. Since adverse effects due to the addition of N-9 to condoms cannot be excluded, such condoms should no longer be promoted. However, it is better to use N-9-lubricated condoms than no condoms.''

Compared to regular lubricated condoms, condoms containing nonoxynol-9 present another disadvantage — they are limited by the shelf-life of the spermicide.

Cervical barriers
Almost all brands of diaphragm jelly contain nonoxynol-9 as the active ingredient. This jelly may also be used for a cervical cap. Most contraceptive sponges contain nonoxynol-9 as an active ingredient.

Shaving cream
Nonoxynol-9 is sometimes included in shaving creams for its properties as a nonionic surfactant; it helps break down skin oils that normally protect hair from moisture, so that they become wet and, hence, softer and easier to shave. Gillette formerly used nonoxynol-9 for this purpose in its Foamy products, but has discontinued the practice.

Sports cream
Nonoxynol-9 is also found in Bengay Vanishing Scent as an inactive ingredient.

Poison ivy creams
Nonoxynol-9 is also found in Zanfel poison ivy cream. It effectively helps to break up the oil urushiol that causes the rash.

Side effects
From 1996 to 2000, a UN-sponsored study conducted in several locations in Africa followed nearly 1,000 sex workers who used nonoxynol-9 gels or a placebo. The HIV infection rate among those using nonoxynol-9 was about 50% higher than those who used the placebo; those using nonoxynol-9 also had a higher incidence of vaginal lesions, which may have contributed to this increased risk. Whereas these results may not be directly applicable to lower-frequency use, these findings combined with lack of any demonstrated HIV-prevention benefit from nonoxynol-9 use led the World Health Organization to recommend that it no longer be used by those at high risk of HIV infection. The WHO further notes that "Nonoxynol-9 offers no protection against sexually transmitted infections such as gonorrhoea, chlamydia." A 2006 study of a nonoxynol-9 vaginal gel in female sex workers in Africa concluded that it did not prevent genital human papillomavirus (HPV) infection and could increase the virus's ability to infect or persist.