Nonoxynol-9

Nonoxynol-9

Clinical data
Other names	26-(Nonylphenoxy)-3,6,9,12,15,18,21,24-octaoxahexacosan-1-ol
Routes of administration	topical
Legal status
Legal status	In general: legal
Pharmacokinetic data
Excretion	not applicable
Identifiers
IUPAC name 2-[2-[2-[2-[2-[2-[2-[2-[2-(4-nonylphenoxy) ethoxy]ethoxy]ethoxy]ethoxy]ethoxy]ethoxy] ethoxy]ethoxy]ethanol
CAS Number	26571-11-9
PubChem CID	72385
CompTox Dashboard (EPA)	DTXSID00858720
ECHA InfoCard	100.110.408 100.043.454, 100.110.408
Chemical and physical data
Formula	C33H60O10
Molar mass	616.823 g/mol g·mol−1
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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. However, its use is controversial because it may cause genital lesions.

Uses

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.

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 pregnancy and STD prevention in the event of condom failure. However, the 2001 WHO/CONRAD Technical Consultation on Nonoxynol-9 concluded:

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 have a shorter expiration date.

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 Cream

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

Side effects

Nonoxynol-9's ability to kill microbes in vitro was initially taken as evidence that it might be effective at preventing STD transmission. However, more recent findings indicate that it may actually increase a person's risk of contracting STDs, especially if used frequently. This is because the chemical causes tiny abrasions inside the sensitive vaginal and anal walls.

From 1996 to 2000, a UN-sponsored study carried out in several locations in Africa followed nearly 1000 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 have led most major health agencies to recommend that it no longer be used by women at high risk of HIV infection. The WHO further notes that "Nonoxynol-9 offers no protection against sexually transmitted infections such as gonorrhoea, chlamydia."

Regular use of nonoxynol-9 appears also to increase the risk of infection with sexually transmitted human papillomaviruses (HPVs) that can cause cervical cancer. In one of the studies, researchers at the National Cancer Institute also reported that the increased likelihood of HPV infection caused by N-9 was mitigated through the use of carrageenan-based lubricants mixed 1:1 with N-9. Two consumer products containing carrageenan, Divine No. 9 and BIOglide, prevented detectable HPV infection in the study.

Alternatives

Two alternatives to nonoxynol-9 spermicide are:

• Menfegol: Available as a foaming tablet in Europe.
• Benzalkonium chloride: The active ingredient in one brand of contraceptive sponge, available only in France.

External links

• Safety of Nonoxynol-9 when used for contraception World Health Organization (October 2001)
• Vaginal Spermicide: Nonoxynol Family Practice Notebook.com
• Docs: 'Nonoxynol-9 Doesn't Work' Wired News: Lite, Jordan (May 13, 2002)
• Femprotect alternative to nonoxynol-9
• Info on microbicides
• Condoms containing nonoxynol-9, present a risk to users.
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