What Is Nonoxynol-9? Uses, Dosage, and What You Need to Know in 2026

Nonoxynol-9 (N-9) is the active ingredient in most over-the-counter spermicide products sold in the United States. It has been in use as a contraceptive agent for more than 60 years and remains the only OTC spermicide ingredient approved in the US. This guide covers everything you need to know about nonoxynol-9 in 2026.

What Is Nonoxynol-9?

Nonoxynol-9 is a nonionic surfactant — a type of molecule with detergent-like properties. It is chemically composed of nonylbenzene with a nine-membered polyethylene glycol chain. In its role as a vaginal spermicide, it disrupts the lipid membranes of sperm cells, immobilizing and killing them before they can reach an egg.

Nonoxynol-9 is classified as a spermicide and belongs to the broader category of non-hormonal contraceptives. It is available without a prescription and can be found at pharmacies, grocery stores, and online retailers throughout the US.

Brand Names for Nonoxynol-9

Nonoxynol-9 is sold under several brand names in the United States, including:

VCF (Vaginal Contraceptive Film and Gel) — one of the most widely recognized N-9 brands

Encare — dissolvable suppositories

Conceptrol (Options Conceptrol) — prefilled gel applicators

Gynol II (Options Gynol II) — gel designed for use with diaphragms

Today Sponge — N-9-impregnated foam sponge with barrier function

What Is Nonoxynol-9 Used For?

The primary FDA-approved use of nonoxynol-9 is as a vaginal contraceptive (birth control) to prevent pregnancy. It can be used:

Alone as a standalone contraceptive (though not the most effective option)

With a male condom for added protection against pregnancy

With a diaphragm or cervical cap — required for these barrier methods to work effectively

Important: Nonoxynol-9 does NOT protect against sexually transmitted infections (STIs) including HIV. It should never be used as a substitute for condoms when STI prevention is the goal.

Dosage Forms and How to Use Nonoxynol-9

Nonoxynol-9 is available in multiple forms, each with different timing and usage instructions:

Gel (VCF Gel, Conceptrol, Gynol II): Insert one applicatorful vaginally before intercourse. Effective immediately and for up to 1 hour. Apply before each act of intercourse.

Film (VCF Film): Insert one film square deep into the vagina at least 15 minutes before intercourse. Effective for up to 1 hour.

Suppositories/Inserts (Encare): Insert one suppository vaginally at least 10–15 minutes before intercourse. Effective for up to 1 hour.

Sponge (Today Sponge): Wet the sponge and insert deep into the vagina before intercourse. Provides 24 hours of protection regardless of how many acts of intercourse occur. Leave in place at least 6 hours after last intercourse before removing.

How Effective Is Nonoxynol-9?

When used alone, nonoxynol-9 has a typical-use failure rate of 15–28% per year. That means 15–28 out of 100 women who use N-9 as their only contraceptive method will become pregnant over the course of a year. Effectiveness improves substantially when used with barrier methods:

N-9 + male condom: Combined typical-use effectiveness improves significantly

N-9 + diaphragm: Pregnancy rate approximately 12–17% per year with typical use

Who Should NOT Use Nonoxynol-9?

Nonoxynol-9 is not appropriate for everyone. Do not use N-9 if you:

Are allergic to nonoxynol-9 or develop significant irritation

Have a partner with HIV or are at elevated risk for HIV

Are pregnant

Have a history of toxic shock syndrome (for sponge specifically)

Where to Get Nonoxynol-9

Nonoxynol-9 products are available OTC at pharmacies, grocery stores, and online. If you're having trouble finding it locally, medfinder can call pharmacies near you to verify availability. Want to understand how it works? Read our guide on how nonoxynol-9 works.