What it does
Nonoxynol-9 is a compound often used in contraceptives to help prevent pregnancy.
Commonly used for: birth control, contraceptive purposes
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Source: Pharmacy and Medicines Regulatory Authority · fetched 2026-04-21 17:37:41 · updated 2026-09-29 04:33:05
About this medicine
Nonoxynol-9 is a compound often used in contraceptives to help prevent pregnancy.
What it treats
- birth control
- contraceptive purposes
How it works
Nonoxynol-9 works by preventing sperm from reaching an egg, thus reducing the chance of pregnancy.
Who it's for
This product is for individuals who are looking for a method of contraception.
AI-assisted summary grounded in BNF data - general information only, not medical advice. Always confirm with your pharmacist or doctor.
Clinical monograph: nonoxynol9
BNF-referencedNonoxynol-9 is a nonionic surfactant primarily used as a spermicide in contraceptive products. It works by disrupting the sperm cell membranes, leading to the immobilization and death of spermatozoa. Nonoxynol-9 is commonly found in various forms of contraceptive gels, foams, and films, offering a barrier method of contraception while also providing lubrication.
Indications
- Contraception
- Spermicide
Dosage
Children: Nonoxynol-9 is not indicated for use in children.
Adults: Apply as directed on the product label before intercourse. The exact dosage and administration will depend on the formulation used.
Mechanism of action
Nonoxynol-9 interacts with the lipids in the membranes of the acrosome and the midpiece of the sperm. The sperm membranes are lysed; the acrosome, neck and midpiece of the spermatozoa are loosened and then detached which results in their immobilization and death.
Pharmacodynamics
Nonoxynol-9 is effective due to its surfactant properties, which allow it to disrupt the lipid bilayer of sperm cell membranes. As a result, it causes the sperm to become non-motile and ultimately leads to their destruction, thereby preventing fertilization. Its efficacy as a spermicide is dependent on the concentration and the formulation used.
Pharmacokinetics
The pharmacokinetics of Nonoxynol-9 are not extensively documented due to its local action and limited systemic absorption. When used vaginally, it acts locally without significant systemic effects. The compound is rapidly cleared from the site of application and does not accumulate in the system.
Pregnancy
Nonoxynol-9 should not be used as a contraceptive method in pregnancy as it does not provide adequate protection against pregnancy.
Breast-feeding
Nonoxynol-9 is not known to pose any risk during breastfeeding, but caution is advised as its safety in lactating women has not been extensively studied.
Storage
Store in a cool, dry place away from direct sunlight. Keep out of reach of children.
Formulations
- Spermicidal gel
- Spermicidal foam
- Spermicidal film
AI-synthesized from BNF references - general information only, not a substitute for professional medical advice or the current BNF. Verify doses with a pharmacist.
Molecular reference: nonoxynol-9
PubChem CID 72385Molecular formula: C33H60O10
Mechanism of action
Nonoxynol-9 interacts with the lipids in the membranes of the acrosome and the midpiece of the sperm. The sperm membranes are lysed; the acrosome, neck and midpiece of the spermatozoa are loosened and then detached which results in their immobilization and death.
Source: PubChem (NCBI) · pathways from PathBank, Reactome, WikiPathways & PharmGKB.