By Michal Schonbrun, MPH, CHES
Note: This article addresses medical and practical aspects of spermicides. For a discussion of halachic aspects of spermicides, please see our article "Barrier Methods."
Spermicides are chemical substances that damage sperm during marital relations. Because they are highly acidic, they block and immobilize sperm, preventing their passage into the cervix and uterus.
Spermicides are available in different forms: suppositories, jelly (gel); film strips, foams and creams. Noxynol-9, benzalkonium chloride & sodium cholate are the main active ingredients found in spermicidal products.
Good quality spermicides are effective for approximately three hours. Brands may differ so one should be sure to check before use. Spermicides should be unscented, unflavored, and non-staining. They also provide a degree of lubrication during intimacy.
Effectiveness of spermicides
Spermicidal effectiveness is based on three primary characteristics: the concentration/dosage of active ingredients; the longevity of action, and the time it takes for the substance to break down/soften and exit the body. When used correctly and consistently according to instructions, effectiveness rates are approximately 80-90%. When used incorrectly or inconsistently, or without prior insertion experience, effectiveness rates drop to 75-80%.
Spermicides are used alone or in combination with a barrier method, such as a diaphragm or a cervical cap. When used together with another barrier method, statistical effectiveness is higher.
A woman needs to learn and practice the skill of spermicide insertion before use in real time. It is important to read the product information insert. After reading, a woman can insert the spermicide deep inside the vagina, on a trial basis. This means that a woman should “test” the product, see how it feels once it is inside her body, and see how it exits the body hours later. Because spermicides differ in form and chemical concentration, a small percentage of women may report irritation, itching or mild allergic reaction/sensitivity to the product. If any of these symptoms appear, it is recommended to try another spermicidal product or to find another appropriate method. Learning how to use spermicides properly and effectively is a skill which needs to be learned and mastered, like any other skill. No one is an expert on the first try.
It is also possible that a man will experience a ‘reaction’ to the chemicals. If this occurs, another method should be chosen.
Instructions for Correct Use
Check to make sure the expiration date is valid before use. Some spermicides require a “waiting time” before relations take place. Suppositories and vaginal film should be inserted as deep as possible into the vaginal space (closest to the os, the cervical opening) 15-20 min. before relations. The substance requires time to soften and disperse within the vagina. Other products, such as sponges, gels, foams, and creams can be inserted just prior to relations, as they do not require additional time to soften. Spermicides should not be washed out of the body until a minimum of 6-7 hours have passed since ejaculation. If 2-3 hours elapse between the first and second act of intercourse (and ejaculation), it is necessary to insert another spermicide.
If spermicides are to be used together with other contraceptive methods it is important to check the safety of combining the methods. For example, not all spermicides are recommended for use together with latex products such as diaphragms and cervical caps. If the barrier method is made of silicone rather than latex/rubber, then there should not be a problem.
Note: Oil-based products such as vaseline (petroleum jelly), cooking or aromatic oils, baby oils, should not be inserted into the vagina on a regular basis because they are not vagina-friendly natural substances. They can also cause the rubber in cervical caps or diaphragms to break down faster.
Possible Side Effects of Spermicides
Possible side effects include: irritation, itchiness, burning, or urinary tract, yeast or bacterial infection. Fewer than 5% of women report side effects which lead them to discontinue use.
Advantages and Disadvantages of Spermicides
- Relatively easy to use, although prior experience and skill will increase effectiveness
- Relatively low cost
- Most do not require a doctor’s prescription.
- Chemicals break down and exit the body within a few hours
- Usually no side effects
- Some products require a 15-20 minute waiting period before relations
- Typical effectiveness is less than 85-90%
- In Israel, few high quality products are commercially available, and they are not always easy to find. More effective products may be available with a physician's note or prescription.
Safety of Spermicides
For women concerned about risks of birth defects in children conceived when spermicides were used, a large number of scientific studies have concluded that there is no increased risk of congenital anomalies, altered sex ratio, or early pregnancy loss/miscarriage among spermicide users.
What about Natural Spermicides?
Although many natural forms of spermicides exist in nature and appear in literature throughout human history, there are no modern scientific reviews or efficacy studies to demonstrate their effectiveness.
Note from yoatzot.org editors: As of fall 2017, Vaginal Contraceptive Film (VCF) is increasingly available in Israel. A list of pharmacies that carry VCF can be found at https://www.safevcf.co.il/wheretobuy.
Michal Schonbrun, MPH, CHES, is a women's health educator in Jerusalem. Her areas of expertise include fertility awareness, breast health, and "body literacy" skills. Her website is www.poriutivit.com (click on "English" on the upper left side).