Spermicide | |
---|---|
Background | |
Type | Spermicide |
First use | Ancient |
Failure rates (first year) | |
Perfect use | 6% |
Typical use | 16% [1] |
Usage | |
Reversibility | Immediate |
User reminders | More effective if combined with a barrier method |
Advantages and disadvantages | |
STI protection | No |
Weight gain | No |
Benefits | Provides lubrication |
Spermicide is a contraceptive substance that destroys sperm, inserted vaginally prior to intercourse to prevent pregnancy. As a contraceptive, spermicide may be used alone. However, the pregnancy rate experienced by couples using only spermicide is higher than that of couples using other methods. Usually, spermicides are combined with contraceptive barrier methods such as diaphragms, condoms, cervical caps, and sponges. Combined methods are believed to result in lower pregnancy rates than either method alone. [2]
Spermicides are typically unscented, clear, unflavored, non-staining, and lubricative.
The most common active ingredient of spermicides is nonoxynol-9. Spermicides containing nonoxynol-9 are available in many forms, such as jelly (gel), films, and foams. Used alone, spermicides have a perfect use failure rate of 6% per year when used correctly and consistently, and 16% failure rate per year in typical use. [1]
This list of examples was provided by the Mayo Clinic: [3]
Nonoxynol-9 is the primary chemical in spermicides to inhibit sperm motility. Active secondary spermicidal ingredients can include octoxynol-9, benzalkonium chloride and menfegol. [4] These secondary ingredients are not mainstream in the United States, where nonoxynol-9 alone is typical. Preventing sperm motility will inhibit the sperm from travelling towards the egg moving down the fallopian tubes to the uterus. The deep proper insertion of spermicide should effectively block the cervix so that sperm cannot make it past the cervix to the uterus or the fallopian tubes. A study observing the distribution of spermicide containing nonoxynol-9 in the vaginal tract showed “After 10 min the gel spread within the vaginal canal providing a contiguous covering of the epithelium of variable thickness.” [5] The sole goal of spermicide is to prevent fertilization.
Menfegol is a spermicide manufactured as a foaming tablet. [6] It is available only in Europe.
Octoxynol-9 was previously a common spermicide, but was removed from the U.S. market in 2002 after manufacturers failed to perform new studies required by the FDA. [7]
The spermicides benzalkonium chloride and sodium cholate are used in some contraceptive sponges. [8] Benzalkonium chloride might also be available in Canada as a suppository. [9]
The 2008 Ig Nobel Prize (a parody of the Nobel Prizes) in Chemistry was awarded to Sheree Umpierre, Joseph Hill, and Deborah Anderson, for discovering that Coca-Cola is an effective spermicide, [10] and to C.Y. Hong, C.C. Shieh, P. Wu, and B.N. Chiang for proving it is not. [11] [12]
Lemon juice solutions have been shown to immobilize sperm in the laboratory, [13] as has Krest Bitter Lemon drink. [14] While the authors of the Krest Bitter Lemon study suggested its use as a postcoital douche, this is unlikely to be effective, as sperm begin leaving the ejaculate (out of the reach of any douche) within 1.5 minutes of deposition. No published studies appear to have been done on the effectiveness of lemon juice preparations in preventing pregnancy, though they are advocated by some as 'natural' spermicides. [15]
Lactic acid preparations have also been shown to have some spermicidal effect, and commercial lactic acid-based spermicides are available. [16] [17] A contraceptive containing lactic acid, citric acid, and potassium bitartrate (Phexxi) was approved for use in the United States in May 2020. [18]
Extractives of the neem plant such as neem oil have also been proposed as spermicides based on laboratory studies. [19] Animal studies of creams and pessaries derived from neem have shown they have contraceptive effects; [20] however, trials in humans to determine its effectiveness in preventing pregnancy have not yet been conducted.
Spermicides are believed to increase the contraceptive effectiveness of condoms. [2]
However, condoms that are spermicidally lubricated by the manufacturer have a shorter shelf life [21] and may cause urinary tract infections in women. [22] The World Health Organization says that spermicidally lubricated condoms should no longer be promoted. However, they recommend using a nonoxynol-9 lubricated condom over no condom at all. [23]
Spermicides used alone are only about 91 percent effective. [24] When spermicides are used in conjunction with condoms and other barrier methods there is a 97 percent effective rate for pregnancy prevention.
Temporary local skin irritation involving the vulva, vagina, or penis is the most common problem associated with spermicide use. [25]
Frequent use (two times or more a day) of nonoxynol-9 containing spermicide is inadvisable if STI/HIV exposure is likely, because in this situation there is increased vulvovaginal epithelial disruption and increased risk of HIV acquisition. [25]
In 2007, the United States Food and Drug Administration (FDA) mandated that labels for nonoxynol-9 over-the-counter (OTC) contraceptive products carry a new warning saying they do not protect against STDs and HIV/AIDS. [26] [27]
The first written record of spermicide use is found in the Kahun Papyrus, an Egyptian document dating to 1850 BCE. It described a pessary of crocodile dung and fermented dough. [28] It is believed that the low pH of the dung may have had a spermicidal effect. [29]
Further formulations are found in the Ebers Papyrus from approximately 1500 BCE. It recommended mixing seed wool, acacia, dates and honey, and placing the mixture in the vagina. It probably had some effectiveness, in part as a physical barrier due to the thick, sticky consistency, and also because of the lactic acid (a known spermicide) formed from the acacia. [29]
Writings by Soranus, a 2nd-century Greek physician, contained formulations for a number of acidic concoctions claimed to be spermicidal. His instructions were to soak wool in one of the mixtures, then place near the cervix. [28]
Laboratory testing of substances to see if they inhibited sperm motility began in the 1800s. Modern spermicides nonoxynol-9 and menfegol were developed from this line of research. [28] However, many other substances of dubious contraceptive value were also promoted. Especially after the prohibition of contraception in the U.S. by the 1873 Comstock Act, spermicides—the most popular of which was Lysol—were marketed only as "feminine hygiene" products and were not held to any standard of effectiveness. Worse, many manufacturers recommended using the products as a douche after intercourse, too late to affect all the sperm. Medical estimates during the 1930s placed the pregnancy rate of women using many over-the-counter spermicides at seventy percent per year. [30]
A misconception about spermicides existed in the 1980s and 1990s. A 1988 literature review article noted that in vitro studies of nonoxynol-9 and other spermicides showed inactivation of STI pathogens, including HIV. [31] But a 2002 systemic review and meta-analysis of nine randomized controlled trials of vaginal nonoxynol-9 for HIV and STI prevention involving more than 5,000 women (predominantly sex workers) found no statistically significant reduction in risk of HIV and STIs, but found a small statistically significant increase in genital lesions among nonoxynol-9 spermicide users. [32] And in a high-risk population using a nonoxynol-9 vaginal gel more than three applications per day on average, the risk of HIV acquisition was increased. [25]
A condom is a sheath-shaped barrier device used during sexual intercourse to reduce the probability of pregnancy or a sexually transmitted infection (STI). There are both external condoms, also called male condoms, and internal (female) condoms.
Safe sex is sexual activity using methods or contraceptive devices to reduce the risk of transmitting or acquiring sexually transmitted infections (STIs), especially HIV. "Safe sex" is also sometimes referred to as safer sex or protected sex to indicate that some safe sex practices do not eliminate STI risks. It is also sometimes used colloquially to describe methods aimed at preventing pregnancy that may or may not also lower STI risks.
The diaphragm is a barrier method of birth control. It is moderately effective, with a one-year failure rate of around 12% with typical use. It is placed over the cervix with spermicide before sex and left in place for at least six hours after sex. Fitting by a healthcare provider is generally required.
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.
The cervical cap is a form of barrier contraception. A cervical cap fits over the cervix and blocks sperm from entering the uterus through the external orifice of the uterus, called the os.
Microbicides for sexually transmitted infections are pharmacologic agents and chemical substances that are capable of killing or destroying certain microorganisms that commonly cause sexually transmitted infection.
Benzalkonium chloride, also known as alkyldimethylbenzylammonium chloride (ADBAC) and by the trade name Zephiran, is a type of cationic surfactant. It is an organic salt classified as a quaternary ammonium compound. ADBACs have three main categories of use: as a biocide, a cationic surfactant, and a phase transfer agent. ADBACs are a mixture of alkylbenzyldimethylammonium chlorides, in which the alkyl group has various even-numbered alkyl chain lengths.
Personal lubricants are specialized lubricants used during sexual acts, such as intercourse and masturbation, to reduce friction to or between the penis and vagina, anus or other body parts or applied to sex toys to reduce friction or to ease penetration. As of 2015, the personal lubricant market was estimated to be worth at least $400 million.
The contraceptive sponge combines barrier and spermicidal methods to prevent conception. Sponges work in two ways. First, the sponge is inserted into the vagina, so it can cover the cervix and prevent any sperm from entering the uterus. Secondly, the sponge contains spermicide.
Male contraceptives, also known as male birth control, are methods of preventing pregnancy by interrupting the function of sperm. The main forms of male contraception available today are condoms, vasectomy, and withdrawal, which together represented 20% of global contraceptive use in 2019. New forms of male contraception are in clinical and preclinical stages of research and development, but as of 2024, none have reached regulatory approval for widespread use.
There are many methods of birth control that vary in requirements, side effects, and effectiveness. As the technology, education, and awareness about contraception has evolved, new contraception methods have been theorized and put in application. Although no method of birth control is ideal for every user, some methods remain more effective, affordable or intrusive than others. Outlined here are the different types of barrier methods, hormonal methods, various methods including spermicides, emergency contraceptives, and surgical methods and a comparison between them.
A female condom is a barrier device that is used during sexual intercourse as a barrier contraceptive to reduce the probability of pregnancy or sexually transmitted infection (STI). It is inserted in the vagina before intercourse to reduce the risk of exposure to semen or other body fluids. The female condom was invented in 1990 by Danish MD Lasse Hessel, and approved for sale in the US by the FDA in 1993. It was developed as an alternative to the older external condom, which is put on the man.
Birth control, also known as contraception, anticonception, and fertility control, is the use of methods or devices to prevent pregnancy. Birth control has been used since ancient times, but effective and safe methods of birth control only became available in the 20th century. Planning, making available, and using human birth control is called family planning. Some cultures limit or discourage access to birth control because they consider it to be morally, religiously, or politically undesirable.
An intrauterine device (IUD), also known as an intrauterine contraceptive device or coil, is a small, often T-shaped birth control device that is inserted into the uterus to prevent pregnancy. IUDs are a form of long-acting reversible contraception (LARC).
Intravaginal administration is a route of administration where the substance is applied inside the vagina. Pharmacologically, it has the potential advantage to result in effects primarily in the vagina or nearby structures with limited systemic adverse effects compared to other routes of administration.
CONRAD is a non-profit scientific research organization that works to improve global and reproductive health, particularly in women in developing countries. CONRAD was established in 1986 under a cooperative agreement between Eastern Virginia Medical School (EVMS) and the United States Agency for International Development (USAID). CONRAD’s products are developed primarily for women in low-resource settings, in that they are designed to be safe, affordable and user-friendly. CONRAD is led by Scientific and Executive Director Gustavo F. Doncel, M.D., Ph.D. Primary funding for CONRAD comes from the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) through the U.S. Agency for International Development (USAID), with additional funding from The Bill & Melinda Gates Foundation and the National Institutes of Health (NIH).
Birth control in the United States is available in many forms. Some of the forms available at drugstores and some retail stores are male condoms, female condoms, sponges, spermicides, over-the-counter progestin-only contraceptive pills, and over-the-counter emergency contraception. Forms available at pharmacies with a doctor's prescription or at doctor's offices are oral contraceptive pills, patches, vaginal rings, diaphragms, shots/injections, cervical caps, implantable rods, and intrauterine devices (IUDs). Sterilization procedures, including tubal ligations and vasectomies, are also performed.
A vaginal microbicide is a microbicide for vaginal use, generally as protection against the contraction of a sexually transmitted infection during vaginal sexual intercourse. Vaginal microbicides are topical gels or creams inserted into the vagina.
Multipurpose prevention technologies (MPTs) are a class of products designed to address at least two health issues simultaneously, often focusing on sexual and reproductive health which includes contraception, human immunodeficiency virus (HIV) prevention, other sexually transmitted infection (STI) preventions, such as genital infection by human simplex virus (HSV) infection and human papillomavirus (HPV) infection. For example, MPTs can combine contraception and HIV prevention, contraception and other STI prevention, or the prevention of multiple STIs. Since the simultaneous use of multiple products with a single indication against each specific sexual and reproductive health issue is inconvenient, this method may affect adherence. As a result, the goal of developing a MPT as an all-in-one product is to combat this issue.
Lactic acid/citric acid/potassium bitartrate, sold under the brand name Phexxi, is a non-hormonal combination medication used as a method of birth control. It contains lactic acid, citric acid, and potassium bitartrate. It is a gel inserted into the vagina.
Currently available spermicides containing nonoxynol-9 are ineffective as microbicides, in particular as HIV-preventive measures.17 Thus, spermicides used alone are not recommended to prevent HIV or other STIs. Furthermore, frequent use (more than 2 times a day) of spermicide causes more vulvovovaginal epithelial disruption,18 which theoretically could increase susceptibility to HIV. In a high-risk population using a vaginal gel with nonoxynol-9 more than three applications per day on average, the risk of HIV acquisition was increased compared with placebo.19p.399–400:
Disadvantages and cautionsp. 401:
Local irritation
Temporary skin irritation involving the vulva, vagina, or penis caused by either local toxicity or allergy to the formulation is the most common problem associated with spermicide use... Although vaginal epithelial disruption has been associated with frequent use (twice a day or more) of spermicides containing N-9, this is usually asymptomatic. In a low risk population, long-term use of N-9 containing methods was not associated with epithelial disruption.22
N-9 spermicides are inadvisable if STI/HIV exposure is likely in situations that would involve frequent use defined as 2 times or more a day.