There are many methods of birth control (or contraception) 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.

While many methods may prevent conception, only male and female condoms are effective in preventing sexually transmitted infections.

Methods

Hormonal methods

The IUD (intrauterine device) is a T-shaped device that is inserted into the uterus by a trained medical professional. There are two different types of IUDs: copper or hormonal. The copper IUD (also known as a copper T intrauterine device) is a non-hormonal option of birth control. It is wrapped in copper which creates a toxic environment for sperm and eggs, thus preventing pregnancy. The failure rate of a copper IUD is approximately 0.8% and can prevent pregnancy for up to 10 years. The hormonal IUD (also known as levonorgestrel intrauterine system or LNg IUD) releases a small amount of the hormone called progestin that can prevent pregnancy for 3–8 years with a failure rate of 0.1-0.4%. IUDs can be removed by a trained medical professional at any time before the expiration date to allow for pregnancy.

Oral contraceptives are another option, these are commonly known as 'the pill'. These must be taken at the same time every day in order to be the most effective. There are two different options, there is a combined pill that contains both of the hormones estrogen and progestin, and a progestin-only pill. The failure rate of each of these oral contraceptives is 7%.

Some choose to get an injection or a shot in order to prevent pregnancy. This is an option where a medical professional will inject the hormone progestin into a woman's arm or buttocks every 3 months to prevent pregnancy. The failure rate is 4%.

Women can also get an implant into their upper arm that releases small amounts of hormones to prevent pregnancy. The implant is a thin rod-shaped device that contains the hormone progestin that is inserted into the upper arm and can prevent pregnancy for up to 3 years. The failure rate for this method is 0.1%.

The patch is another simple option; it is a skin patch containing the hormones progestin and estrogen that is absorbed into the bloodstream preventing pregnancy. The patch is typically worn on the lower abdomen and replaced once a week. The failure rate for this is 7%.

The hormonal vaginal contraceptive ring is a ring that contains the hormones progestin and estrogen that a woman inserts into the vagina. It is replaced once a month and has a failure rate of 7%.

Barrier methods

The male condom is typically made of latex (but other materials are available, such as lambskin, if either partner has a latex allergy). The male condom is placed over the male's penis and prevents the sperm and semen from entering the partner's body. It can prevent pregnancy, and STIs such as, but not limited to, HIV if used appropriately. Male condoms are disposable (each condom can only be used once) and are easily accessible at local stores in most countries. Condoms have a failure rate of 2% when used correctly during every act of intercourse, and 13% when used 'typically', which includes cases where they are used inconsistently or incorrectly.

The diaphragm or cervical cap is a small shallow cup-like cap that is inserted into the vagina with spermicide to cover the cervix and block sperm from entering the uterus. It is inserted before sexual intercourse and comes in different sizes. It needs to be fitted by a medical professional. It has a failure rate of 17%.

A contraceptive sponge is another contraceptive method Like the diaphragm, the contraceptive sponge contains spermicide and is inserted into the vagina and placed over the cervix to prevent sperm from entering the uterus. The sponge must be kept in place 6 hours after sexual intercourse before it can be removed and discarded. The failure rate for women who have had a baby before is 27%; for those who have not had a baby, the failure rate is 14%.

The female condom is worn by the woman; it is inserted into the vagina and prevents the sperm from entering her body. It can help prevent STIs and can be inserted up to 8 hours before intercourse. The failure rate is 21%.

Other methods

Spermicides come in various forms such as: gels, foams, creams, film, suppositories, or tablets. The spermicides create an environment in which sperm can no longer live. Though typically used in addition to the male condom, diaphragm, or cervical cap, they can also be used by themselves. They are put into the vagina no more than an hour before intercourse and kept inside the vagina for 6–8 hours after intercourse. The failure rate is 21%.

In the fertility awareness-based method a woman who has a predictable and consistent menstrual cycle tracks the days that she is fertile. The typical woman has approximately 9 fertile days a month and either avoids intercourse on those days or uses an alternative birth control method for that period of time. The failure rate is between 2-23%.

Lactational amenorrhea (LAM) is an option for women who have had a baby within the past 6 months and are breastfeeding. This method is only successful if it has been less than 6 months since the birth of the baby, they must be fully breastfeeding their baby, and not having any periods. The method is almost as effective as an oral contraceptive if the 3 conditions are strictly followed.

The 'pull out method' or coitus interruptus is a method where the male will remove his penis from the vagina before ejaculating; this prevents sperm from reaching the egg and can prevent pregnancy. This method has to be done correctly every time and is best if used in addition to other forms of birth control. It has a failure rate of approximately 22%.

Emergency contraceptives

A copper IUD can be used as an emergency contraceptive as long as it is inserted within 5 days after intercourse.

There are two different types of emergency contraceptive pills. One contains levonorgestrel and can prevent pregnancy if taken within 3 days of intercourse. The other contains ulipristal acetate and can prevent pregnancy if taken within 5 days of intercourse. This option can be used if other birth control methods fail.

Use of an emergency contraceptive should occur as soon as possible after unprotected sexual intercourse to reduce the chance of pregnancy.

Surgical methods

Tubal ligation is also known as 'tying tubes'. This is the surgical process where medical professional closes or ties the fallopian tubes in order to prevent sperm from reaching the eggs. This is often done as an outpatient surgical procedure and is effective immediately after it is performed. The failure rate is 0.5%.

A vasectomy is a minor surgical procedure where a doctor will cut the vas deferens and seal the ends to prevent sperm from reaching the penis and ultimately the egg. The method is usually successful after 12 weeks post-procedure or when the sperm count is zero. The failure rate is 0.15%.

User dependence Different methods require different levels of diligence by users. Methods with little or nothing to do or remember, or that require a clinic visit less than once per year are said to be non-user dependent, forgettable, or top-tier methods. Intrauterine methods, implants, and sterilization fall into this category. For methods that are not user dependent, the actual and perfect-use failure rates are very similar.

Many hormonal methods of birth control, and LAM require a moderate level of thoughtfulness. For many hormonal methods, clinic visits must be made every three months to a year to renew the prescription. The pill must be taken every day, the patch must be reapplied weekly, or the ring must be replaced monthly. Injections are required every 12 weeks. The rules for LAM must be followed every day. Both LAM and hormonal methods provide a reduced level of protection against pregnancy if they are occasionally used incorrectly (rarely going longer than 4–6 hours between breastfeeds, a late pill or injection, or forgetting to replace a patch or ring on time). The actual failure rates for LAM and hormonal methods are somewhat higher than the perfect-use failure rates.

Higher levels of user commitment are required for other methods. Barrier methods, coitus interruptus, and spermicides must be used at every act of intercourse. Fertility awareness-based methods may require daily tracking of the menstrual cycle. The actual failure rates for these methods may be much higher than the perfect-use failure rates.

Side effects Different forms of birth control have different potential side effects. Not all, or even most, users will experience side effects from a method. The less effective the method, the greater the risk of pregnancy, and the side effects associated with pregnancy.

Minimal or no side effects occur with coitus interruptus, fertility awareness-based, and LAM. Some forms of periodic abstinence encourage examination of the cervix; insertion of the fingers into the vagina to perform this examination may cause changes in the vaginal environment. Following the rules for LAM may delay a woman's first post-partum menstruation beyond what would be expected from different breastfeeding practices.

Barrier methods have a risk of allergic reactions. Users sensitive to latex may use barriers made of less allergenic materials - polyurethane condoms, or silicone diaphragms, for example. Barrier methods are also often combined with spermicides, which have possible side effects of genital irritation, vaginal infection, and urinary tract infection.

Sterilization procedures are generally considered to have a low risk of side effects, though some persons and organizations disagree. Female sterilization is a more significant operation than vasectomy, and has greater risks; in industrialized nations, mortality is 4 per 100,000 tubal ligations, versus 0.1 per 100,000 vasectomies.

After IUD insertion, users may experience irregular periods in the first 3–6 months with Mirena, and sometimes heavier periods and worse menstrual cramps with ParaGard. However, continuation rates are much higher with IUDs compared to non-long-acting methods. A positive characteristic of IUDs is that fertility and the ability to become pregnant returns quickly once the IUD is removed.

Because of their systemic nature, hormonal methods have the largest number of possible side effects. Combined hormonal contraceptives contain estrogen and progestin hormones. They can come in formulations such as pills, vaginal rings, and transdermal patches. Most people who use combined hormonal contraception experience breakthrough bleeding within the first 3 months. Other common side effects include headaches, breast tenderness, and changes in mood. Side effects from hormonal contraceptives typically disappear over time (3-5 months) with consistent use. Less common effects of combined hormonal contraceptives include increasing the risk of deep vein thrombosis to 2-10 per 10,000 women per year and venous thrombotic events (see venous thrombosis) to 7-10 per 10,000 women per year.