Are you thinking of taking birth control pills? Birth control pills are some of the most used contraceptives. That's because they work well and they're easy to use. But there are a lot of choices.

How do you know which to choose? Here's a breakdown of birth control pill types to make it easier to know your choices.

There are two main kinds of birth control pills:

• Combination birth control pills. This type of pill has both estrogen and progestin. There are many combination pills to choose from. Your choice depends on how often you want to have periods and the dose of hormones that is best for you.
• Progestin-only pills. Also called minipills, this type of pill has progestin only. The progestin-only pill doesn't offer as many choices as combination pills. In each pack of pills, all the pills have the same amount of progestin and all the pills are active.

Combination birth control pills come in different mixtures of pills that have hormones, called active pills, and pills that don't have hormones, called inactive pills. The mix you choose depends on how often you want to have periods:

• Conventional. Conventional packs most often have 21 active pills and seven inactive pills, or 24 active pills and four pills that aren't active. You bleed every month when you take the inactive pills.
• Continuous use or extended use. These packs most often have 84 active pills and seven pills that aren't active. You bleed only four times a year, when you take the inactive pills. If you don't want any bleeding, you can choose a pill type that has only active pills or you can skip the pills that aren't active in each pack.

The dose of hormones in the active pills in combination birth control pills either stays the same or changes:

• Monophasic. In this type of combination birth control pill, each active pill has the same amounts of estrogen and progestin.
• Multiphasic. In this type of combination birth control pill, the amounts of hormones in the active pills vary.

Most combination birth control pills have 10 to 35 micrograms of ethinyl estradiol, a kind of estrogen. People who are sensitive to hormones may want to take one of the pills with a lower dose of estrogen. But low-dose pills may cause more bleeding or spotting between periods than higher dose pills. This is called breakthrough bleeding.

The Food and Drug Administration (FDA) recently approved the first birth control pill you can get without a prescription. It's a progestin-only pill that the FDA first approved for prescription use only, then switched to being one you can get without a prescription.

For other types of birth control pills, including combination birth control pills, you need a prescription from a healthcare professional.

Combination birth control pills prevent the ovaries from releasing an egg. They also slow an egg's progress through the fallopian tubes, thicken cervical mucus and thin the lining of the uterus, called the endometrium. All these actions help keep sperm from joining the egg.

Progestin-only pills also slow an egg's progress through the fallopian tubes, thicken cervical mucus and thin the lining of the uterus to help keep sperm from reaching the egg. Some types of these pills also may keep the ovary from releasing an egg, called ovulation.

No. Your healthcare professional needs to know about your medical history and any medicines you take to find which birth control pill is right for you.

Your healthcare professional may tell you not to use combination birth control pills if you:

• Have just given birth.
• Are older than age 35 and smoke.
• Have poorly controlled high blood pressure.
• Have a blood clotting disorder or a history of deep vein thrombosis or pulmonary embolism.
• Have had or have breast cancer.
• Have had a stroke or heart disease.
• Have diabetes-related complications.
• Have a liver or gallbladder condition.
• Have lupus.
• Have a history of migraine with aura.
• Have uterine bleeding with no known cause.
• Will have limited movement for a long time due to major surgery.
• Take St. John's wort, or medicines to prevent convulsions or tuberculosis.
• Had gastric bypass surgery.

Your healthcare professional may tell you not to use the progestin-only pill if you:

• Had or have breast cancer.
• Have certain liver conditions.
• Have uterine bleeding with no known cause.
• Take medicines to prevent convulsions or tuberculosis.
• Had gastric bypass surgery.
• Have some forms of lupus.

Pros

Here are some possible benefits of combination birth control pills:

• Easy to stop if you want to get pregnant.
• Relief from premenstrual syndrome, also called PMS.
• Menstrual cramps, called dysmenorrhea, that aren't as bad.
• Some relief of acne.
• Shorter, lighter periods that you can predict, or fewer or no periods.
• Less heavy bleeding, called menorrhagia, and related anemia.
• Fewer symptoms of endometriosis.
• Lower risk of ovarian, endometrial and colorectal cancers.
• Might help bone health.
• Less unwanted hair growth, called hirsutism, caused by polycystic ovary syndrome.

Cons

Here are some possible drawbacks of combination birth control pills:

• Skipping pills or taking them late may affect how well they work.
• Don't protect against sexually transmitted infections.
• Higher risk of high cholesterol, heart attack and stroke.
• Higher risk of blood clots. The risk is higher for people who smoke and people older than 35 years of age. Pills that have higher doses of estrogen have been linked to a slightly greater risk of blood clots.
• Higher risk of cervical cancer and breast cancer for people while they take combined birth control pills. But this risk seems to go down little by little after the pills are stopped.
• Side effects may include irregular bleeding, bloating, breast tenderness, nausea, depression, weight gain and headache.

Pros

Here are some possible benefits of progestin-only birth control pills:

• Easy to stop if you want to get pregnant.
• Can be used right after giving birth or having a miscarriage or abortion.
• People with certain health problems such as blood clots, migraines, high blood pressure or a high risk of heart disease can take them. Combined pills raise those risks.
• Are less likely than combined pills to affect breastfeeding.
• Less risk of endometrial cancer.

Cons

Here are some possible drawbacks of progestin-only birth control pills:

• Must be taken at the same time every day. If you skip a pill or take a pill more than three hours late, you need to use a backup form of birth control for at least two days.
• Don't protect against sexually transmitted infections.
• Side effects may include irregular menstrual bleeding, ovarian cysts, less sex drive, headache, breast tenderness, acne, weight gain, depression and hirsutism.
• Slightly higher risk that if pregnancy happens, the fertilized egg will implant outside the uterus. This is called an ectopic pregnancy.

You have many choices for birth control. If you want to take birth control pills, work with your healthcare professional to decide which type of birth control pill is right for you.

Combination birth control pills prevent your ovaries from releasing an egg. They also slow an egg's progress through the fallopian tubes, thicken cervical mucus and thin the lining of the uterus (endometrium). All of these actions help keep sperm from joining the egg.

The minipill slows an egg's progress through the fallopian tubes, thickens cervical mucus and thins the endometrium — all of which help prevent sperm from reaching the egg. The minipill sometimes also suppresses ovulation.

No. Your doctor will ask about your medical history and any medications you take to determine which birth control pill is right for you.

Your doctor may discourage use of combination birth control pills if you:

• Have just given birth
• Are older than age 35 and smoke
• Have poorly controlled high blood pressure
• Have a blood clotting disorder or a history of deep vein thrombosis or pulmonary embolism
• Have a history of breast cancer
• Have a history of stroke or heart disease
• Have diabetes-related complications
• Have liver or gallbladder disease
• Have a history of migraines with aura
• Have unexplained uterine bleeding
• Will be immobilized for a prolonged period due to major surgery
• Take St. John's wort, or anticonvulsant or anti-tuberculous agents

Your doctor may discourage use of the minipill if you:

• Have breast cancer
• Have certain liver diseases
• Have unexplained uterine bleeding
• Take anticonvulsant or anti-tuberculous agents

Pros

• Easily reversed method of birth control if you hope to get pregnant
• Relief from premenstrual syndrome (PMS)
• Less severe menstrual cramps (dysmenorrhea)
• Improvement in acne
• Shorter, lighter and more predictable periods, or fewer or no periods
• Reduction in heavy bleeding (menorrhagia) and related anemia
• Reduced symptoms of endometriosis
• Lowered risk of ovarian, endometrial and colorectal cancers
• Possible positive effect on bone mineral density
• Improvement in unwanted hair growth (hirsutism) caused by polycystic ovary syndrome

Cons

• Skipping pills or taking them late may reduce effectiveness
• No protection against sexually transmitted infections, including HIV
• Increased risk of high cholesterol, heart attack and stroke
• Increased risk of blood clots, especially for smokers and women older than 35 years of age, with a slightly greater risk of blood clots linked to pills that contain higher doses of estrogen
• Increased risk of cervical cancer and breast cancer for women who are currently taking combined birth control pills, but this risk appears to gradually decline to normal levels once you stop taking the pills
• Side effects such as irregular bleeding, bloating, breast tenderness, nausea, depression, weight gain and headache

Pros

• Easily reversed method of birth control if you hope to get pregnant
• Can be taken even if you have certain health problems that increase the risks of taking combined pills, such as blood clots, migraines, high blood pressure or a high risk of heart disease
• Are less likely than combined pills to interfere with breast-feeding
• Lowered risk of endometrial cancer

Cons

• Must be taken at the same time every day — if you skip a pill or take a pill more than 3 hours late, you need to use a backup form of birth control for at least two days
• No protection against sexually transmitted infections, including HIV
• Side effects such as irregular menstrual bleeding, ovarian cysts, decreased libido, headache, breast tenderness, acne, weight gain, depression and hirsutism
• Slightly increased risk that if pregnancy occurs, the fertilized egg will implant outside the uterus (ectopic pregnancy)

You have many options for birth control. If you choose to take birth control pills, work with your doctor or other care provider to decide which type of birth control pill is right for you.