When the oral contraceptive pill, or "the pill," gained popularity in the 1960s, a sexual revolution was born. Suddenly, women could take control of their own fertility. For the first time, they could have sex with anyone at any time without the fear of pregnancy. And their partner need never know their little secret!

We’ve come a long way since that first pill was sold as a contraceptive in the 1960s. Today, there are many brands available, several types of pills and far fewer serious side effects. In this article, we look at the main birth control pills on the market. Which one's right for you? Here's some information to help you make a more informed decision.

Not Your Mother’s Birth Control

The first contraceptive pills were potent, with between five and 10 times the hormones found in today's birth control pills. There was also just one option, Enovid, and it had serious side effects for women looking for an easy method of birth control. In 1962, just two years after it hit the market, Enovid’s manufacturer was swamped with reports of blood clots. By 1966, the world was abuzz with talk of more side effects including diabetes and cancer.

Lower dose versions of the pill began to compete for Enovid’s business in the late '60s. By 1988, the high-dose pills were removed from the market by America’s Food and Drug Administration (FDA ). The FDA reported that the newer pills were far less likely to cause health problems, including strokes, pelvic inflammatory disease, and iron deficiency anemia. In fact, evidence shows that women taking birth control pills today are even protected from some cancers and cysts. Modern birth control pills are also available in a range of hormone combinations, so women can choose a contraceptive that suits their lifestyle and health concerns, and creates the fewest side effects for their individual bodies.

Monophasic Combination Pills

Monophasic combination pills contain a mix of the hormones estrogen and progesterone. These inexpensive pills control the spike in estrogen levels that usually kick-starts ovulation, thereby suppressing this process and preventing pregnancy. They also thicken the cervical mucus, which acts as a barrier to sperm. As an extra precaution, the pills thin the lining of the uterus. This makes it difficult for any fertilized egg to attach to the womb’s wall.

All of the active pills in the pack contain the same level of hormones. Doctors tend to favor these pills because they’re less confusing than other alternatives, particularly if one is missed. When taken daily at the same time they’re 99 percent effective, although human error sees this number drop to as low as 92 percent. (Read more about how this happens in What causes the birth control pill to fail?)

Women on monophasic pills report lighter, more regular and less painful periods. They also typically see a reduction in other premenstrual symptoms, such as moodiness and bloating. Monophasic pills also reduce the symptoms of acne and endometriosis. In the long term, these pills decrease the risks of ovarian and uterine cancers, pelvic inflammatory disease and cysts on the ovaries and breasts.

As with most drugs, there are some negative side effects too. Some women experience nausea, headaches, dizziness and decreased libido. (For more on that, read Will the birth control pill affect my sex drive?). Birth control pills are also believed to be linked to heart attack, stroke, blood clots, high blood pressure and breast cancer, although these side effects are rare.

Multiphasic Combination Pills

Just like monophasic combination pills, multiphasic combination pills contain a blend of estrogen and progesterone. These pills offer the same three-fold protection as the monophasic combination pills. They’re also just as effective, just as budget-friendly and have similar advantages and side effects.

However, the active multiphasic combination pills do not have the same levels of hormones throughout the month. As a result, they more closely mimic the natural menstrual cycle. In doing so, they’re thought to cause fewer side effects. Women can choose from biphasic combination pills, which contain two different hormones doses, and triphasic pills, which have three.

Mini Pills

Unlike combination pills, mini pills only contain progesterone. This makes them ideal for people who can’t take estrogen, such as breastfeeding women, smokers and anyone with a history of blood clots and high blood pressure. They also thicken the cervical mucus and change the uterine lining, thereby creating hostile conditions for fertilized eggs and sperm. However, they don’t always stop ovulation.

One of the biggest advantages of mini pills is that they’re suitable for everyone. They can also make periods lighter and less painful.

We’re always told to take our pill at the same time every day, but this is even more important with mini pills. They wear off quickly, so even being a few hours late could leave you unprotected. They’re 99 percent effective if taken as prescribed, but many women find this difficult. Mini pills also won’t regulate periods as combination pills do, which can be problematic around vacation time or other special occasions. They also come with a host of possible side effects, including hot flushes, nausea, insomnia and low libido. (Get some libido-boosting tips in 5 Unexpected Ways to Boost Your Sex Drive.)

Emergency Contraceptive Pills

Emergency contraceptive pills, commonly known as morning after pills, differ from the other pills discussed in this article as they’re not a regular form of birth control. Instead, they can prevent pregnancy after an unprotected sexual encounter. They contain hormones that delay or prevent ovulation, or create a hostile environment in the womb.

Generally, a morning after pill must be taken it within three and five days of having unprotected sex. However, the risk of pregnancy increases the longer after sex it’s taken, so if you think you need it, your best bet is to get it right away. The pills decrease the risk of accidental pregnancy by approximately 58-95 percent.

While your baby will not be harmed by the pill if you become pregnant anyway, the morning after pill isn’t without side effects. Some people report nausea, headaches, dizziness and breast tenderness after taking it. (Learn more about emergency contraception in What is the morning after pill and how does it work?)

This Part's Important

It’s important to mention that while the pill guards against pregnancy, it does not protect women from sexually transmitted infections. For this reason, it’s recommended for women in monogamous relationships where both partners have been tested, or as a back-up birth control method used with condoms. (If you're going to use one, do it right! Read 9 Things You Don't Know About Putting On a Condom.)

Overall, women today are pretty lucky. Our mothers may not have had access to birth control, and if they did, it was still pretty scary stuff. Now, birth control is widely accessible, and may even be obtained for free from women's health clinics. More recent statistics from the U.S. Centers for Disease Control show that 82 percent of American women have used oral contraception at some point in their lives. Sex never changes, but thankfully, the world has changed to make it a little safer.

(Get more information about different types of contraception in We Asked an Expert: Which Birth Control Is Best?)