There are two main types of pills
On any given day, roughly 60% of American women of reproductive age (technically defined as 12 to 51) use some form of birth control, ranging from conscious abstinence and condoms to vaginal rings and sterilization. Still, about 50% of annual pregnancies in the U.S. are unplanned.
One of the most common forms of birth control is taking the pill. There are dozens of branded pills available in the U.S. (all upon prescription; there’s no OTC pill), but essentially it all comes down to two categories:
- Progestin-only pills (often referred to as the mini pill)
- Pills that combine progestin with estrogen (combination pills)
The purpose of the progestin is to thicken your mucus — thereby making it harder for sperm cells to travel into your uterus as they get “stuck” in the mucus — and to thin the inside membrane of your uterus. The thinner the uterine lining, the harder it’s for an egg to get embedded there.
Combination pills add estrogen, which provides a third effect: the estrogen blocks ovulation; that means your ovaries do no longer release any eggs. So, not only have sperm cells a harder time reaching the uterus and an egg won’t find a suitable place to implant, but also there now isn’t an egg released in the first place. Obviously, this makes combination pills one of the safest options for birth control, with typical use reducing the chances of an unplanned pregnancy to only 7%. For condoms, it’s about 15%.
Progestin-only pills are equally effective (with a 9% chance of unplanned pregnancy), but for that, they have to be taken at the exact same time every day. So, you can’t take a pill at 8 am today and then again at 2 pm tomorrow. With combination pills, you have a bit more timing flexibility, but also more potential side effects (more on this later).
What are the options for combination pills?
Combination pills are divided into active and inactive pills, which is why a pack of pills often includes pills of different colors. The active pills contain the two hormones and the inactive pills merely are a placebo. Usually, they may just consist of sugar or at best have some vitamins and minerals added. But you are taking the inactive pills in order to maintain your habit of taking a pill a day.
The conventional schedule is 21+7, which is 21 days of active pills, followed by 7 days of inactive pills. There also is a 24+4 scheme. During the “inactive” days you’ll experience menstrual bleeding, but it’s much lighter than it would normally be without birth control medication. This actually is one of the benefits of hormonal birth control: it makes the period much lighter and more regular. There even are extended pill regimes of 84+7 as well as continuous schedules where you no longer have any bleeding at all other than occasional spotting.
Some women skip the inactive pills, starting straight with the next pack. Essentially, this like being on a continuous schedule. Often it’s done out of convenience or sometimes because of medical reasons, such as when treating polycystic ovary syndrome. Skipping the inactive pills generally is considered safe when not done too often, but it’s strongly recommended that you first discuss such a step with your doctor. If indeed suitable for the situation, your doctor may put you on a continuous schedule. Why pay for inactive pills you don’t need?
Aside from the scheduling, the active pills also can be different in strength, i.e., the amount of hormones they contain. So-called monophasic pills have equal amounts of estrogen and progestin. In contrast, multiphasic pills contain varying amounts of each hormone. Therefore, when switching between different brands of combination pills, make sure that the dosage is the same and in line with what your doctor prescribed you.
How are the side effects of progestin-only and combination pills different?
For progestin-only pills, there’s a range of mild to moderate side effects. This includes:
- Breast tenderness & pain (mastalgia)
- Abdominal cramps
- Light to heavy spotting between periods
- Weight gain (~4 lbs in the first year of use on average)
- Depression among adolescent users
- Increased risk of ovarian cysts
- Lower libido
Combination pills naturally include the side effects listed above, since progestin is part of the mix. In addition, other side effects of combination pills are an increased risk of blood clotting and thrombosis. This especially puts women aged 35 and older at greater risk, since with increasing age the blood clotting risk by itself goes up. Therefore, doctors normally prescribe progestin-only pills to women older than 35.
There’s been a decade-long debate about whether birth control pills raise the risk of getting cancer. The scientific record on this question is mixed, but currently, it’s believed that long-term (>5 years) use of hormone-based birth control increases the risks of getting breast cancer and cervical cancer. However, once you discontinue the pill, the risk gradually decreases again with time.
When shouldn’t you take birth control pills?
If any of the following issues apply to you, combination pills won’t work for you, unless your doctor thinks otherwise. In some cases progestin-only pills may still be an option, but not for all. These conditions include:
- Breastfeeding (progestin-only pills are still an option)
- An age of >35, especially when also being a heavy smoker and/or obese (progestin-only pills are a better option)
- History of blood clotting and/or thrombosis
- You just major surgery and won’t be able to move for several weeks
- Kidney, liver or nerve damage
This is by no means a comprehensive list and also doesn’t touch on the contraindications of birth control with other medications and nutritional supplements. It thus is important that you discuss your overall health and any meds you currently are taking with your doctor before starting on birth control.
Grimes, David A., et al. “Progestin-Only Pills for Contraception.” The Cochrane Database of Systematic Reviews, no. 11, 13 Nov. 2013, p. CD007541, www.ncbi.nlm.nih.gov/pubmed/24226383, 10.1002/14651858.CD007541.pub3. Accessed 13 Mar. 2020.
Institute of Medicine (US) Committee on the Relationship Between Oral Contraceptives and Breast Cancer. “Oral Contraceptives and Breast Cancer: A Review of the Epidemiological Evidence with an Emphasis on Younger Women.” Nih.Gov, National Academies Press (US), 2014, www.ncbi.nlm.nih.gov/books/NBK234348/. Accessed 13 Mar. 2020.
Wright, Kristen Page, and Julia V Johnson. “Evaluation of Extended and Continuous Use Oral Contraceptives.” Therapeutics and Clinical Risk Management, vol. 4, no. 5, 2008, pp. 905–11, www.ncbi.nlm.nih.gov/pmc/articles/PMC2621397/. Accessed 13 Mar. 2020.