Whether you’re currently on birth control, considering going on birth control, or trying to get off, here are the facts to be aware of —and the side effects you’ll find on the fine print of birth control pamphlets.
When birth control pills first came out in the 1960’s, it was a game-changer for women as it gave them a simple way to put them in the driver’s seat for birth control. By enabling women to better determine when or if they have children, oral contraceptives and other methods of reliable birth control have helped make it possible for more women to pursue higher education, enter advanced professional fields and earn higher wages.
But over the years we’ve learned that there is no such thing as a free ride. Just like with every other medication, there are side effects, both major and minor associated with the pill. With roughly 10 million women in the US taking birth control pills at any given time, and 1 in 4 girls 15-24 years old using it, even uncommon adverse events aren’t all that rare. (1)
To decide what’s best for you, it’s important to know what some of the potential side effects are and what your non-hormonal options are today.
What is the birth control pill?
The birth control pill most commonly consists of a combination of synthetic estrogen and progesterone (though also comes in a form made of progesterone only). The FDA first approved it as a form of birth control in 1960, and since then scientists realized that it could be equally effective with fewer serious side effects if they used much lower doses of these hormones. (2) The main way it works is by inhibiting ovulation (ie, stopping the ovary from spewing an egg into the fallopian tube each month).
The good news is that when taken correctly, meaning no missed doses, it is extremely effective at preventing pregnancy, with fewer than 1 pregnancy for every 100 users each year. In reality, women do forget doses, and there are about 9 pregnancies per 100 users per year. (2)
Hormonal birth control side effects.
If you look at the package insert of a typical oral contraceptive pill (OCP), there are a number of less serious ‘adverse reactions’ women might get. Here is a sampling of the over 20 listed on one popular brand (3).
Adverse reactions of the birth control pill:
- Abdominal cramps and bloating
- Edema (water retention)
- Melasma (dark pigmentation on the face) which may persist
- Mental depression
- Reduced tolerance to carbohydrates (insulin resistance)
- Change in corneal curvature (steepening)
- Vaginal candidiasis
Some of these side effects are temporary, lasting just a few months, and others are minor enough, such as mild insulin resistance, that it’s not clear how much they impact long-term health. However, there are several more serious side effects that deserve more attention.
Vaginal candidiasis is particularly noteworthy and concerning because in recent years it has become increasingly clear that all those bugs in the human microbiome play a critical part in health and immunity, and they are easily upended by various medications. Antibiotics are an obvious culprit, but it turns out that birth control can also play a role. Studies of women on birth control show that bacterial vaginosis is less frequent, but vaginal candidiasis occurs more often.
Gum disease and croHn’s disease
Periodontitis, gum disease, is also more common, maybe because the Candida and Prevotella species that contribute to it are more abundant in the mouth when taking birth control. Crohn’s disease, a form of inflammatory bowel disease, also occurs more often in women on birth control, perhaps almost three times as often. This may be a result of the change in gut microbes and estrogen’s negative impact on gut permeability. (4)
mental health and depression
In one randomized controlled study of 178 women, those on birth control experienced less premenstrual depression but during other parts of their cycle were more likely to be anxious and moody. (5) In an observational study of over 1 million women in Denmark, researchers compared women who chose to take the pill with those who didn’t. They found that the women who took the pill with both estrogen and progesterone were about 20% more likely to end up on an anti-depressant, and teenagers were 80% more likely. (6) There may even be an impact on cognitive function. According to one small study of 43 women, those on OCPs had worse verbal fluency than those not taking hormones. (7)
Additionally, though not listed on the package insert, there is some concern that various vitamins and minerals are depleted in OCP users. (8) Studies have found lower levels of numerous vitamins (folate, B2, B6, B12, vitamins C and E) and minerals (selenium, zinc, and magnesium) in women taking oral contraceptives.
The recommendation from this review article is to take a multivitamin/multimineral if you are on an OCP. But there is concern that these deficiencies represent just the nutrients scientists have thought to test and that the pill could also be affecting other nutrient levels as well that you won’t find in a multivitamin/multimineral.
Inflammation, which is a common denominator in essentially all chronic disease, is also more likely with OCPs. High sensitivity c-reactive protein, a measure of inflammation that we check routinely at Parsley Health, has been shown to be high much more often among OCP users than non-users, perhaps helping to also explain the increased risk for cardiovascular events with OCPs.(9)
Then there are the most serious adverse reactions, with venous thrombosis being one of the more common ones. This is a blood clot that forms in the vein and has the potential to travel to the lungs and become life-threatening. In a year, only about 2-4 out of 10,000 women will develop this kind of blood clot. But for those taking OCPs, the risk increases about 3.5 times. (10) The risk of a heart attack or stroke in women under 45 years old is also very uncommon. Nevertheless, OCP’s increase that risk by 60% at the lowest estrogen dose, and more so as the estrogen dose increases. (11)
A more common problem, though less likely to be life-threatening, is gallstones. About 5% of women under the age of 40 have gallstones (12), but since estrogen and progesterone increase gallstone formation, taking OCPs makes the likelihood of developing gallstones 35-50% higher for women who do take OCPs compared to women who don’t.(13,14) Having gallstones becomes a significant quality of life and health issue, as gallstones can be painful and lead to surgery to remove the gallbladder. Ultimately this has a negative and life-long impact on digestion and that ever-important microbiome.
Another major concern is cancer. In fact, OCP’s do decrease risk for ovarian cancer by about 30-50% and endometrial cancers by 30%, but they also increase the risk of breast cancer by an estimated 20% and cervical cancer by 10-200%, depending on the length of use. In the end, this cost/benefit may be a wash, but if you know you are at risk of one or the other, that should factor into your decision about taking it. (16)
Decreased sex drive
Another issue with the pill and this is the ultimate irony, is that though it frees you up to have sex without worry of pregnancy, for a small percentage of women, it also significantly diminishes sex drive. (17) A likely explanation is that OCPs decrease the amount of testosterone circulating in your body. (18)
The benefits of the birth control pill.
Besides being an effective means for birth control and decreasing risk for ovarian and endometrial cancers, there are other potential upsides to OCPs, such as lighter and less painful periods, more regular periods and less acne (with some forms of OCPs).
Often doctors will prescribe the pill to address symptoms such as painful periods, acne, migraines, and excessive hair growth, but at Parsley Health we aim to address the underlying causes. Once we do that, it frees our patients up to pick the contraceptive method that best meets their needs, and perhaps one without as many side effects.
Final thoughts on the birth control pill.
For some girls and women, there are individual and personal reasons that make OCPs the best choice of birth control for them. But the above information makes it clear that the decision to start or continue using OCPs is a serious one with many potential short and long-term effects. It deserves thoughtful consideration by the patient and the doctor before choosing it. And for those who decide they don’t want to increase their risk for these diseases, there are other birth control options, including condoms, non-hormonal copper IUDs, diaphragms and various types of fertility trackers.
It is wonderful that women have these choices for birth control. I hope this information not only keeps you in the driver’s seat for contraception but also helps you know where you are going.
- Khalili H, Risk of Inflammatory Bowel Disease with Oral Contraceptives and Menopausal Hormone Therapy: Current Evidence and Future Directions. Drug Saf. 2016 Mar;39(3):193-7.
- Lundin C, Danielsson KG, Bixo M, et al. Combined oral contraceptive use is associated with both improvement and worsening of mood in the different phases of the treatment cycle-A double-blind, placebo-controlled randomized trial. Psychoneuroendocrinology. 2017 Feb;76:135-143.
- Skovlund CW, Morch LS, Kessing LV, etal. Association of Hormonal Contraception With Depression. JAMA Psychiatry. 2016;73(11):1154-1162.
- Griksiene R1, Ruksenas O. Effects of hormonal contraceptives on mental rotation and verbal fluency. Psychoneuroendocrinology. 2011 Sep;36(8):1239-48.
- Palmery M, Saraceno A, Vaiarelli A, Carlomagno G, Oral contraceptives and changes in nutritional requirements. Eur Rev Med Pharmacol Sci. 2013; 17: 1804-1813.
- Cauci S1, Di Santolo M, Culhane JF, et al. Effects of third-generation oral contraceptives on high-sensitivity C-reactive protein and homocysteine in young women. Obstet Gynecol. 2008 Apr;111(4):857-64.
- de Bastos M, Stegeman BH, Rosendaal FR, etal. Combined oral contraceptives: venous thrombosis. Cochrane Database Syst Rev. 2014 Mar 3;(3):CD010813.
- Roach RE.J., Helmerhorst FM, Lijfering WM., Et al. Combined oral contraceptives: the risk of myocardial infarction and ischemic stroke. Cochrane Database of Systematic Reviews, http://cochranelibrary-wiley.com/doi/10.1002/14651858.CD011054.pub2/abstract
- Everhart JE, Khare M, Hill M, Maurer KR. Prevalence and ethnic differences in gallbladder disease in the United States. Gastroenterology. 1999; 117:632–639.
- Thijs C, Knipschild P. Oral contraceptives and the risk of gallbladder disease: a meta-analysis. Am J Public Health 1993;83:1113–20.
- Grodstein F, Colditz GA, Hunter DJ, et al. A prospective study of symptomatic gallstones in women: relation with oral contraceptives and other risk factors. Obstet Gynecol 1994;84:207–14.
- Hage FG, Mansure SJ, Xing D, Oparil S. Hypertension in women. Kidney Int Suppl (2011). 2013 Dec; 3(4): 352–356.
- Burrows LJ1, Basha M, Goldstein AT. The effects of hormonal contraceptives on female sexuality: a review. J Sex Med. 2012 Sep;9(9):2213-23.
- Zimmerman Y, Eijkemans MJ, Coelingh Bennink HJ, etal. The effect of combined oral contraception on testosterone levels in healthy women: a systematic review and meta-analysis. Human Reproduction Update 2014; 20(1): 76-105.