I started working on No Period. Now What? August 6 2012. The first year or so I worked on putting together the survey, getting it out to respondents. The second year consisted of research and writing, the third was editing, and the last six months doing book design and copy editing. That means the research we refer to was mostly published in 2014 or earlier. Additional information has become available since then and I plan to check in on different topics to ensure that our recommendations remain valid.
We put together an information sheet on birth control pills, periods, and what to expect; enter your email address to download the guide.
One question I wanted to reexamine as I put together the info sheet was whether there is additional evidence on the effects of birth control pills/oral contraceptive pills (OCP) on bone density. When I was researching for the book, the consensus I found was that OCP seemed to prevent further bone loss in a woman with hypothalamic amenorrhea, but increases in bone density and strength were unlikely. The best way to increase bone density was through weight gain and period restoration.
There are quite a few articles that have been published in the last two years, generally agreeing with my conclusions. As these are recent papers the full texts tend not to be freely available but I feel comfortable using the abstracts for this overview as it was simply to confirm the recommendations and research from the book. If there are any other articles you think we should be aware of or you’d like us to review, please let us know!
I investigated five recent articles, listed below (as well as reading through other abstracts). The first was one of the larger studies I’ve seen, looking at bone density in 826 normally cycling teenagers. Those not using birth control pills had an average 2.5% increase in bone density over the course of a year, versus a 1.45% increase in those on the pill. This illustrates that this formulation of the pill was actually interfering with normal bone growth. A similar but small study found an increase of 2.0% in bone density in teenagers on birth control pills versus 12.2% in non-users.
Agreeing with our assertions in No Period. Now What? a study in 91 women in the armed forces found that the pill essentially had no impact on bone density; weight loss decreased density, whereas weight gain, normal menstrual cycles, and a normal Eating Disorder Inventory score were associated with increased bone density.
A couple of the studies were reviews, similarly agreeing with our conclusions. The major finding by Lebow et al. was that the majority of studies found no benefit of estrogen therapies on bone density. Finally, Bergstrom et al. go even further, arguing that given the limited benefit, those suffering from missing periods should NOT be prescribed birth control as it provides a false sense of security about the state of one’s bones, and may discourage from attempting to recover normal cycles through eating, exercise, and stress changes.
Were you ever prescribed birth control pills to “protect your bones”?
Gersten J, et al. Impact of Extended 30 mcg EE With Continuous Low-Dose EE and Cyclic 20 mcg EE Oral Contraception on Adolescent Bone Density: A Randomized Trial. J Pediatr Adolesc Gynecol. 2016 Jun 7. pii: S1083-3188(16)30058-4. doi: 10.1016/j.jpag.2016.05.012
Biason TP, et al. Low-dose combined oral contraceptive use is associated with lower bone mineral content variation in adolescents over a 1-year period. BMC Endocr Disord. 2015 Apr 3;15:15. doi: 10.1186/s12902-015-0012-7.
Nieves JW, et al. Eating disorders, menstrual dysfunction, weight change and DMPA use predict bone density change in college-aged women. Bone. 2016 Mar;84:113-9. doi: 10.1016/j.bone.2015.12.054. Epub 2015 Dec 30.
Bergstrom I, et al. Women with anorexia nervosa should not be treated with estrogen or birth control pills in a bone-sparing effect. Acta Obstet Gynecol Scand. 2013 Aug;92(8):877-80. doi: 10.1111/aogs.12178. Epub 2013 Jun 15.
Lebow J, and Sim L. The influence of estrogen therapies on bone mineral density in premenopausal women with anorexia nervosa and amenorrhea. Vitam Horm. 2013;92:243-57. doi: 10.1016/B978-0-12-410473-0.00009-X.