Bone mineral density (BMD) is a measure of bone density, reflecting the strength of bones as represented by calcium content. Bone density is the amount of bone tissue in a certain volume of bone. BMD can be an indirect indicator of osteoporosis and fracture risk. Whereas it appears that combination birth control pills maybe associated with increased bone density among women in the later reproductive years, research on other combination hormonal methods is limited. The use of Depo Provera and Implanon may actually decrease BMD. In fact, Depo Provera contains a FDA black box warning that Depo Provera use may lead to significant bone mineral density loss.
Hormonal contraception (like the Pill) tends to be a very popular contraceptive choice for many women, yet women may be using this type of birth control and not even be aware of its noncontraceptive benefits. Some hormonal contraceptives have shown some ability to increase bone mineral density (BMD). Please keep in mind that women may react differently to certain contraceptive methods, so this information is intended to be a general overview. Also, it is important to point out that the chief reason to use hormonal birth control is for contraception (to prevent an unintended pregnancy) -- possible noncontraceptive benefits of birth control should be considered when determining which hormonal method to use.
The following is a list of various prescription birth control methods that have been shown to have beneficial effects on bone mineral density:
The Pill: oral contraceptives have been reported to have positive effects on BMD. This may be due to estrogen being a powerful inhibitor of bone resorption. Combination birth control pill use is associated with increased bone density among women in the later reproductive years. Longer durations of use (greater than 10 years) is associated with greater increases in BMD. It has also been suggested that using combined OCs at times of estrogen deficiency may reduce subsequent fracture risk. Research, however, appears to be somewhat mixed. One systematic review examining the use of the pill and bone mineral density concluded that there was fair evidence that using combination birth control pills increased BMD. Yet other data concludes that adolescent and young adult women who use combination OCs will have lower BMD than nonusers (higher calcium intake may provide protection in this circumstance). Studies also show that combined OC use in perimenopausal and postmenopausal women led to preserved bone mass whereas non-pill users lost BMD. Most of the research on this topic does not specify the formulation (synthetic estrogen/progesin) of the combination birth control pills investigated in the study
- NuvaRing: the evidence for other combined hormonal methods is limited. One research study suggests that bone mineral density is lower among premenopausal users of the NuvaRing than in nonusers.
- Depo Provera and Implanon: several research studies have found decreased bone mineral density in users of progestin-only methods, the Depo Provera injection and Implanon implant. Additional data raise concern that Depo Provera, followed by low-dose OC pill use (20 micrograms of ethinyl estradiol), may slow bone recovery. Depo Provera contains a FDA black box warning that Depo Provera use may lead to significant bone mineral density loss. Additional data raise concern that Depo Provera use, followed by low-dose pill use (20 micrograms of ethinyl estradiol), may slow bone recovery. Depo Provera contains a black box warning that says, "Use of Depo-subQ Provera 104 or Depo Provera may cause you to lose calcium stored in your bones. The longer you use Depo Provera, the more calcium you are likely to lose. The calcium may not return completely once you stop using Depo Provera. Loss of calcium may cause weak bones that could increase the risk that your bones might break, especially after menopause. It is not known whether your risk of developing osteoporosis may be greater if you are a teenager when you start to use Depo Provera. You should only use Depo Provera long term (more than 2 years) if other methods of birth control are not right for you." This warning means that women who use Depo Provera may lose significant BMD. Therefore, it is important that you discuss the risks and benefits of using Depo Provera with your doctor as well as discuss your overall bone health and risk factors for osteoporosis. It is also recommended that most women use Depo Provera for no more than two years.
Bahamondes L, Monteiro-Dantas C, Espejo-Arce X, Dos Santos Fernandes AM, Lui-Filho JF, Perrotti M, et al. "A prospective study of the forearm bone density of users of etonorgestrel- and levonorgestrel-releasing contraceptive implants." Hum Reprod 2006;21:466–70. Accessed via private subscription.
Berenson AB, Rahman M, Breitkopf CR, Bi LX. "Effects of depot medroxyprogesterone acetate and 20-microgram oral contraceptives on bone mineral density." Obstet Gynecol 2008;112:788–99. Accessed via private subscription.
Cundy T, Cornish J, Roberts H, Elder H, Reid IR. "Spinal bone density in women using depot medroxyprogesterone contraception." Obstet Gynecol 1998;92:569–73. Accessed via private subscription.
Di X, Li Y, Zhang C, Jiang J, Gu S. "Effects of levonorgestrel-releasing subdermal contraceptive implants on bone density and bone metabolism." Contraception 1999; 60:161–6. Accessed via private subscription.
Gambacciani M, Ciaponi M, Cappagli B, Benussi C, Genazzani AR. "Longitudinal evaluation of perimenopausal femoral bone loss: Effects of a low-dose oral contraceptive preparation on bone mineral density and metabolism." Osteoporos Int 2000;11:544–8. Accessed via private subscription.
Garnero P, Sornay-Rendu E, Delmas PD. "Decreased bone turnover in oral contraceptive users." Bone 1995;16:499–503. Accessed via private subscription.
Kleerekoper M, Brienza RS, Schultz LR, Johnson CC. "Oral contraceptive use may protect against low bone mass." Henry Ford Hospital Osteoporosis Cooperative Research Group. Arch Intern Med 1991;151:1971–6. Accessed via private subscription.
Kuohung W, Borgatta L, Stubblefield P. "Low-dose oral contraceptives and bone mineral density: An evidence based analysis." Contraception 2000;61:77–82. Accessed via private subscription.
Lindsay R, Tohme J, Kanders B. "The effect of oral contraceptive use on vertebral bone mass in pre- and postmenopausal women." Contraception 1986;34:333–40. Accessed via private subscription.
Martins SL, Curtis KM, Glasier AF. "Combined hormonal contraception and bone health: A systematic review." Contraception 2006;73:445–69. Accessed via private subscription.
Pfizer. (2005) "Depo-SubQ Provera 104." Accessed 3/4/11. http://labeling.pfizer.com/ShowLabeling.aspx?id=549
Pfizer. (2004) "Depo Provera: Contraceptive Injection." Accessed 3/4/11. http://labeling.pfizer.com/ShowLabeling.aspx?id=522
Recker RR, Davies KM, Hinders SM, Heaney RP, Stegman MR, Kimmel DB. "Bone gain in young adult women." JAMA 1992;268:2403–8. Accessed via private subscription.