Does the O-pill (oral contraceptive pill) cause loss of bone density?

From the Guidelines

Oral contraceptive pills (OCPs) generally do not cause significant bone density loss in most women, and the estrogen in combined hormonal contraceptives may actually help maintain bone mineral density in adult women. According to the most recent and highest quality study available, 1, there is no significant evidence to suggest that OCPs cause loss of bone density. In fact, the study suggests that transdermal oestradiol therapy, which is similar to the estrogen found in combined hormonal contraceptives, can help maintain bone homeostasis in women with functional hypothalamic amenorrhoea.

Some key points to consider:

• Combined oral contraceptives may inhibit IGF-1 production, which can decrease osteoblastic activity, but this effect is not significant enough to cause significant bone density loss in most women.
• Progestin-only contraceptives, such as depot medroxyprogesterone acetate (DMPA or Depo-Provera) injections, have been associated with temporary decreases in bone mineral density, but this effect is generally reversible after discontinuation.
• Women with risk factors for osteoporosis, such as family history, smoking, low body weight, or certain medications, should discuss their concerns with their healthcare provider when choosing a contraceptive method.
• Maintaining adequate calcium intake (1000-1200mg daily), vitamin D (600-800 IU daily), regular weight-bearing exercise, and avoiding smoking are important general measures for bone health regardless of contraceptive choice.

Overall, the available evidence suggests that OCPs are not a significant risk factor for bone density loss in most women, and that other factors such as nutrition, exercise, and overall health are more important for maintaining bone health.

From the Research

O-Pill OTC Contraceptive and Bone Density

• The relationship between O-pill (oral contraceptive pill) use and bone density is complex, with varying effects depending on factors such as age, duration of use, and estrogen dose 2, 3, 4.
• A study published in 2010 found that prolonged use of low-dose oral contraceptives (<30 mcg ethinyl estradiol) may adversely impact bone density in young adult women, particularly in those using them for more than 12 months 2.
• Another study from 2001 suggested that low-dose oral contraceptives may impede the formation of peak bone mass in very young women (less than 20 years old) by reducing bone metabolism, but emphasized the need for more reliable studies to confirm this finding 3.
• In contrast, a 2004 study found that oral contraceptives can have a positive effect on bone mineral density, particularly in women with hypothalamic amenorrhea or estrogen deficiency, by providing a replacement therapy with continuous exposure to exogenous estrogens 4.
• However, a prospective study published in 1993 found that oral contraceptive pill use was associated with a higher risk of fractures in women, although this finding was not significant for forearm fractures specifically 5.
• A review of 13 studies on low-dose oral contraceptives and bone mineral density found that most studies showed a positive effect of OC use on BMD, with no studies showing a decrease in BMD with OC use, providing fair evidence to support the position that OC use has a favorable effect on BMD 6.