Bone Density Effects in IUD Users
IUD users do not experience clinically significant bone density effects, with the exception of DMPA injection users who have documented bone loss that is not seen with IUDs.
Key Distinction: IUDs vs. DMPA
The critical point is distinguishing between intrauterine devices and depot medroxyprogesterone acetate (DMPA) injections, as these are fundamentally different contraceptive methods:
- DMPA injections carry a black box warning for decreased bone density, which normalizes after cessation of use 1
- IUDs (both copper and levonorgestrel) are NOT associated with clinically significant bone loss 1
Evidence for Levonorgestrel IUDs
The levonorgestrel-releasing IUD is associated with minimal to no bone loss 1. This is a key clinical distinction from DMPA:
- Data on bone mineral density effects of the contraceptive implant are scant, but given higher estradiol levels in implant users compared to DMPA users, the implant is presumed to have less effect on BMD 1
- Research comparing levonorgestrel IUD users to copper IUD users found no significant differences in bone mineral density 2
Evidence for Copper IUDs
Copper IUDs are hormone-free and have no effect on bone density 1:
- Women with any bone health concerns can use copper IUDs without restriction (U.S. MEC Category 1) 1
- Multiple studies comparing copper IUD users to other contraceptive users found no adverse bone density effects 3, 4, 5
Research Data on Actual Percentages
While guidelines clearly state IUDs do not cause bone loss, research studies provide comparative data:
- In one study, 2.4% of copper IUD users had osteoporosis compared to 29.8% of DMPA users, demonstrating the stark difference between these methods 3
- Studies of postmenopausal women who used copper IUDs until menopause showed no significant BMD differences compared to baseline expectations 4
- Long-term copper IUD users (mean 14.7 years) showed normal bone density measurements 5
Clinical Bottom Line
No percentage of IUD users experience bone density effects attributable to the IUD itself. The confusion likely stems from conflating DMPA (an injectable progestin with documented bone effects) with IUDs (intrauterine devices without such effects) 1.