Fact-Checked by: 
It is hard to keep track of the different types of intrauterine birth control devices (IUD) and their potential side effects when choosing one that is best for you. It is important to consider how the additional hormones may affect your body. IUD side effects, IUD risks, and IUD complications can be confusing. Some of the most common questions are whether or not these devices are effective and whether they can cause weight gain.
Copper and hormonal IUD birth control options are safe and effective birth control options (Hu, 2018), however, they may not be the best birth control option for everyone. Hormonal and copper IUDs have very different side effects. Two types of hormonal IUDs are etonogestrel (ENG) and levonorgestrel (LNG) releasing contraceptive implants. LNG hormonal IUD side effects include infrequent or absent periods. Other side effects of IUDs that use hormones include acne, increased weight, and breast pain (Chi, 1991).
Copper IUDs work because the copper coil on the device prevents pregnancy by destroying sperm. This type of birth control is less likely to change hormone levels in the body compared to ENG and LNG releasing implants. Therefore, they are less likely to cause hormone-associated symptoms such as acne and bleeding irregularities when compared to hormonal IUDs (Bahamondes, 2015). However, copper IUD side effects include bleeding or IUD pain in the pelvis (Chi, 1991).
Several research studies suggest that pill and patch forms of birth control may be less effective in teens that are overweight (Kaneshiro, 2011). This has not been found in IUD users.
In a randomized clinical study, women using copper IUDs did not have as much weight gain as women using hormonal implants containing ENG or LNG (Bahamondes, 2018). While copper IUD users gained less than 2.5 pounds on average after three years of using the product, hormonal implant users gained over 6.5 pounds on average.
These results were even more convincing in women weighing over 110 pounds before beginning the birth control regimen. Increased weight gain in this group was around 1.7 pounds more per year. These findings were statistically significant. This means that the increased weight gain can be linked to using a hormonal implant rather than copper IUD weight gain (Bahamondes, 2018).
Race may also be a predictor of weight gain while using hormone-based IUDs. One study found that black women had significantly more weight gain after beginning a long-term contraceptive when compared to women of other races (Vickery, 2013).
Hormonal and copper IUD use is also associated with changes to body composition. Women using copper IUDs on average had a 1.3% reduction in fat mass and a 1.0% gain of lean mass (Dal’Ava, 2012). Conversely, LNG IUD users had a 2.5% gain of fat mass and a 1.4% loss of lean mass. However, the results from this study were extremely variable. This means that these differences were not statistically significant (Dal’Ava, 2012). But these trends are noteworthy because they describe changes to body composition other than simple weight gain.
Ultimately, weight gain is a common side effect of hormone-based birth control options. This remains true with hormone-based IUDs. Weight gain is less common in copper IUD users as this is a non-hormonal birth control option (Batisa, 2016).
IUDs are reversible and relatively safe for all ages of women and adolescents (Jatlaoui, 2017). While both hormonal and copper IUDs provide effective birth control, less than 60% of LNG IUD users continue using the product after two years while more than 67% of copper IUD users continue with the devices after two years (Sivin, 1987). This difference was attributed to complications of IUD use including reduced menstruation in women using LNG IUDs.
Women that experience significant weight gain after starting a new birth control method should talk to their doctor as this may be a sign of continual weight gain in the future (Steenland, 2013).
Frequently Asked Questions
What are the different types of IUDs?
There are two main categories of IUDs. The first type uses a slow release of hormones while the second uses a copper coil to repel sperm from fertilizing an egg.
Do copper IUDs cause weight gain?
No! Copper IUDs are not linked to increased weight gain. In fact, one study found that women using copper IUDs had a slightly reduced fat mass percentage.
Do hormonal IUDs cause weight gain?
Yes! All hormonal forms of birth control have a potential side effect of weight gain. This side effect may be more likely to occur in black women than women of other races.
References
Bahamondes L, Brache V, Meirik O, Ali M, Habib N, Landoulsi S; WHO Study Group on Contraceptive Implants for Women. A 3-year multicentre randomized controlled trial of etonogestrel- and levonorgestrel-releasing contraceptive implants, with non-randomized matched copper-intrauterine device controls. Hum Reprod. 2015 Nov;30(11):2527-38. doi: 10.1093/humrep/dev221. Epub 2015 Sep 25. PMID: 26409014.
Bahamondes L, Brache V, Ali M, Habib N; WHO study group on contraceptive implants for women. A multicenter randomized clinical trial of etonogestrel and levonorgestrel contraceptive implants with nonrandomized copper intrauterine device controls: effect on weight variations up to 3 years after placement. Contraception. 2018 Sep;98(3):181-187. doi: 10.1016/j.contraception.2018.05.009. Epub 2018 May 16. PMID: 29777663.
Batista GA, Souza AL, Marin DM, Sider M, Melhado VC, Fernandes AM, Alegre SM. Body composition, resting energy expenditure and inflammatory markers: impact in users of depot medroxyprogesterone acetate after 12 months follow-up. Arch Endocrinol Metab. 2017 Jan-Feb;61(1):70-75. doi: 10.1590/2359-3997000000202. Epub 2016 Sep 5. PMID: 27598979.
Chi IC. An evaluation of the levonorgestrel-releasing IUD: its advantages and disadvantages when compared to the copper-releasing IUDs. Contraception. 1991 Dec;44(6):573-88. doi: 10.1016/0010-7824(91)90078-t. PMID: 1773615.
Dal’Ava N, Bahamondes L, Bahamondes MV, de Oliveira Santos A, Monteiro I. Body weight and composition in users of levonorgestrel-releasing intrauterine system. Contraception. 2012 Oct;86(4):350-3. doi: 10.1016/j.contraception.2012.01.017. Epub 2012 Mar 23. PMID: 22445431.
Hu LX, Hu SF, Rao M, Yang J, Lei H, Duan Z, Xia W, Zhu C. Studies of acute and subchronic systemic toxicity associated with a copper/low-density polyethylene nanocomposite intrauterine device. Int J Nanomedicine. 2018 Aug 31;13:4913-4926. doi: 10.2147/IJN.S169114. PMID: 30214197; PMCID: PMC6124463.
Jatlaoui TC, Riley HEM, Curtis KM. The safety of intrauterine devices among young women: a systematic review. Contraception. 2017 Jan;95(1):17-39. doi: 10.1016/j.contraception.2016.10.006. Epub 2016 Oct 19. PMID: 27771475; PMCID: PMC6511984.
Kaneshiro B, Edelman A. Contraceptive considerations in overweight teens. Curr Opin Obstet Gynecol. 2011 Oct;23(5):344-9. doi: 10.1097/GCO.0b013e328348ec82. PMID: 21666461.
Sivin I, Stern J, Diaz J, Diaz MM, Faundes A, el Mahgoub S, Diaz S, Pavez M, Coutinho E, Mattos CE, et al. Two years of intrauterine contraception with levonorgestrel and with copper: a randomized comparison of the TCu 380Ag and levonorgestrel 20 mcg/day devices. Contraception. 1987 Mar;35(3):245-55. doi: 10.1016/0010-7824(87)90026-6. PMID: 3111785.
Steenland MW, Zapata LB, Brahmi D, Marchbanks PA, Curtis KM. Appropriate follow up to detect potential adverse events after initiation of select contraceptive methods: a systematic review. Contraception. 2013 May;87(5):611-24. doi: 10.1016/j.contraception.2012.09.017. Epub 2012 Nov 21. PMID: 23177264.
Vickery Z, Madden T, Zhao Q, Secura GM, Allsworth JE, Peipert JF. Weight change at 12 months in users of three progestin-only contraceptive methods. Contraception. 2013 Oct;88(4):503-8. doi: 10.1016/j.contraception.2013.03.004. Epub 2013 Mar 18. PMID: 23582238; PMCID: PMC3951762.
