Unintentional weight gain likely has more to do with the natural aging process and your overall lifestyle than your choice of birth control.

An IUD is one form of contraceptive used by people who menstruate. It’s a small device that your doctor inserts into your uterus. It’s one of the most effective methods of reversible birth control.

Two forms of IUDs are available:

Copper IUDs

The copper IUD (ParaGard) is a plastic, T-shaped device with copper wire wrapped around it. It creates an inflammatory reaction in your uterus, which is toxic to sperm. This helps prevent pregnancy. The device lasts up to 10 years before you need to replace it.

The copper IUD may cause side effects, such as:

  • anemia
  • backaches
  • cramping
  • vaginitis
  • painful sex
  • bleeding between periods
  • heavy bleeding during periods
  • severe menstrual pains
  • vaginal discharge

Weight gain isn’t a listed side effect of the copper IUD.

Hormonal IUDs

Hormonal IUDs such as Mirena and Skyla are plastic T-shaped devices that release the hormone progestin into your uterus.

This thickens your cervical mucus to prevent sperm from reaching and fertilizing your eggs. The hormone also thins your uterine lining and helps prevent your eggs from being released.

The Skyla IUD lasts up to 3 years before you need to replace it, and the Mirena IUD can last for up to 5 years before it needs to be replaced.

Hormonal IUDs may cause side effects, such as changes in your menstrual bleeding and missed periods. Other side effects include:

Hormonal IUDs also list weight gain as a possible side effect.

One 2020 study compared weight gain with the hormonal IUD, the copper IUD, and the birth control implant among a large group of racially diverse women. The hormonal IUD showed that hormonal IUD users gained about 0.72 kg (about 1.59 lbs) on average after 12 months.

This suggests that hormonal IUDs could contribute to low levels of weight gain. It should be noted that weight gain can have many causes and that more research needs to be done.

If you choose to use an IUD, your doctor will have to insert it. Contact your doctor immediately if you experience any side effects after the IUD is inserted.

IUDs don’t prevent the spread of sexually transmitted infections (STIs). You should use other barrier methods, such as condoms, to protect yourself and your partner from STIs.

It’s commonly assumed that using certain contraception methods leads to weight gain. However, studies indicate that most people tend to gain weight during their reproductive years, regardless of their chosen birth control methods.

The National Collaborating Centre for Women’s and Children’s Health reviewed several studies on weight gain and copper IUDs. It found no evidence that IUD use affects weight.

According to the National Center for Biotechnology Information, hormonal forms of birth control probably won’t cause you to gain a lot of weight either.

If you think you’ve gained weight because of your hormonal contraceptive, talk to your doctor. There are many forms of contraceptives available.

Managing a healthy weight for you is a lifelong endeavor. More than 66 percent of women in the United States have overweight or obesity, reports the U.S. Department of Health and Human Services (HHS).

Doing what you can to maintain a healthy-for-you weight and avoid significant weight gain or loss is important to your overall health.

If you’d like to lose weight, avoid eating more calories than you burn each day. Follow these tips to have a balanced and nutrient-dense diet:

  • Eat a variety of fruits, vegetables, whole grains, low-fat dairy products, and lean sources of protein.
  • Avoid high-fat meats, fried foods, and sweets.
  • Drink plenty of water, and reduce consumption of high-calorie beverages such as soda.

You should avoid fad and elimination diets that deprive you of vitamins, minerals, and other nutrients you need.

To achieve and maintain a healthy weight, you also need to get regular physical exercise. For optimum health, your weekly exercise routine should include:

You should spend at least 150 minutes on moderate-intensity aerobic activities every week, according to the Centers for Disease Control and Prevention.

Making healthy food choices and engaging in regular physical activity can help you maintain a healthy weight.

Finding the right birth control method for you and managing your weight are important factors in staying healthy.

Talk to your doctor if you have concerns about your IUD or your weight. If you exercise and eat a well-balanced diet, but you still notice a significant fluctuation in your weight, there may be a medical reason for it.

Your doctor can help you find the best IUD based on your lifestyle, health, and reproductive plans.