By Stuart Shalit, DO, OB/GYN—Virtua Obstetrics & Gynecology 

If you want to prevent pregnancy, a long-acting reversible contraceptive (LARC) is a safe and effective birth control option. But, the number one question women ask their ob/gyns remains—will it make me gain weight? 

Here are the facts so you can decide if a LARC is right for you. 

What are LARCs?

A LARC is a birth control option that can prevent pregnancy for several months or years, depending on the type you choose. In addition, LARCs are reversible. This means they can be removed or stopped if or when you’re ready for pregnancy.  

There are three types: 

• The intrauterine device (IUD), a small T-shaped device that’s inserted into your uterus (Mirena, Liletta, Paragard and others)
• The implant, a small plastic rod placed under the skin in your arm (Nexplanon)
• The injection, or shot (Depo-Provera)

These forms of birth control are administered right in your doctor’s office—no surgery involved. They’re hardly noticeable, don’t interfere with your ability to have sex, and rarely have side effects.

Do LARCs cause weight gain?

Many women believe that birth control will make them gain weight. Contraceptives that contain hormones, including LARCs, do have the potential to cause slight, short-term weight gain. 

In most cases, weight gain related to the use of LARCs is limited to 3-5 pounds and is caused by temporary bloating and water retention similar to what you might experience during your period. It’s also dependent on the hormone levels already in your body, as well as how your body reacts to the hormones in your LARC. Weight also is influenced by lifestyle factors and other physical changes. 

There’s evidence that suggests that the birth control injection is more likely to cause weight gain, which is due to the higher dose of hormones given at one time. The copper IUD doesn’t contain hormones and, therefore, doesn’t cause weight gain. 

If you use a LARC and gain some weight that persists for more than a few months, it’s probably not related to your birth control. Pay attention to your diet and activity level and make adjustments to see if that helps you shed unwanted pounds. If you can’t budge the weight, talk to your doctor. He or she may want to check for other conditions that could cause weight gain, including thyroid problems or polycystic ovary syndrome (PCOS). 

How effective are LARCs at preventing pregnancy?

Unlike other birth control methods such as the pill, ring or patch, LARCs aren’t affected by patient compliance and are more than 99 percent effective at preventing pregnancy. 

LARCs include the copper or progestin IUDs, the injection and the implant, which are all methods of contraception that women can use for an extended length of time. Unlike the pill, which a woman must remember to take at the same time every day, the IUD and implant are inserted once and are highly effective for 3, 5, or up to 10 years without any daily effort. The injection takes a little more effort as it must be administered every 3 months. However, all forms are more error-proof, more effective, and often better tolerated than the hormonal birth control pill. 

LARCs also have a lower failure rate than female sterilization (having your “tubes tied”). That’s because the effectiveness of a sterilization procedure depends on the way the surgery is performed and how your body heals afterward.

 Although LARCs are highly effective at preventing pregnancy, it’s important to remember that they don’t protect against sexually transmitted infections (STIs). 

How do LARCs prevent pregnancy?

All LARCs work differently to prevent pregnancy.

Mirena, Liletta, Kyleena and Skyla—are IUDs that contain a hormone called progestin that makes them very effective at preventing pregnancy. In addition, they can make your period lighter, or in some cases, stop it completely. IUDs that use progestin last for 3-5 years. 

Paragard is another IUD, but it’s made of copper and hormone-free. It interferes with sperm movement, egg fertilization and embryo implantation. It can be used for up to 10 years. 

Nexplanon, the birth control implant, is placed under the skin in your arm and uses a form of progesterone to prevent pregnancy. It can make your period lighter and lasts for up to 3 years. 

Depo-Provera contains a hormone similar to progesterone that’s injected in your arm or buttocks. You need to visit your doctor’s office every 3 months for an injection. 

Are LARCs right for me?

LARCs can be a good choice if you have no short-term plans to become pregnant, or if you’re looking for a birth control option that doesn’t require you to do anything else to prevent pregnancy. Talk to your doctor to find one that’s a good fit for your lifestyle. 

To schedule an appointment with a Virtua OB/GYN, call 1-888-847-8823.