Levonorgestrel: What It Is, How It Works, and What You Need to Know

When you hear levonorgestrel, a synthetic progestin hormone used in birth control and emergency contraception. Also known as LNG, it’s one of the most common hormones in women’s health products. It doesn’t just prevent pregnancy—it’s designed to stop ovulation, thicken cervical mucus, and make the uterus less friendly to implantation. You’ll find it in daily pills, long-term IUDs, and morning-after pills. But it’s not the same as estrogen-based birth control. It works differently, has fewer side effects for some, and is safe even if you can’t take estrogen.

Levonorgestrel is the active ingredient in Plan B, a widely used emergency contraceptive, and also in Mirena, a hormonal IUD that lasts up to seven years. These aren’t just brand names—they’re tools that rely on the same hormone, delivered in different ways. One gives you fast, single-use protection. The other gives you steady, long-term control. Both are backed by decades of research. But not everyone reacts the same. Some get lighter periods. Others get spotting, headaches, or mood changes. It’s not a one-size-fits-all solution, and knowing how it works helps you decide if it’s right for you.

Levonorgestrel doesn’t cause abortion. It works before pregnancy begins. If you’re already pregnant, it won’t harm the embryo or end the pregnancy. That’s a common myth. It also doesn’t protect against STIs. And while it’s available over the counter in many places, that doesn’t mean it’s always the best choice. If you’re using it often as emergency contraception, it’s a sign you might need a more reliable method. There are alternatives—like ulipristal acetate or copper IUDs—that work better for some people, especially if you’re overweight or need protection beyond 72 hours.

What you’ll find in the posts below are real stories and clear comparisons. You’ll see how levonorgestrel stacks up against other hormonal options, what side effects people actually report, and how it fits into broader health decisions—like managing acne, heavy periods, or endometriosis. You’ll also find advice on when to use it, when to avoid it, and how to tell if it’s working for you. This isn’t just about taking a pill. It’s about understanding your body, knowing your options, and making choices that fit your life—not just your prescription.