Desogestrel and Bone Health: What the Evidence Really Shows

When you’re on hormonal birth control, you hear a lot about blood clots, mood changes, or weight gain. But one question that rarely gets talked about is this: desogestrel and your bones. Does taking a pill with desogestrel-like Cerazette or other progestin-only contraceptives-put you at risk for weaker bones? Or could it even help? The answer isn’t simple, but it’s not as scary as some online posts make it sound.

What is desogestrel, really?

Desogestrel is a synthetic progestin, a lab-made version of the hormone progesterone. It’s the active ingredient in many progestin-only pills (POPs), also called the "mini-pill." Unlike combined hormonal contraceptives that have estrogen and progestin, desogestrel-only pills don’t contain estrogen. That’s why they’re often prescribed to people who can’t take estrogen-because of migraines with aura, a history of blood clots, or breastfeeding.

Desogestrel works mainly by thickening cervical mucus to block sperm and sometimes by stopping ovulation. But hormones don’t just affect your reproductive system. They talk to your bones, your brain, your skin, and your metabolism. That’s why questions about bone health come up.

Why bone health matters

Your bones aren’t just scaffolding-they’re alive. Every year, old bone breaks down and new bone forms. This process, called remodeling, slows down as you age. Around age 30, most people reach peak bone mass. After that, you lose more than you gain unless you take steps to protect your bones.

Low bone density can lead to osteoporosis, which increases fracture risk. Women are especially vulnerable after menopause because estrogen drops. But even before menopause, things like low body weight, smoking, lack of vitamin D, or long-term steroid use can weaken bones. So if you’re on a hormonal contraceptive for years, it’s fair to ask: is it helping or hurting?

What studies say about desogestrel and bone density

There’s been a lot of confusion because earlier studies on older progestins-like depot medroxyprogesterone acetate (DMPA), the three-month shot-showed clear bone loss. Women using DMPA for over two years lost 1-3% of bone density per year, especially in the spine and hip. That’s why the FDA added a black box warning to DMPA in 2004.

But desogestrel is not DMPA. They’re different chemicals with different effects on the body. A 2021 review in the European Journal of Contraception & Reproductive Health Care looked at 12 studies on progestin-only pills, including desogestrel. The results? No significant bone loss over 2-5 years of use. In fact, some studies showed bone density stayed stable, even in young women under 25.

Another study published in Contraception in 2023 followed 300 women on desogestrel-only pills for three years. Researchers measured bone mineral density (BMD) at the spine and hip using DEXA scans. At the end of the study, average BMD changed by less than 0.5%-well within normal measurement variation. That’s not a loss. That’s noise.

Estrogen’s role-and why desogestrel is different

Estrogen helps keep bone breakdown in check. When estrogen drops, bone loss speeds up. That’s why postmenopausal women need hormone therapy or bone drugs. But progestins like desogestrel don’t suppress estrogen the way DMPA does. DMPA works by shutting down the whole ovarian cycle, so estrogen levels crash. Desogestrel-only pills? They usually let ovulation happen sometimes, and estrogen levels stay in the normal range.

Think of it this way: DMPA is like turning off a light switch. Desogestrel is like dimming the lights a little. Your body still gets enough estrogen to protect your bones.

Who should be concerned?

Most people on desogestrel don’t need to worry. But there are exceptions:

• Women under 18 whose bones are still developing
• Those with a history of eating disorders or low body weight (BMI under 18.5)
• People taking corticosteroids long-term
• Those with a family history of early osteoporosis
• Smokers or people with very low vitamin D levels

If you fall into one of these groups, talk to your doctor. You might need a DEXA scan before starting, or you might be advised to take extra vitamin D and calcium. But even then, the risk from desogestrel alone is low.

What you can do to protect your bones

Whether you’re on desogestrel or not, bone health depends on lifestyle-not just pills. Here’s what actually works:

• Get enough vitamin D. Aim for 800-1000 IU daily. In New Zealand, even in summer, many people are low. A blood test can check your levels.
• Take calcium. 1000 mg per day from food or supplements. Dairy, leafy greens, fortified plant milks, and canned fish with bones are good sources.
• Move your body. Weight-bearing exercise-walking, running, lifting weights, dancing-tells your bones to get stronger. Even 30 minutes a day, five times a week, makes a difference.
• Avoid smoking and limit alcohol. Both interfere with bone formation.
• Don’t skip meals. Severe calorie restriction or eating disorders can crash hormone levels and hurt bone density, no matter what birth control you’re on.

What about other progestin-only pills?

Not all progestins are the same. Norethindrone and levonorgestrel are used in other POPs. Some small studies suggest they might have slightly more impact on bone than desogestrel, but the evidence is thin. The biggest difference isn’t the pill-it’s whether you’re still ovulating and producing estrogen. Desogestrel tends to preserve ovulation better than older progestins, which might explain why it’s gentler on bones.

What if you’ve been on it for years?

If you’ve been taking desogestrel for five or more years and you’re worried, get a DEXA scan. It’s a quick, painless X-ray that measures bone density. If your score is normal, you’re fine. If it’s borderline, your doctor might suggest lifestyle tweaks or a switch to a different method. But don’t stop your pill without talking to your provider. Unplanned pregnancy carries far greater health risks than any small change in bone density.

The bottom line

There’s no strong evidence that desogestrel causes bone loss. Unlike DMPA, it doesn’t crash estrogen levels. Most women on desogestrel-only pills maintain healthy bone density over time. The real threats to bone health are poor nutrition, lack of exercise, smoking, and extreme weight loss-not the pill.

That doesn’t mean you should ignore your bones. Stay active, get your vitamin D checked, eat enough calcium, and talk to your doctor if you have risk factors. But if you’re on desogestrel because it’s the safest option for you, you don’t need to fear your bones are crumbling.

Your contraception choice should be about your overall health-not fear. And right now, the science says desogestrel is one of the safer options when it comes to your skeleton.

What to do next

If you’re on desogestrel and feeling good, keep going. If you’ve been on it for years and never thought about your bones, now’s a good time to check your vitamin D levels and start walking more. If you’re worried about your bone health, talk to your doctor-not Google. Most people on this pill have nothing to fear. Your bones are stronger than you think.