Episode 246: Do GLP-1 Medications Affect Your Bones?

[00:00:00] Welcome back to the Back on Track: Achieving Healthy Weight Loss, where I help you get on track and stay on track with your weight loss journey. I'm your host, Dr. Alicia Shelly. So let's get started.

[00:00:28] Welcome back to the Back on Track Achieving Healthy Weight Loss podcast. I'm your host, Dr. Alicia Shelly. Now, I recently had a patient that asked me a great question in clinic. She said, Dr. Shelly, I've heard that GLP-1 medications can cause muscle loss. Does that mean they can hurt my bones too?

[00:00:50] I was like, that's an excellent question! Because we talk a lot about weight loss, we talk about blood sugar, we talk about side effects like nausea, vomiting, constipation, but we do not spend enough time talking about bone health. So today, I'm going to answer all of that question. I'm going to share with you what we know, what we don't know, what we need more studies looking at, because it's an excellent question.

[00:01:19] I have seen so many individuals, especially as they age, fall and break a hip and break a spine, and then it just really reduces their mobility, and it puts them at risk for even dying within a year's time. So it is so important that we do our best to protect the bones that we have. So, to answer the question, do GLP-1 medications affect your bones? The short answer is, probably not directly.

[00:01:49] But, there are some important things you need to know if you're taking one of these medications. So let's dive in. Now, when I say GLP-1 medications, I'm including drugs like Wegovy, Ozempic, Zepbound, Manjaro, Wegovy pill, Fundeo, all the things. The category is getting larger and larger and larger.

[00:02:10] And these medications, how they work, they help people with losing weight, they help with reducing hunger, also helping them feel full sooner. Also, it's slowing down digestion in the stomach. So, therefore, food leaves the stomach slower. And, therefore, sometimes you may have some malabsorption where you're not getting enough protein that the body needs or enough vitamins that the body needs.

[00:02:35] And for some people, when it comes to these GLP-1 medications, they are life-changing. I forgot to mention, they also can reduce blood pressure. They can reduce blood sugar. They've been shown to lower your risk of dying from heart attacks or stroke or cardiovascular disease. Also, they've been shown to reduce fatty liver disease, especially if you have scarring or fibrosis. And then, also, they've been shown to reduce your sleep apnea.

[00:03:02] So, these groups of medication, and then also diabetes as well, these groups of medication can really help a lot. However, and when patients start to lose weight, they improve their blood sugar, they lower their blood pressure, sleep better, and often feel more energetic. But whenever somebody loses a certain amount of weight, we also need to think about what's happening to their muscles and bones.

[00:03:28] The good news is that studies so far have not shown that GLP-1 medications directly damage bones. Researchers have looked at thousands of patients taking these medications. Most studies have found that people taking the GLP-1 medications don't have a higher risk of fractures compared with people not taking them.

[00:03:48] In one 2025 review study article by Zhang et al., it actually found that GLP-1s reduced fracture risks. However, there's also another population-based cohort study of looking at older adults, individuals greater than the age of 65, and shown that they was associated with 11% increased fracture risks.

[00:04:12] But more studies need to be done to look at the older adult population to see what is their risk. Is it the medication or is it because they are older that put them at risk as well? When we look at the overall research that has been done, medication itself does not appear to be weakening the bones. However, more studies need to be done so that we can really get a clear understanding in all populations. So from the younger population to the older population, what are your risks?

[00:04:42] But, you know, the story doesn't just stop at GLP-1s and bone health. You know, we really need to talk a little bit more in depth because the concern is not the medication. It's actually weight loss. So let me explain. Our bones are living tissue. They are constantly rebuilding themselves. Bones become stronger when they are challenged. When you're working out, when you're climbing the stairs, they actually build up muscle, which challenges the bones.

[00:05:09] Many patients I've recommended physical therapy for and they may be hesitant. They're like, oh, I don't want to go to physical therapy. But when they finally go and start to incorporate these exercises, they find that they're stronger. They may not need that cane as much. They may be able to move better because of strengthening the muscles as well as strengthening those bones.

[00:05:33] And so activities like walking, climbing stairs, lifting weights help keep your bones healthy. So when you have a patient who loses a lot of weight, whether it's 25 pounds, 30 pounds, 50, 100 pounds, it is so helpful on the knees. In fact, I remember one doctor telling me that when you lose 10 pounds, it's like losing 40 pounds of pressure on your joints and especially on your knees.

[00:05:59] And that can lead to less knee pain because you're not necessarily having them bone on bone. But also it can reduce some of the signals that help the bones stay strong. And this is not unique to GLP-1 medications. Do we just see this in weight loss in general? And this is where things get really important, especially when we talk about muscle loss. When people start to lose weight, they usually lose both fat and lean tissue. And lean tissue meaning muscles, certain organs as well.

[00:06:29] So lean tissue includes muscle. In one of the Sermon-1-Dextus study, our sub-study, terzepatide, which is another scientific name for zepbound or manjaro, had a 21.3% weight loss. And out of that 21.3% weight loss, 75% of that weight loss was fat mass, 25% was lean mass or muscle.

[00:06:53] In the step one body composition analysis with semaglutide or WGOV or WGOV-PIL or ozempic, participants had major reduction in fat mass and some reduction in lean mass. While the overall body composition improved. Although when we looked at the difference between fat mass and lean mass, 45% of the weight loss came from lean mass. So a little bit higher than the Sermon-1-Dextus study.

[00:07:21] But the good news is that most of the weight loss on GLP-1 medications comes from fat and not necessarily muscle. However, you can have some muscle loss as well. And the reason why this matters is because muscles and bones work together. Strong muscles help to strengthen bones. Strong muscles also helps improve balance and reduce loss, which is why we send everybody to physical therapy because we want to improve your balance.

[00:07:49] If muscle loss becomes significant, it may increase the risk of falls and fractures later in life. And that's why preserving muscle is one of the most important, important, important goals during weight loss. I tell my patients all the time, we just don't want smaller bodies. We want stronger bodies. And I preach, you need to be doing strength training as well as cardio in your daily walk.

[00:08:16] And it definitely makes me very discouraged when you have somebody who is like not doing it. And you're like, man, you're going to regret this decision later. So who should be paying more extra attention when it comes to their bones? So there are some people who are already at higher risk for having weak bones. This includes women after menopause because your body starts to reduce how much vitamin D and calcium is in the bloodstream.

[00:08:44] Also, adults over the age of 65 need to pay attention. People who have a family history or a personal history of osteoporosis or osteopenia. A person who's had a fracture in the past. That puts you at even more risk for weak bones. Also, if you had bariatric surgery because you have more malabsorption that can lead to weak bones. And people who take steroids for a long period of times, that can actually eat up the bones as well.

[00:09:11] If you have a low vitamin D level, it can put you at extra risk. As well as if you're not eating enough calcium, you can be at extra risk. And if you fall into one of these groups, it's worth having a conversation with your healthcare provider about your bone health and what you should be doing at this time. So I have about five tips for you on how you can protect your bones while taking a GOP-1. Tip number one, eat enough protein. I cannot stress this enough.

[00:09:41] Eat enough protein. Protein is essential for maintaining muscle. Many patients on GOP-1 medications eat much less than they had before. They're not able to finish their plate. So a lot of times that protein is just sitting there. And it's okay if you can't finish your plate. But we want to make sure that at least what you do finish is the protein first. So make sure to eat that protein first.

[00:10:06] And then it's important to not only focus on lean meats, fish, eggs, Greek yogurt, cottage cheese, beans, tofu. All areas that have higher protein for your body. And if you're vegetarian, no problem. You have beans. You have tofu. You have other things you can do to kind of incorporate. You'd be more healthy but making sure you're eating more of the protein. For many of my patients, I usually recommend around them eating about 80 to 100 grams of protein per day. Although individual needs may vary.

[00:10:35] If you are not exercising right now, then 1.2 grams of protein per how many kilograms you weigh is a good start. If you are very active in the gym, then you need to go higher. 1.5 grams of protein per how many kilograms that you weigh. Which will help you to kind of know what to shoot for. All right. Tip number two. Strength training. If all you're doing is walking right now, that's a great start.

[00:11:03] But it is important that you add resistance training to your routine. Now, you don't have to become a bodybuilder. You don't need to look like The Rock or Arnold Schwarzenegger. You sometimes can just start at simple activities such as resistance bands, dumbbells, whip machines, bodyweight exercises to help streep in and tone. I love Pilates. I love yoga. It's a great way how to strength train, but it's a little bit lower impact.

[00:11:31] Because remember, muscles help protect bones. All right. Tip number three. Get enough calcium. I can't stress it enough. Get enough calcium. Calcium is a building block for your bone health. Great sources of calcium include milk, yogurt, cheese, fortified plant milks, leafy green vegetables. There are many places where you can get your calcium.

[00:11:56] And if you're not getting enough calcium through food, talk to your health care provider about whether a supplement will make sense to you. Also, it's important to not forget about that vitamin D because vitamin D helps your body to absorb calcium better. So it's important to make sure that your levels are in a great range or at least over greater than 30. Many adults who have low vitamin D and they don't know it because they may not be going out in the sun. You need the sun in order to activate vitamin D in the body.

[00:12:26] So you need at least 10 minutes of sun and not saying you could put on sunscreen, but make sure you're getting out into the open and getting that sun. Also, your health care provider can check your vitamin D with a simple blood test. Now, how much should you be taking of calcium and vitamin D? The Bone Health and Osteoporosis Foundation recommends calcium first from food, supplementing only when needed.

[00:12:51] So the recommended 1,000 milligrams per day for women ages 50 and younger and men ages 670 and younger should be 1,000 milligrams daily and 1,200 milligrams daily for women 51 and older and men 71 and older. They also recommend vitamin D between that doses of 40 to 800 under the age of 50 and an 800 to 1,000 over the age of 50.

[00:13:17] Now, my last tip for you today is ask your provider about a bone density test because some patients may benefit from a bone density scan and to see where they are. So if they do have some osteopenia, which is a low bone mass, they can work on it so that they won't have osteoporosis. This testing is called the DEXA scan. Now, this is especially important if you are over the age of 65, have gone through menopause, had previous fractures, have osteoporosis risk fractures.

[00:13:46] The DEXA can help scan and identify your bone loss very, very early. So when patients ask me if a GOP-1 medication hurts their bones, here is what I tell them. Number one, the medication itself does not appear to weaken bones. But whenever we lose weight, we need to protect our bones to protect our muscles by eating enough protein, staying active and doing strength training. And that's really the key message. The goal isn't just to lose weight.

[00:14:15] The goal is to have healthy weight loss so that we're stronger, we can do the things we want to do and not feel weaker and unwell because we lost weight. We want to lose weight while keeping as much muscle and bone strength as possible. So GLP-1s have helped millions and millions of people improve their health. The current evidence suggests that these medications do not directly increase fracture risk or significantly weaken bones. But weight loss changes the body.

[00:14:45] And that's why it's important to think about the whole picture. Eating enough protein, strength training regularly, getting enough calcium and vitamin D. Make sure you talk to your healthcare provider if you have concerns about osteoporosis or your bone health. Because success isn't just about the number on the scale. It's about staying strong, being healthy and active for years to come. Thank you so much for your time.

[00:15:11] Thank you for listening to another episode of the Back on Track Achieving Healthy Weight Loss podcast. Until next time, stay strong, stay committed and stay consistent. And remember, we are stronger together.