GLP1s and Iron Deficiency Anemia

You've been taking your GLP-1 medication for months, celebrating the steady weight loss and better blood sugar control, when suddenly you notice something's off. That afternoon energy crash feels heavier than usual. Climbing the stairs leaves you breathless. Your friend comments that you look a bit pale. You dismiss it as just being busy, but these small signs might be telling a bigger story about what's happening with your blood health.

Recent research suggests that GLP-1 receptor agonists—medications like Ozempic, Wegovy, and Zepbound—may increase the risk of iron deficiency anemia. With millions of Americans now using these medications, understanding this potential connection has never been more important.

Important Note: The research on GLP-1s and iron deficiency is still emerging, and we're continuing to learn about these effects. This information is meant to help you have informed conversations with your healthcare team, not to replace professional medical advice.

 

Understanding Iron Deficiency Anemia

Iron deficiency anemia occurs when your body doesn't have enough iron to produce healthy red blood cells. Without adequate iron, your body can't make enough hemoglobin—the protein that carries oxygen throughout your body. This can leave you feeling tired, weak, and short of breath.

Iron deficiency anemia is the most common type of anemia worldwide, affecting over 1.2 billion people globally. Women, vegetarians, and people with certain medical conditions are at higher risk. The condition develops gradually, often starting with depleted iron stores before progressing to full anemia.

Symptoms include fatigue, weakness, pale skin, brittle nails, unusual cravings for ice or starch, and restless leg syndrome. Because these symptoms can be subtle at first, many people don't realize they're developing iron deficiency until it significantly impacts their daily life.

 

The GLP-1 Revolution: From Diabetes to Weight Management

Why This Matters Now

The use of GLP-1 medications has exploded in recent years. What started as a diabetes treatment has become a weight management phenomenon, with prescriptions increasing by over 300% between 2021 and 2023. [5] Understanding the full health implications of these widely used medications is crucial for the millions of Americans taking them.

The Journey from 2005 to Today

GLP-1 receptor agonists aren't entirely new—the first medication in this class, Byetta, was approved for type 2 diabetes treatment in 2005. However, it wasn't until 2014 that the first GLP-1 agonist received approval for chronic weight management.

These medications work by mimicking GLP-1 (glucagon-like peptide-1), a hormone naturally released by your intestines when you eat. An "agonist" is a substance that activates specific receptors in your body—in this case, GLP-1 receptors. When activated, these receptors trigger several responses: they stimulate insulin production to help regulate blood sugar, slow gastric emptying (how quickly food leaves your stomach) and suppress appetite while promoting feelings of fullness.

This appetite suppression drives significant weight loss, but the same mechanism that reduces food intake may also contribute to nutritional challenges, including potential iron deficiency.

 

The Iron Connection: Understanding the Science

How GLP-1s May Affect Iron Levels

The relationship between GLP-1 medications and iron deficiency involves several interconnected mechanisms that researchers are still working to fully understand.

Reduced Food Intake: The appetite-suppressing effects of GLP-1s can lead to substantially reduced food intake. While this drives weight loss, it may also mean consuming fewer iron-rich foods. Some people report eating 30 to 50% less food than before starting these medications, which can significantly impact overall nutrient intake.

Gastric Emptying Changes: GLP-1 receptor agonists significantly slow gastric emptying, the process by which food moves from the stomach to the small intestine. This helps with satiety and blood sugar control. However, it can also delay and potentially reduce iron absorption and other nutrients. Iron absorption is most efficient in the duodenum (the first part of the small intestine), and delayed gastric emptying may interfere with this process.

Potential Physiological Changes: Some studies suggest that GLP-1 receptor agonists may directly influence iron metabolism, though the exact mechanisms are still being investigated.

 

Real-World Evidence

These three key studies illustrate the connection between GLP-1 medications and iron levels from different angles:

A recent study published in BMJ Open Diabetes Research and Care found that people with diabetes taking GLP-1 receptor agonists had approximately 30% lower ferritin levels compared to those taking other diabetes medications. [1] Ferritin is a key marker of iron stores in the body.

Another significant study published in JAMA Network Open compared anemia risk between patients taking GLP-1 receptor agonists and those taking SGLT-2 inhibitors (another class of diabetes medications). The research followed nearly 14,000 patients with diabetes and chronic kidney disease for a median of 2.5 years. Patients taking GLP-1 receptor agonists had a higher incidence of anemia than those taking SGLT-2 inhibitors. [2]

Additional research from the National Institutes of Health indicates that GLP-1 medications may be associated with lower ferritin levels and an increased risk of anemia, particularly in people who use these medications long-term for weight management. [3]

 

Individual Factors That Matter

Not everyone taking GLP-1 medications will develop iron deficiency, but certain factors may increase your risk:

Medical History: People with low iron stores, history of anemia, or conditions affecting iron absorption (like celiac disease or inflammatory bowel disease) may be more vulnerable.

Treatment Factors: Longer use, particularly at higher doses for weight management, may have a greater impact on iron absorption and intake.

Lifestyle Factors: Vegetarians, vegans, and those who already consume limited iron-rich foods may be at higher risk.

Biological Factors: Women, especially those who menstruate, have higher iron needs and may be more susceptible to deficiency.

 

Supporting Your Health on GLP-1s

Work with Your Medical Team

The most important step is maintaining open communication with your healthcare providers. Discuss your iron levels before starting GLP-1 therapy and consider regular monitoring, especially if you're using these medications for weight loss rather than diabetes management.

Your doctor may recommend baseline blood work, including a complete blood count, serum iron, ferritin, and total iron-binding capacity (a measure of iron transport in blood). Don't hesitate to contact your healthcare provider if you develop symptoms like unusual fatigue, weakness, or pale skin.

Consider working with a registered dietitian who understands both GLP-1 therapy and nutrition optimization. As one nutrition expert noted, "the goal of these medications isn't only to lose weight, but rather to help people make lifelong changes in nutrition and exercise." [4]

 

Focus on Iron-Rich Nutrition

When your appetite is suppressed, every bite counts nutritionally. Prioritizing iron-rich foods becomes especially important:

Heme Iron Sources (most easily absorbed):

• Lean red meat: 3.5 mg per 3-oz serving.
• Chicken liver: 11 mg per 3-oz serving.
• Sardines: 2.9 mg per 3-oz serving.
• Ground turkey: 1.6 mg per 3-oz serving.

Non-Heme Iron Sources (plant-based):

• Lentils: 6.6 mg per cup cooked.
• Spinach: 6.4 mg per cup cooked.
• Dark chocolate: 3.9 mg per 1 oz.
• Pumpkin seeds: 2.3 mg per 1 oz.

Enhancement Tips: Pair non-heme iron with vitamin C-rich foods like citrus fruits, bell peppers, or strawberries to boost absorption. Avoid drinking tea or coffee with iron-rich meals, as these can inhibit absorption.

 

Monitor Your Health Proactively

While research continues to emerge, you can take control of monitoring your iron levels and overall blood health. Tools like Ruby's Iron Score technology can help people on GLP-1 medications, offering regular monitoring between doctor visits. The app also includes circulation monitoring and wellness tracking features that can help you maintain a comprehensive view of your health while managing weight loss.

 

Conclusion

The relationship between GLP-1 medications and iron deficiency represents an important intersection of modern medicine and nutrition science. While these medications offer significant benefits for diabetes management and weight loss, understanding their potential impact on blood health empowers you to take proactive steps.

By working closely with your healthcare team, focusing on nutrient-dense foods, and monitoring your iron levels, you can optimize both your weight management goals and your overall health. Don't wait for symptoms to appear—regular monitoring and informed nutrition choices are your best defense against complications.

Take Action Today: Most importantly, discuss this information with your healthcare team to determine if iron monitoring is right for you. Then explore our iron-rich recipe blog posts for delicious meal ideas that maximize nutrition even with a smaller appetite, and consider monitoring tools like the Ruby app to track your iron levels between doctor visits. Share this article with others who might benefit from understanding this important health connection.

Remember: This information is for educational purposes and should not replace professional medical advice. Always consult with your healthcare provider about any concerns regarding your medications or health status.

 

References

[1] BMC Medicine. "Glucagon-like peptide-1 receptor agonist use is associated with lower blood ferritin levels in people with type 2 diabetes and hemochromatosis: a nationwide register-based study."

[2] JAMA Network Open. "Use of SGLT2 Inhibitors vs GLP-1 RAs and Anemia in Patients With Diabetes and CKD."

[3] National Institutes of Health. "GLP-1 Receptor Agonists and Nutrient Absorption."

[4] The Conversation. "As Zepbound dominates headlines as a new obesity-fighting drug, a nutritionist warns that weight loss shouldn't be the only goal."

[5] Trilliant Health. "2023 Trends Shaping the Health Economy Report."