From the Desk of Dr. Z
AgelessRx Co-founder and Chief Medical Officer, Dr. Sajad Zalzala, offers his insights on how GLP-1 medications work—and which patients should take extra precautions. With decades of experience in preventive and longevity-focused medicine, Dr. Z explains what every patient should know before starting Semaglutide or Tirzepatide.
Here’s what we’ll cover in this blog post:
- Who’s most at risk for GLP-1 side effects?
- The seven risk groups to watch
- Practical ways to reduce your risk
- When to consider alternatives or adjustments
GLP-1 receptor agonists like Semaglutide and Tirzepatide have become go-to treatments for sustainable weight loss and improved blood sugar control. But they aren’t without side effects.
Most patients experience mild digestive symptoms at the start, like nausea or slower digestion. For some, though, those symptoms can be more intense or even lead to complications.
So, who’s most at risk, and what can you do if you fall into one of these groups? Let’s break it down.
Who’s most at risk for GLP-1 side effects?
1. Adults Over 60
GLP-1 medications slow digestion, which can sometimes lead to dehydration, loss of muscle mass, and gastrointestinal distress—concerns that are more pronounced in older adults. Those over 60 should:
- Stay well hydrated
- Monitor for excessive muscle loss (sarcopenia) and bone loss
- Start at the lowest possible dose and adjust gradually
2. Individuals with a History of Gastrointestinal Issues
GLP-1 medications are known for causing nausea, vomiting, diarrhea, and constipation—especially during dose escalation. Those with conditions like the below may find that these medications worsen symptoms or become difficult to tolerate:
- Gastroparesis (delayed stomach emptying)
- GERD or acid reflux
- IBS or chronic constipation
3. Those with a Personal or Family History of Thyroid Cancer
GLP-1 receptor agonists carry a boxed warning for a rare type of thyroid cancer called medullary thyroid carcinoma (MTC). While the risk in humans is not fully established, those with a personal or family history of MTC or MEN2 syndrome should avoid GLP-1s.
See our blog on GLP-1 medications and thyroid cancer risks for more information.
4. Patients with a History of Pancreatitis
These medications have been linked to pancreatitis (inflammation of the pancreas) in some cases. If you have a history of pancreatitis, discuss alternative weight-loss options with your provider before starting a GLP-1.
5. Those Taking Certain Medications
GLP-1s slow digestion, which may alter how your body absorbs other medications. This is especially important for:
- Blood sugar-lowering medications (like insulin or sulfonylureas), which may increase the risk of hypoglycemia.
- Blood pressure medications, which may increase the risk of low blood pressure (especially with weight loss)
- Oral medications that require consistent absorption, such as thyroid medications, some antibiotics, and oral birth control
Always tell your prescriber about all the medications you’re taking before getting started, including over-the-counter treatments and supplements. Your AgelessRx prescriber will review your unique health history and medications to determine if a GLP-1 prescription is right for you.
6. People with Gallbladder Disease or a History of Gallstones
GLP-1s may increase the risk of gallbladder disease, gallstones, or even the need for gallbladder removal. If you’ve had gallbladder issues in the past, your doctor may recommend:
- Frequent monitoring for symptoms, including right upper abdominal pain and nausea
- Preventive measures, like staying hydrated and avoiding rapid weight loss
7. Those with a History of Depression
Though rare, some patients on GLP-1s have reported mood changes, depression, or suicidal thoughts. If you have a history of mental health conditions, you should:
- Monitor your mood closely
- Discuss any changes in mental health with your provider
What If You’re in a Higher-Risk Group?
If you fall into one of these categories, that doesn’t necessarily mean you can’t take Semaglutide, Tirzepatide, or Liraglutide—but you should proceed with extra caution. Your provider may:
- Start with a lower dose and increase more gradually
- Monitor you more frequently for side effects
- Recommend additional blood work or imaging to track progress
- Consider alternative medications or non-medication-based weight loss strategies
Bottom Line: Safety First
GLP-1 medications have helped many people achieve sustainable weight loss and improved metabolic health, but they’re not one-size-fits-all. If you’re considering Semaglutide or Tirzepatide, make sure to have a thorough discussion with your provider to weigh the benefits and risks based on your health history.
Note: The above statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.