GLP-1 Medications Explained: What You Should Know

Updated on Sep 1, 2026 | Diabetes, Endocrinology, Featured, Heart Health, Popular, Vascular Health, Your Health

GLP-1 medications are now a major topic in health care and the news. These drugs can help people manage type 2 diabetes and lose weight. Researchers are also studying how they may help with other health problems.

What are GLP-1 medications? How do they work? What should you know about their benefits, side effects, and risks?

Reshmi Srinath, MD, Director of the Mount Sinai Weight and Metabolism Management Program, explains the basics of GLP-1 medications.

What are GLP-1 medications?

GLP-1 medications act like a natural hormone called glucagon-like peptide-1, or GLP-1.

The small intestine releases GLP-1. This hormone helps control blood sugar. It also helps people feel full after eating.

Researchers began studying gut hormones many years ago. They found that natural GLP-1 breaks down fast in the body. They later made forms that last longer and can be used as drugs.

Most GLP-1 drugs are peptides. Peptides are made from the same building blocks as proteins. Some newer drugs are not peptides. They can still target the same GLP-1 receptor in the body.

Reshmi Srinath, MD, Director of the Mount Sinai Weight and Metabolism Management Program

How do GLP-1 medications work?

GLP-1 medications affect several parts of the body. They can help:

  • Manage blood sugar: GLP-1 affects the pancreas and liver. Both help control blood sugar.
  • Help you feel full: The drugs can help people feel full after eating.
  • Slow digestion: The drugs slow the speed at which food moves through the digestive system.
  • Support weight loss: Feeling full longer can help people eat less and lose weight.

The first GLP-1 drugs were mainly used for type 2 diabetes. Doctors then noticed that with improvement in diabetes that many patients also lost weight.

Researchers are now studying other ways these drugs may help with other chronic health conditions, says Dr. Srinath.

What are the approved uses of GLP-1 medications?

The U.S. Food and Drug Administration (FDA) has approved GLP-1 medications for these uses:

  • Type 2 diabetes
  • Obesity and weight management
  • Obstructive sleep apnea
  • Heart disease
  • Metabolic dysfunction-associated steatohepatitis (MASH), a form of liver disease
  • Reducing certain heart and kidney risks in people with type 2 diabetes and kidney disease

Some GLP-1 drugs are shots, and some are pills. Not every drug is approved for every use. The table below lists approved drugs, key brand names, and uses*.

Active ingredient Key brand names FDA-approved uses
Semaglutide Ozempic, Wegovy, Rybelsus Type 2 diabetes; weight management; heart and kidney risk reduction; MASH
Tirzepatide Mounjaro, Zepbound Type 2 diabetes; weight management; obstructive sleep apnea; heart risk reduction
Liraglutide Victoza, Saxenda Type 2 diabetes; weight management; heart risk reduction
Dulaglutide Trulicity Type 2 diabetes; heart risk reduction
Orforglipron Foundayo Weight management

*Information accurate as of September 1, 2026.

What other uses are being studied?

Scientists are studying whether GLP-1 drugs may help with other health problems. Research includes:

  • Osteoarthritis
  • Autoimmune diseases, including some skin conditions
  • Cancer
  • Brain conditions, including Alzheimer’s disease and other forms of dementia

Why might one type of drug affect so many parts of the body? “There may not be one simple answer,” says Dr. Srinath.

Weight loss can improve some long-term health problems. Researchers are also studying how GLP-1 drugs may affect inflammation. Inflammation plays a role in many long-term diseases.

Scientists may find more ways these drugs can help. But more research is needed. We do not yet know if they are safe and effective for these other uses.

What are the most common GLP-1 side effects?

The most common side effects affect the digestive system. They include:

  • Nausea
  • Acid reflux
  • Constipation

Side effects may start soon after treatment begins. They often get better as the body gets used to the drug.

Side effects may come back when the dose goes up, says Dr. Srinath. Talk to your health care provider if they do not go away or worry you.

Are GLP-1 medications safe long term?

“GLP-1 medications are not brand-new drugs,” says Dr. Srinath.

These drugs have been used for diabetes for many years. Thousands of patients have also taken part in studies. Doctors have a large amount of information about their safety and side effects.

Still, newer GLP-1 drugs do not have decades of safety data. Researchers continue to study their long-term effects as more people use them.

Dr. Srinath says more long-term safety data is still needed. For now, she says the evidence is reassuring and the benefits outweigh any risks.

What are common concerns about GLP-1 medications?

As these drugs have become more popular, people have asked more questions about their effects. Here is what we know about some common concerns.

Are GLP-1 medications a “magic” weight-loss drug?

No. GLP-1 drugs can be strong tools, but a healthy lifestyle is also important, says Dr. Srinath.

Healthy eating and exercise still matter. Dr. Srinath recommends enough protein, fiber, and water each day. Limiting highly processed foods, sugary drinks, and alcohol can also help.

The drugs also do not work the same for everyone. Some people in clinical trials did not get the same results as others. GLP-1 drugs are not a guaranteed solution, says Dr. Srinath.

Do GLP-1 medications cause muscle loss?

Muscle loss is a common concern, especially when these drugs are used for weight loss.

“The bottom line is this: You are going to lose muscle no matter how you lose weight,” says Dr. Srinath.

About one-quarter of the weight a person loses may be muscle, while most of the rest is fat, says Dr. Srinath. She notes that muscle loss can happen with any type of weight loss, not just with GLP-1 medications.

Researchers are still studying what this muscle loss may mean. They do not yet know if it affects strength or how well a person can move.

For now, Dr. Srinath recommends staying active. She also recommends exercises that build and keep muscle. Getting enough protein is important too.

Can GLP-1 medications damage the heart?

Current data does not show that GLP-1 drugs damage heart muscle. In fact, some GLP-1 drugs have shown benefits for the heart, says Dr. Srinath.

Research is still underway. But current evidence does not suggest that muscle loss from these drugs weakens the heart.

Can GLP-1 medications affect your eyes?

Some studies have found a possible link to a rare eye problem. This problem affects blood flow to the optic nerve.

“That is an area of ongoing research, and while it is such a low risk, it is something I do tell patients about,” says Dr. Srinath. “I do think the benefits here outweigh any eye risks, though.”

Talk to your health care provider if you notice changes in your vision. You may also need to see an eye doctor.

Do not ignore new vision problems. Do not stop a prescribed drug before you talk to your health care provider.

What are compounded GLP-1 medications?

Some people use compounded GLP-1 drugs. These drugs may cost less and may be easier to get. They are often sold through compounding pharmacies and online health services.

Compounding pharmacies make drugs for individual patients. They do not supply the finished drug made by the original drug maker.

Compounded GLP-1 drugs are not the same as FDA-approved brand-name drugs, says Dr. Srinath. They do not go through the same FDA review for safety, quality, and how well they work.

Concerns about compounded GLP-1 drugs include:

  • The amount of active drug in a dose
  • The strength of the drug
  • Added ingredients, such as preservatives, vitamins, or supplements
  • Differences in quality between pharmacies

Dr. Srinath says some patients have received doses that were too strong or not strong enough. She says it can be hard to know how safe or effective a specific compounded drug may be.

Dr. Srinath recommends FDA-approved brand-name drugs when possible.

Cost and insurance coverage can make these drugs hard to get. This can lead some people to seek compounded drugs instead.

If you use a compounded GLP-1 drug, Dr. Srinath recommends care from a health care provider. This may be an endocrinologist, a weight management specialist, or a primary care provider.

Questions about GLP-1 medication? Schedule an appointment with a doctor

Should You Be Screened for Low Testosterone?

Aug 18, 2026 | Endocrinology, Your Health

Close up of a middle- aged Asian man looking away with his chin in his hand

Low testosterone happens when men cannot make normal amount of testosterone. While low testosterone happens gradually with age, certain conditions can cause it to happen earlier.

Men with low testosterone may benefit from testosterone replacement therapy (TRT) available through injections, gels, creams, and pills (which are not always covered by insurance).

Headshot of Michael Via, MD

Michael Via, MD

“For men who truly have low testosterone, TRT is generally a safe and effective treatment when prescribed and monitored appropriately,” says Michael Via, MD, a Mount Sinai endocrinologist.

In this Q&A, Dr. Via discusses who should be screened for low testosterone and the potential risks and benefits of TRT.

When should men be screened for low testosterone?

Testosterone levels naturally decrease as men get older, but the rate of decline varies from person to person. Because of this, routine screening for low testosterone is not recommended. It does not need to be part of your regular annual blood work.

However, if you are experiencing symptoms that could be related to low testosterone, talk with your doctor about whether testing is appropriate.

What are the symptoms of low testosterone?

The symptoms of low testosterone can be similar to many other common health concerns, so they are not always caused by low testosterone alone.

Common symptoms include:

  • Feeling more tired than usual
  • Muscle weakness or loss of strength
  • Low energy
  • Lower sex drive
  • Erectile dysfunction
  • Less facial or body hair growth

Some people also notice:

  • Trouble concentrating
  • Increased anxiety

These symptoms can have many different causes. If you are experiencing several of them, your doctor may recommend checking your testosterone level to see whether it could be contributing.

What can cause low testosterone besides aging?

Besides aging, several health conditions can lead to low testosterone.

  • Genetic conditions that affect testosterone production
  • Serious head injuries that damage the pituitary gland, a small gland in the brain that helps control hormone production. In many cases, testosterone levels return to normal within about a year without treatment
  • Metabolic syndrome: Conditions including excess weight around the waist; high blood pressure; high blood sugar; high triglycerides (a type of blood fat); and low HDL (“good”) cholesterol
  • Pituitary disorders, including pituitary tumors that produce excess prolactin, or large pituitary tumors that may need surgery can cause testosterone levels to be low. Both of these are uncommon, and your doctor can help guide evaluation

For many men, improving overall health may help restore the body’s natural testosterone production without testosterone replacement therapy. This would include:

  • losing weight
  • exercising regularly
  • eating a healthier diet
  • taking medications such as GLP-1 medicines when appropriate
  • having bariatric surgery

What are the benefits and risks of testosterone replacement therapy?

For men who have confirmed low testosterone and bothersome symptoms, testosterone replacement therapy may be appropriate.

In the right patients, TRT can improve symptoms, including better muscle strength, bone health, sexual function, and quality of life, but symptom improvement varies from person to person. Some men feel much better, while others notice little improvement.

The potential risks of testosterone replacement therapy include:

  • A reduction in your body’s own testosterone production
  • An enlarged prostate (benign prostate enlargement), which can worsen urinary symptoms in some men
  • An increase in red blood cells, which can make the blood thicker and may increase the risk of blood clots if blood counts become too high

Researchers have also studied whether testosterone therapy increases the risk of heart disease or prostate cancer. Current evidence has not shown an increased risk of major heart problems from testosterone therapy. The relationship between testosterone therapy and prostate cancer remains less certain, though current evidence suggests the risk may not be increased.

How long does testosterone replacement therapy treatment last?

Treatment is often a long-term commitment. In some cases, your doctor may recommend trying treatment for a few months and then stopping it to see whether it made a meaningful difference. Men already on TRT should continue regular follow-up with their doctor so they can monitor prostate health and blood counts.

Can testosterone replacement therapy improve my libido, energy, and mood?

Many men believe testosterone therapy will completely restore their energy, improve their mood, and solve every symptom they are experiencing. In reality, testosterone is not a cure-all. While it can be very helpful for men with confirmed low testosterone, it does not improve every symptom for every person.

Schedule an appointment with a Mount Sinai endocrinologist

Are Artificial Sweeteners Good for Me?

Updated on Aug 29, 2024 | Endocrinology, Your Health

Whether you prefer sugar substitutes in your coffee or enjoy artificially sweetened foods, you may wonder how these products affect your body, and if there are potential health risks.

David Lam, MD

In this Q&A, David Lam, MD, Medical Director of the Clinical Diabetes Institute at the Icahn School of Medicine at Mount Sinai, explains what the research says and how to use artificial sweeteners for weight loss.

What are the health benefits of using artificial sweeteners?

The only demonstrated health benefit of artificial sweeteners is they reduce your chances for developing cavities. These sweeteners have zero or very few calories, compared with sugar. However, for those who are looking to reduce their weight or control diabetes, the research is conflicting. There is some evidence that in the short term, there are some improvements in weight loss and glucose control, but the research is not definitive on whether artificial sweeteners help with weight loss in the long term.

What are the potential risks?

There are concerns about whether sugar substitutes increase your risk for cardiovascular complications and diabetes. However, for each study that shows an increased risk, another shows it’s not so defined. While the research so far is inconclusive, patients should be aware these questions exist.

One thing you do need to be wary of—the blanket terms “artificial sweeteners” and “sugar substitutes” are broad.

What are the different types of artificial sweeteners?

Sugar substitutes generally fall into three categories:

  • Synthetic sugars are made in laboratories and factories. Examples include Sweet’N Low® and Splenda®.
  • Sugar alcohols are often found in processed foods labeled as diet products. Despite the name, these products don’t contain actual alcohol. Unlike synthetic sugar, sugar alcohols can affect your blood sugar, so the marketing labels on these products (e.g., “sugar free”) may be misleading. Additionally, people who have underlying digestive problems may have a negative reaction to sugar alcohols, such as stomach upset and bowel movement changes.
  • Natural sugar substitutes, such as Stevia, are extracted from plants. These sugar substitutes are processed in laboratories and factories, but are essentially natural products, such as agave or honey.

How can I know if a food product contains sugar alcohol?

Sugar alcohols are usually found in diet products labeled “sugar free.” If you look at the food label and see ingredients ending in “ol” as in alcohol—such as sorbitol, xylitol, maltitol—it contains sugar alcohols.

Is there a way I can use artificial sweeteners for weight loss?

Artificial sweeteners are useful for weening yourself off added sugar and gradually adapting a wholefood diet. We know they are not effective long term. A doctor or dietician can guide you on how to create a long-term weight loss plan that works for you.  For example, a nutritionist can help you understand how to integrate whole fruits into your diet. While fruits contain sugar, they also contain fiber and other nutrients that are part of a wholesome diet, and can be a healthy substitute for processed snacks. Ultimately, there is no one perfect solution for weight loss. You need to weigh the pros and cons of artificial sweeteners on an individual level, and a health care professional can help you do that.

 

Concerned about your blood sugar and weight? Schedule an appointment with a primary care physician
Learn more about Your Health.

The Growing Problem of Diabetes: What Can We Do? (Part 3)

Updated on Jun 30, 2022 | Diabetes, Endocrinology

This post was written by Gerald Bernstein, MD, FACP, Director, Diabetes Management Program, Friedman Diabetes Institute at Mount Sinai Beth Israel.

In part 1 of this series, we looked at the overwhelming numbers of people with diabetes or prediabetes. In part 2, we looked at the critical role of structured education. Now, in part 3, we will look at a potential intervention.

Remember, over 40% of the US population over the age of 20 has either diabetes or prediabetes. Both are progressive stages of the same disorder and both have enormous risks attached to them. The solution to a problem of this enormity can best be approached by a partnership of private philanthropy, governmental support and institutional buy-in. (Although things may change, it does not look like there will be a federally mandated national diabetes program in the near future.) The underlying premise is that great institutions do great things.  (more…)

The Growing Problem of Diabetes — What Can We Do? (Part 2)

Updated on Jun 30, 2022 | Diabetes, Diet and Nutrition, Endocrinology

This post was written by Gerald Bernstein, MD, FACP, Director, Diabetes Management Program, Friedman Diabetes Institute at Mount Sinai Beth Israel.

It was the month of June 1959. I was in the last 30 days of my physician training internship, rotating through pediatrics. A 12-year old girl was admitted with type 1 diabetes mellitus. At that time, the only available tools for diabetes management were testing the urine for glucose and ketones. Other blood tests, including blood glucose, could take hours to perform. Insulin for injection consisted of mixed animal insulin (cows and pigs) and was much longer-acting and less predictable than the type we use today. The patient was a remarkable young woman and took things in stride.

(more…)

Diabetes No Match for Tennis Champions

Updated on Jun 30, 2022 | Diabetes, Endocrinology, Health Tips

When I was in high school in the late 1940s, I lived a few blocks away from the West Side Tennis Club. This was the home of the United States Championships, which ranked with those of Australia and Wimbledon. It was a different, more amateur era for tennis — players wore all white, including sneakers, and just as white were the tennis balls — yet the play was no less intense than that of today. Back then, there were no “tie breakers,” so matches could go on for hours — a challenge for any player with type 1 diabetes (once known as juvenile diabetes). (more…)