Weight Loss Drugs: What to Know Before Starting

GLP-1s and other weight-loss drugs have been all over the news in recent years. Chances are you know someone who is taking one, or you may be wondering whether one could be right for you.

Losing weight through nutrition and exercise alone can be challenging, especially when biological and medical factors are involved. Prescription weight-loss medications may offer another treatment option, but choosing one is a personal medical decision that should be made with a healthcare professional.

Dr. Aruna Venkatesh, an endocrinologist at University Health Texas Diabetes Institute, shares insight into how these medications work and answers frequently asked questions about their benefits and side effects.

What is a weight-loss drug?

Weight-loss drugs are prescription medications that can help people m anage obesity or excess weight. GLP-1 medications are among the most commonly discussed options, but the medication name and brand matter because products with similar ingredients may be approved for different conditions.

Semaglutide is the active ingredient in Ozempic, Wegovy and Rybelsus. Ozempic and Rybelsus are primarily used to treat Type 2 diabetes, while Wegovy is approved for chronic weight management in eligible patients. Tirzepatide is sold as Mounjaro for Type 2 diabetes and Zepbound for chronic weight management. Liraglutide is sold as Victoza for Type 2 diabetes and Saxenda for chronic weight management.

Some medications can reduce appetite, help people feel full sooner and slow digestion. Other prescription weight-loss drugs work differently, such as by affecting appetite, cravings or fat absorption.

What should people know before starting weight-loss drugs?

Before starting weight-loss medications such as GLP-1s, people should understand how the drugs work, what results to expect, the potential risks and the importance of medical supervision.

These medications aren't right for everyone. Your primary care provider should review your medical history, current medications and weight-related health conditions to determine whether treatment is appropriate.

Be prepared for side effects
Nausea, vomiting, diarrhea, constipation and abdominal discomfort are common, especially when starting treatment or increasing the dose. More serious complications can include gallbladder problems, pancreatitis and dehydration. Ask your doctor which symptoms require immediate medical attention.

If you have diabetes and take insulin or certain other diabetes medications, your risk of low blood sugar may increase when they are combined with a weight-loss medication. Your doctor may need to adjust your regimen.

Have a long-term plan
Obesity is a chronic condition, and stopping medication often leads to increased appetite and weight regain. Discuss how long treatment may last, how you will maintain progress and whether you can afford the medication over time.

Knowing the basics is only part of the decision. Daily habits and careful monitoring can make treatment safer and help support lasting results.

What do doctors recommend when taking weight-loss drugs?

Do:

• Follow your prescribed dosing schedule and prescriber’s instructions. These medications are typically started at a low dose and gradually increased to minimize side effects.
• Eat balanced, nutrient-rich meals. Prioritize protein, vegetables, fruits, whole grains and other nutrient-dense foods. Because appetite may decrease, it is important to get enough protein and essential nutrients to preserve muscle and support overall health.
• Stay hydrated. Nausea, vomiting and diarrhea can cause dehydration, particularly when food and fluid intake decline.
• Incorporate physical activity. Regular exercise, including strength training when appropriate, can help preserve muscle mass during weight loss.
• Communicate with your healthcare team. Report persistent side effects, discuss other medications you take and keep follow-up appointments to monitor your progress and overall health.

Don't:

• Don’t increase your dose on your own. Taking more medication or increasing the dose sooner than directed will not necessarily produce better results and can increase the risk of serious side effects.
• Don’t ignore severe symptoms. Seek prompt medical attention for severe or persistent abdominal pain, repeated vomiting or inability to keep fluids down. Severe abdominal pain can be a sign of pancreatitis or another serious complication.
• Don’t routinely skip meals or severely restrict calories. Reduced appetite can make it easy to undereat, potentially leading to inadequate nutrition and muscle loss.
• Don’t combine weight-loss medications without medical guidance. Tell your primary care provider about all prescription drugs, over-the-counter products and supplements you use.
• Don’t assume you can stop treatment without a plan. Appetite and weight may increase after discontinuation. Discuss maintenance strategies with your clinician before stopping.

Beware of unapproved or unverified weight-loss products

People should avoid buying injections from unverified online sellers or using products marketed as research chemicals. Products with uncertain ingredients, concentration or dosing can pose serious health risks. Be especially cautious of products marketed as the same medication at unusually low prices.

Do weight-loss drugs have any other health benefits?

Weight loss may be the primary goal, but some medications can offer other health benefits for certain patients.

Better blood sugar control
GLP-1 medications help regulate blood sugar and are used to treat Type 2 diabetes. They stimulate insulin release when blood sugar is elevated and help reduce blood sugar levels. Some patients may also need adjustments to their other diabetes medications.

Lower risk of cardiovascular problems
Some GLP-1 medications have been shown to reduce the risk of major cardiovascular events, such as heart attack and stroke, in certain patients. For example, semaglutide has demonstrated cardiovascular benefits in people with established cardiovascular disease and overweight or obesity.

Improved kidney health
Semaglutide has demonstrated benefits in people with Type 2 diabetes and chronic kidney disease, including reducing the risk of certain major kidney and cardiovascular outcomes. This is particularly important because diabetes, obesity and kidney disease frequently occur together, a condition called cardio-kidney-metabolic syndrome.

Improvement in obstructive sleep apnea
Tirzepatide (Zepbound) is FDA-approved to treat moderate to severe obstructive sleep apnea in adults with obesity. Weight loss can reduce the severity of sleep apnea, and clinical trials found improvements in patients treated with the medication.

Lower blood pressure and improved cholesterol levels
Weight loss can improve blood pressure and triglyceride levels, reducing some risk factors for cardiovascular disease. The degree of improvement varies, and patients may still need medication to manage blood pressure or cholesterol.

Less joint pain and improved mobility
Losing excess weight can reduce stress on weight-bearing joints, particularly the knees. This may help people with obesity and knee osteoarthritis experience less pain and move more comfortably.

Does someone have to stay on weight-loss drugs to keep the weight off?

The potential benefits also raise an important long-term question: What happens if treatment ends? In many cases, people need to continue treatment to keep the weight off.

People regain some of the weight they lost after stopping GLP-1 medications, although the amount varies from person to person. These medications treat the biological processes that contribute to obesity, including appetite and feelings of fullness. When treatment stops, those effects often diminish.

What happens when someone stops taking them?

• Appetite may increase. People may feel hungry more often and find it harder to feel full.
• Weight often returns. In a follow-up study of people who stopped semaglutide after 68 weeks of treatment, participants regained about two-thirds of their previous weight loss over the following year, on average.
• Health benefits may diminish. Improvements in blood sugar, blood pressure and other measures can fade as weight returns, although the extent depends on the individual and the condition being treated.
• Not everyone regains the same amount. Some people maintain a portion of their weight loss, particularly with sustained lifestyle changes and ongoing support.

People may not need to take these drugs for life, but many may need long-term treatment to maintain the full benefit. Because obesity is a chronic condition, much like high blood pressure or Type 2 diabetes, it can require ongoing management.

Some people may transition off medication successfully, but it helps to have a plan with their primary care team that addresses nutrition, physical activity, muscle preservation, appetite changes and weight monitoring. Others may need continued medication or a different treatment approach.

Because the risks and benefits vary, these medications are not appropriate for everyone. Your doctor can help identify when another approach may be safer.

Who should not take weight-loss drugs?

People who are pregnant or planning to become pregnant
Weight-loss medications are not intended for use during pregnancy. Losing weight during pregnancy offers no benefit that justifies the potential risks, and some medications must be stopped well before a planned pregnancy. For example, semaglutide is generally discontinued at least two months before a planned pregnancy.

People with certain thyroid cancer risks
Semaglutide and tirzepatide carry warnings against use in people with a personal or family history of medullary thyroid carcinoma, or a condition called multiple endocrine neoplasia syndrome type 2 (MEN2). These are specific thyroid cancer risks, not a blanket restriction for everyone with thyroid disease.

People who have had a serious allergic reaction to the medication
Anyone with a known serious hypersensitivity to a medication or its ingredients should not take that product.

People with certain serious or unstable medical conditions
A clinician should carefully evaluate people with a history of pancreatitis, gallbladder disease, severe gastrointestinal problems or significant dehydration. These conditions do not automatically rule out all GLP-1 medications, but they can affect treatment choice and the level of monitoring required.

People taking medications that could interact with weight loss drugs
Some weight-loss medications are unsuitable for people taking certain antidepressants, opioids or other drugs. GLP-1 medications can also affect how quickly the stomach empties, which may matter for people taking certain oral medications. A clinician or pharmacist should review all prescriptions, over-the-counter medications and supplements.

People seeking to lose a relatively small amount of weight for cosmetic reasons
Prescription weight-loss medications are intended for people who meet medical eligibility criteria, not simply for anyone who wants to be thinner. For many adults, eligibility begins at a BMI of 30 or higher, or 27 or higher with a weight-related health condition.

How do I start weight-loss medication?

Start by scheduling an appointment with your primary care provider and having an honest conversation about your weight-loss challenges, health history and the lifestyle changes you have already tried. If nutrition, physical activity and other healthy habits have not led to the results you hoped for, your provider can look for underlying health issues, review the medications you take and determine whether a prescription weight-loss medication may be appropriate for you.

If you also need help managing diabetes and weight loss, the team at University Health Texas Diabetes Institute offers coordinated support and resources, including dietitians, an on-site gym, workout classes and additional services designed to help you build sustainable habits. Learn more about our diabetes services at Texas Diabetes Institute.