GLP-1 Medications for Weight Loss: How to Get Started

If you’re considering a prescription weight-loss medication like Wegovy or Zepbound, the first question is often a practical one: Where do I start—and with whom?

The short answer: You can begin with your primary care clinician, a specialist in obesity medicine, or in some cases a telehealth provider. What matters most is that the prescribing clinician has experience managing obesity as a chronic disease and can follow you over time.

GLP-1 medications—short for glucagon-like peptide-1 receptor agonists—are prescription drugs that help regulate appetite, slow digestion, and improve blood sugar control. For weight management, the Food and Drug Administration (FDA) has approved two medications:

• Semaglutide (Wegovy)
• Tirzepatide (Zepbound)

These drugs contain the same active ingredients as diabetes medications such as Ozempic and Mounjaro, but Wegovy and Zepbound are specifically approved for chronic weight management.

GLP-1 medications are approved for adults who have a body mass index (BMI) of 30 or higher, or a BMI of at least 27 plus a weight-related medical condition, such as the following:

• Type 2 diabetes
• High blood pressure
• High cholesterol
• Obstructive sleep apnea
• Cardiovascular disease that increases the risk of heart attack or stroke
• MASH, or metabolic dysfunction–associated steatohepatitis, a form of liver inflammation

Avlin Imaeda, MD, PhD, a Yale Medicine gastroenterologist who is board-certified in obesity medicine, notes that qualifying for the medication based on heart disease alone—often necessary for insurance coverage—can be challenging.

“You have to have had a heart attack or stroke or have significant peripheral vascular disease in order for it to be approved,” Dr. Imaeda says.

According to FDA guidance, GLP-1 medications are not recommended for people who have:

• Pregnancy, because safety data are limited and pregnancy requires appropriate weight gain and nutrient storage
• A prior history of pancreatitis, due to a risk of triggering inflammation of the pancreas
• A history of medullary thyroid carcinoma or multiple endocrine neoplasia syndrome type 2 (MEN2), a rare genetic condition linked to thyroid cancer in animal studies

A clinician will review your medical history carefully to determine whether these medications are appropriate for you.

Any licensed health care provider—including primary care physicians, nurse practitioners, physician assistants, and specialists such as endocrinologists, cardiologists, and gastroenterologists—can prescribe GLP-1 medications.

Ideally, the prescriber is someone you can work with long term, says John Morton, MD, MPH, chief of Bariatric and Minimally Invasive Surgery at Yale Medicine and a board-certified obesity medicine specialist.

“That’s because obesity is a chronic disease,” Dr. Morton says. “It didn’t happen overnight and it’s not going to get better overnight. You don’t want to get a prescription and walk away—that’s not going to work in the long term.”

About half of patients who start a GLP-1 medication stop within a year, he notes, often because of side effects, cost, or lack of follow-up. Ongoing support improves adherence and outcomes.

The Yale Center for Weight Management, a collaboration between Yale New Haven Health and Yale School of Medicine, brings together obesity medicine specialists across cardiology, gastroenterology, endocrinology, and orthopaedics, along with dietitians, psychologists, and exercise physiologists.

“While primary care physicians are getting more comfortable prescribing these medications, we have a whole clinic built around it,” Dr. Imaeda says. “We can offer support around diet, exercise, and side effect management that primary care may not always have time to address. But what matters most is what’s best for the patient.”

Telehealth companies also prescribe GLP-1 medications, though continuity of care and long-term follow-up vary by provider.

Once a clinician determines that you’re a candidate—based on your medical history, physical exam, potential side effects, and insurance coverage—the next step is starting the medication gradually.

GLP-1 drugs commonly cause nausea, constipation, or an uncomfortable sense of fullness, especially early on, because they slow digestion. To reduce side effects, clinicians typically begin at the lowest dose and increase slowly.

“The fastest we increase the dose is once a month,” Dr. Imaeda says. “If after a month someone isn’t having significant side effects and isn’t losing weight too quickly, then I’ll increase the dose.”

Both medications are given as once-weekly injections using prefilled pens. A higher-dose oral (pill) form of semaglutide is also now available for daily use.

In most cases, yes. Research shows that people who stop GLP-1 medications after losing weight often regain a significant portion of it.

In one clinical trial, people who stopped tirzepatide (Zepbound) regained about 14% of their body weight over the following year, while those who continued treatment lost additional weight. Other data suggest that more than 80% of people regain at least a quarter of the weight they lost within a year of stopping.

“It might take a year to lose the weight, but only four months to gain it back,” Dr. Morton says. “It’s like a rubber band—you pull it hard and it snaps back quickly.”

For that reason, clinicians typically counsel patients that GLP-1 medications are a long-term treatment, similar to medications for high blood pressure or diabetes.

“If you stop taking your blood pressure medicine, what do you think happens?” Dr. Morton says.

Some people decide they don’t want to stay on medication indefinitely. If that’s the case, clinicians recommend not stopping abruptly.

“Talk to a professional about how to transition off,” Dr. Morton says. “That might mean focusing more on lifestyle changes, switching medications, or considering bariatric surgery.”

For some patients, surgical options such as sleeve gastrectomy may be appropriate, particularly if they want a more durable intervention.

Dr. Morton also emphasizes that weight regain is not a personal failure.

“People think they should be able to control this with willpower,” he says. “If they can’t, they think something is wrong with them. But obesity is driven by biology. It’s very hard to fight biology—and we have to change how we think about that.”