Common Questions About Weight-Loss Medications, Answered by a Mayo Clinic Expert

With the rising prevalence of obesity and related health conditions, many people are turning to weight-loss medications as a tool to support their health journey. But how effective are they? Who qualifies? And what happens after you stop taking them?

To help clarify these common concerns, Dr. Andres Acosta, M.D., Ph.D., an obesity researcher at Mayo Clinic and co-author of The Mayo Clinic Diet: Weight-Loss Medications Edition, shares expert insights on what patients should know before starting, continuing, or stopping prescription weight-loss medications.

Who Can Take Prescription Weight-Loss Medications?

Prescription obesity medications are typically recommended for individuals who:

Have a Body Mass Index (BMI) over 30 (classified as obese), or
Have a BMI over 27 with at least one obesity-related condition such as type 2 diabetes, hypertension, or sleep apnea.

Your healthcare provider will evaluate your overall health, medical history, and treatment goals before prescribing any medication.

How Do These Medications Work?

Most FDA-approved weight-loss drugs work by suppressing appetite and increasing satiety, helping people eat less and feel fuller longer. This caloric reduction leads to weight loss, especially when combined with diet and lifestyle changes.

What Should I Expect After Starting a Weight-Loss Medication?

In the early stages of treatment:

It’s common to see rapid weight loss in the first few weeks, mainly due to reduced calorie intake and water loss from the breakdown of glycogen stores.
You may experience side effects such as nausea, digestive issues, or headaches—these are often temporary but should be monitored.

💡 Tip: Don’t rush the weight loss. The ideal pace is 1–2 pounds per week, which typically results in more fat loss and better long-term maintenance.

Is Rapid Weight Loss Dangerous?

Yes, it can be. While a quick drop in weight may seem encouraging, losing weight too fast increases the risk of:

Muscle loss, which makes it harder to keep weight off
Nutrient deficiencies, leading to fatigue or hair loss
Regained weight once the body adapts or the medication is stopped

That’s why long-term weight-loss plans should include a focus on sustainable lifestyle changes.

How Long Will I Need to Take a Weight-Loss Medication?

The answer varies by individual and depends on:

✔️ Effectiveness

If the drug helps you lose weight (at least 5% of your body weight within 3–6 months) and the side effects are tolerable, your provider may recommend continuing even after reaching your goal weight.

✔️ Tolerance

If side effects are unmanageable, you and your healthcare team may adjust the dosage or switch to a different medication.

✔️ Administration

Many drugs require daily or weekly injections. If you struggle with needle phobia or skin reactions, proper training and technique are key.

✔️ Cost

Some medications can be expensive and not covered by insurance. Look for copay assistance or ask your provider about more affordable alternatives.

✔️ Health Changes

If your health status changes, your care team may advise pausing or discontinuing the medication.

What Happens When I Stop Taking Weight-Loss Medications?

When you stop the medication, lifestyle choices become even more important to maintain results. According to research, 90% of people who successfully maintain weight loss:

Exercise around an hour daily, including:
- Cardio for heart health
- Strength training at least twice per week to preserve muscle mass

Building and maintaining muscle is crucial because muscle tissue burns more calories than fat—even at rest.

Consistency with diet, movement, and healthy habits is the best long-term strategy.

Summary: Should You Consider a Weight-Loss Medication?

Weight-loss medications are not magic pills, but they can be powerful tools when paired with the right support system, diet, and exercise plan. If you meet the criteria and have struggled to lose weight through lifestyle changes alone, talking to your healthcare provider could be a life-changing step.

And remember, even if you eventually stop taking the medication, the Mayo Clinic Diet and similar programs offer structured, evidence-based strategies to help you stay on track.