Obesity is more than just carrying extra weight. It is a medical condition that occurs when the amount of body fat directly affects your health. Since 2013, the American Medical Association has recognized obesity as a disease that can cause other illnesses, including heart disease, diabetes and more, all of which can shorten life expectancy.

For individuals with obesity, medications are now available to help weight loss; especially when combined with lifestyle modifications. It’s important to understand how those medications work, then you and your doctor can decide whether they’re right for you. 

Are there new medications for obesity?

Yes, new medications are now available to treat obesity. They are hormones that make us feel full. We naturally produce fullness hormones in our body that tell us to stop eating.

The new obesity medications prompt the body to respond similarly, but the effects from the medication last longer than natural hormones. So, not only do you feel full earlier in a meal, but you are satisfied for longer afterwards.

What are the names of these weight loss medications?

Currently there are two “fullness hormones” approved by the Food and Drug Administration for obesity management – Liraglutide (Saxenda) and Semaglutide (Wegovy). A third, known as Tirzepatide (Mounjaro), is not yet approved for obesity.

What exactly is a hormone?

Hormones are chemical messengers in our body. Medications for several conditions are hormonal, including thyroid hormone, insulin, and birth control pills. 

How do fullness hormones cause weight loss?

When you are taking hormonal medication for weight loss, you eat less without your brain noticing. You stop eating sooner and feel full longer. 

It sounds like portion control would do the same thing! How are medications different? 

To lose weight you must restrict how much you eat. But there is a catch! When you lose weight through portion control, your brain recognizes that you are eating less and takes action to fight back. It reduces your metabolism, increases your hunger hormone Ghrelin, and reduces your own fullness hormones. Hunger always wins! 

Also, you are likely to find it difficult to keep eating small amounts because your fullness hormone levels are low. On weight loss medication, your brain gets tricked. It thinks you are eating plenty of food because your fullness hormone level is high. You can eat less without the body fighting back. 

How much weight do you lose on hormonal weight loss medications?

Nearly all patients taking these hormonal weight loss medications lose at least five percent of their body weight in three months. If you are 240 pounds, that means a weight loss of 12 pounds.

Typically, about one-third of patients taking weight loss medications lose 15 to 20 percent of their body weight in one year. For that 240-pound individual that means a loss of between 36 and 48 pounds. The remaining two-thirds of patients will lose somewhere between five and 15 percent of their body weight. When taking these medications, the weight loss is slow and steady. 

Should I diet to help these medications?

No, “dieting” is not recommended when taking hormonal weight loss medications. Instead, I recommend eating when you are hungry and stopping when you are full. This is a mindful approach to eating, and takes practice, but will ensure you are responding to the desired effects of the medication.

Can I exercise on these medications?

Yes. Unlike strict dieting that can deplete your energy, you should have normal energy levels when taking hormonal weight loss medications. Exercise is considered part of a healthy lifestyle and is encouraged. 

Are these medications used to treat type 2 diabetes?

The names of these medications may sound familiar. Liraglutide, Semaglutide and Tirzeptide are used to treat diabetes under brand names: Victoza, Ozempic, and Mounjaro. If you have diabetes and obesity, you can also use these medications for treating both conditions.

If your insurance covers these medications without needing a prior authorization they can be used “off label” for obesity management, meaning your doctor can prescribe them for use other than that for which they have been approved. 

What are the risks of taking the weight loss medications?

Hormonal weight loss medications come with a black box warning on all these medications for a rare type of thyroid cancer. In addition, there are reports of kidney injury and a possible association with pancreatitis. You can talk to your doctor about what those risks might mean for you.

What are the common side effects from weight loss medications?

Like many medications, hormonal weight loss drugs carry a risk for side effects. The most common one is nausea. This side effect can be addressed by starting on a low dose of medication and increasing slowly as tolerated. Other reported side effects include constipation, diarrhea, and fatigue.

Does insurance cover weight loss medications?

Insurance does not always cover these medications, and unfortunately, the lack of coverage is related to the high cost of these medications. Before beginning a weight loss medication, talk with your doctor and check with your insurance to determine if your plan covers this medication. 

For more information on how we can help you with obesity, visit our website

Sheenagh Bodkin, MD

Dr. Sheenagh Bodkin is director of obesity medicine for the Center for Bariatric Surgery at The Miriam Hospital.