What Are Weight Loss Medications?

Weight loss medications, sometimes also called weight loss drugs or anti-obesity medications, are prescription drugs that reduce your appetite and food cravings. Over the last few years, the FDA has approved a number of anti-obesity medications that help control appetite and food cravings.

Because weight loss drugs make you less hungry, they also reduce how many calories your body takes in each day. Over time, eating fewer calories will cause you to lose weight.

Some anti-obesity medications also help decrease cravings and control compulsive eating, especially for sweets and fatty, salty, high-calorie foods.

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What Do Doctors Prescribe for Weight Loss?

FDA-approved weight loss medications include the following:

Phentermine is a pill you take by mouth. It's a stimulant that has similar effects to amphetamines. It's an appetite supressant and has been on the market since the 1970s.

Lorcaserin (also called Belviq) is a weight loss pill that was approved by the FDA in 2012. It works by selectively targeting hunger receptors in your brain that researchers believe help you feel more full, and therefore help you eat less.

Topiramate/topomax is a pill that helps manage binge eating and encourage weight loss. Topiramate is an anticonvulsant drug, which means it belongs to a class of drugs that help treat seizures. You should take a low dose of this medicine. Some people also use it to prevent migraines.

Contrave (also called naltrexone HCL or bupropion HCL) is made up of two medications: naltrexone HCL and bupropion HCL. Naltrexone HCL is used to treat opiate addiction, and bupropion HCL is used to treat depression. Both of these medicines work together to lower your appetite and control some cravings.

Victoza (also called Liraglutide) is injected into your skin. When taken at a certain dosage, it helps lower your appetite and control some food cravings. It also lowers blood sugar levels in people who have diabetes.

Saxenda (also called Liraglutide) is an injection that helps people lose weight by lowering appetite and controlling food cravings. It uses the same active ingredient as Victoza, but you should not use these two medicines together. 

I'm Over 65. Can I Take Weight Loss Medications?

Your doctor may prescribe weight loss medications to you if you’re between the ages of 18—64. But there’s no evidence that weight loss medications work in adults over the age of 65.

How Much Weight Will I Lose?

By combining weight loss medications with diet and exercise, most people lose 7.5—22 pounds more than with diet and exercise alone. 

Health Benefits of Losing Weight

There are also positive health benefits to losing weight. Losing just five—10 percent of your body weight will lower your:

  • blood pressure,
  • lipid levels (fats), and
  • glucose (blood sugar).

Losing five to 10 percent of your body weight is a good starting goal for many patients.

Here are some facts around weight loss and health:

  • Losing just three—five percent of your body weight will lower your chances of getting heart disease.
  • High blood pressure is twice as common for obese adults than adults who aren't obese.
  • For every two pounds you gain, your chances of developing arthritis go up by nine to 13 percent.
  • For every two pounds you gain, this puts another four pounds of pressure your knees. Being overweight increases your chances of having knee pain.
  • Older people who are obese have lower muscles mass. This means they're more likely to fall and fracture bones.
  • People who are overweight have higher odds of dying or having serious complications during surgery.

How Quickly Do Weight Loss Medications Work?

Most people taking weight loss medications lose an average of one to two pounds per week. Of course, weight loss medications work best when you combine them with other healthy lifestyle changes like eating healthy foods and getting regular exercise.

Most patients start to lose weight within weeks. But if you can’t lose more than 5 percent of your body weight within 12 weeks, your doctor may stop prescribing these drugs and develop a different treatment plan for you.

Should I Combine Weight Loss Medications With Exercise?

Weight loss medications work best when you combine them with lifestyle changes like choosing healthier foods, eating fewer calories, and exercising regularly.

You will need to combine weight loss drugs with lifestyle changes if:

  • your BMI (body mass index) is more than 30kg/m2, or
  • your BMI is more than 27kg/m2 and you have a chronic disease like type 2 diabetes or high blood pressure (hypertension).

How Long Will I Need to Take Medication?

Depending on your health and weight loss goals, you may need to take weight loss medications for years. Because obesity is a chronic disease, the FDA has approved these drugs for long-term use.

Side Effects

Before you’re prescribed any anti-obesity medications, your doctor will ask for your entire medical history, including any: 

  • diseases you have;
  • what medications you take now; and
  • what medications you’ve taken in the past.
Your doctor will work with you carefully to make sure it’s safe for you to take weight loss medications along with any other medications you take.

Diabetes Medications & Weight Loss

Newer diabetes medications can also help people with diabetes lose weight. These medications work by controlling blood sugar (glucose) levels inside the body, which in turn helps people feel less hungry and more full.

These medications are called GLP1-agonists. They include:

  • liraglutide (Victoza, Saxenda),
  • lixisenatide (Lyxumia),
  • albiglutide (Tanzeum),
  • dulaglutide (Trulicity),
  • semaglutide (Ozempic), and
  • exenatide (Bydureon). 

Another type of diabetes medication called SLT2-inhibitors help people lose weight. These include:

  • dapagliflozin (Farxiga),
  • empagliflozin (Jardiance), and
  • canagliflozin (Invokana).