How Do Prescription Weight Loss Medications Work?

Approximately 70% of American adults are obese or overweight, which is defined as having a body weight higher than normal due to excessive fat accumulation and lack of muscle mass. According to WHO (World Health Organization), being overweight is defined as a BMI of 25 or greater, and obesity is a BMI of 30 or more for adults. Being overweight or obese can put you at a higher risk of serious health problems such as diabetes, heart disease, stroke, and certain cancers. These health conditions are also some of the leading causes of death in the United States. The good news is that losing weight may reduce some of these risks while improving overall health. Studies show that losing just 5-10% of body weight can reduce the risk of cardiovascular diseases in obese or overweight adults.

Diet and exercise can help you lose weight; however, prescription weight-loss medications and lifestyle modifications are good options if exercise and diet do not result in adequate weight loss.

Please continue reading to learn more about the FDA-approved prescription and over-the-counter drugs for weight loss. We will discuss different prescription medicine options for weight loss and how they work.

How do prescription medications help you lose weight?

Most prescription weight loss medications target areas of the brain to decrease cravings, reduce appetite, and increase feelings of fullness—some medications, such as orlistat, work by interfering with fat absorption.

It is important to note that prescription medications for weight loss work along with diet and exercise. A healthy eating plan and regular exercise will help you maintain a healthy weight while improving your overall health. Different people may have different preferences for diets. Planning ahead is important to maintain healthy eating habits. A healthy diet does not always mean eating a low-calorie diet; a reduced-calorie diet with a regular exercise program will help you burn calories. However, keep in mind that losing weight should be achieved with a healthful mindset; for example, consuming fresh food and cooking with fresh ingredients will make you feel better since they are not packed with salt and preservatives. Mental wellness is also essential and can be achieved by incorporating meditation and yoga into your exercise routine.

What is the most effective weight loss prescription drug?

There are several effective prescription drugs available to help you achieve your weight loss goals. Your doctor will help you choose the best one based on your health history and personal preferences.

Here is some brief information on the prescription medications approved by the U.S. Food and Drug Administration (FDA) for chronic weight management.

Bupropion-naltrexone (Contrave)

This is an oral tablet taken twice a day by mouth. It is a combination medication containing naltrexone and bupropion. Naltrexone is used to treat addiction to alcohol and opioid pain medicines. Bupropion is used to treat depression and other mood disorders. Bupropion is also used for smoking cessation.

The two medications work together to control appetite. They act on the brain’s reward system to curb food cravings.

Possible side effects of bupropion-naltrexone (Contrave) include nausea, constipation, and headache. Contrave can cause uncontrolled high blood pressure. Other risks associated with the use of this weight loss pill include suicidal thoughts or actions.

Orlistat (Xenical and Alli)

Orlistat is available in a prescription-strength dose of 120 mg (brand name Xenical) to treat overweight and obesity. Over-the-counter medicines containing orlistat are also available (brand name Alli). OTC orlistat preparations contain a reduced strength (60 mg) of the drug. The dose is one tablet (Orlistat or Alli) with fat-containing meals three times a day.

Orlistat works by decreasing the absorption of fat from the intestines.

Possible side effects of orlistat include gastrointestinal symptoms like flatulence and loose stools. In rare cases, people taking orlistat can develop a severe liver injury. However, this adverse effect is rare and not well-supported.

Phentermine-topiramate (Qsymia)

This is a combination medication that contains phentermine (a weight loss drug) and topiramate (an anticonvulsant used to treat seizures). The brand name for this combination is Qsymia. Phentermine alone is available as Adipex-P and Lomaira. It is used for 12 weeks or less to help with weight loss.

Qsymia can regulate appetite and reduce caloric intake, thus helping you lose weight.

Possible side effects of phentermine-topiramate (Qsymia) include insomnia, nervousness, constipation, increased heart rate, and high blood pressure. Risks include the potential for abuse (phentermine acts like an amphetamine) and birth defects due to topiramate.

Liraglutide (Saxenda)

Liraglutide is an injectable medication. It belongs to a group of weight loss medicines called GLP-1 receptor agonists. This medicine is also used for diabetes management (available under the brand name Victoza).

Liraglutide (Saxenda) for weight management works by delaying gastric emptying and increasing feelings of satiety after meals. The starting dose is 0.6 mg subcutaneously (under the skin injection) once daily. The dose is increased gradually weekly to a maximum dose of 3 mg daily.

Common side effects of this obesity treatment include nausea and vomiting. This medicine can increase the risk of thyroid tumors.

Semaglutide (Wegovy)

This is a new drug treatment for obesity and overweight. Semaglutide is a GLP-1 agonist and is also used for the treatment of diabetes. It is available under the brand name Ozempic for diabetes management. Wegovy is the brand name of the semaglutide preparation used for weight management.

Wegovy (semaglutide) works by regulating appetite and food intake. It is an under-the-skin injection given once a week at a dose of 2.4 mg. Semaglutide is approved for use in adults with obesity or overweight and at least one weight-related chronic disease like type 2 diabetes, high cholesterol, or high blood pressure. As with all weight loss drugs, Wegovy (semaglutide) should be used in addition to a reduced-calorie diet and increased physical activity.

Possible side effects of semaglutide (Wegovy) include nausea, vomiting, diarrhea, abdominal pain, belching, gas, indigestion, headache, fatigue, and low blood sugar.

Boehringer Ingelheim and Zealand Pharma are developing a new injectable medication for obese and overweight patients with type-2 diabetes. In the same drug class as Saxenda and Wegovy (GLP-1 agonist), this novel medication (BI456906) is discovered to lead to “impressive” weight loss during phase 2 of the clinical trial.

Semaglutide (Wegovy) was being used as a comparator. Weight loss data for the highest tested dose of BI456906 (1.8 mg twice per week) was compared to the weight loss result of semaglutide (1 mg per week). With these dosing regimens at 16 weeks, BI456906 has been found to provide superior weight loss results compared to semaglutide (Wegovy). Though the research is still very early, this is exciting news for people who have type 2 diabetes and obesity or are overweight.

How do you qualify for prescription weight loss pills?

Your doctor may consider giving you prescription weight loss medications if you haven’t been able to lose weight through diet and exercise alone. You must meet the following criteria to qualify for weight loss medications approved by the FDA.

Have a body mass index (BMI) of more than 30 kg/m2.
Have a body mass index (BMI) of more than 27 kg/m2 and a serious obesity-related health issue like diabetes, high blood pressure, or high cholesterol.

How long does treatment last?

You may be able to take certain weight loss medicines indefinitely if you haven’t lost enough weight and you don’t have any serious side effects. However, if you have not lost at least 5% of your starting body weight after 3-6 months of obesity treatment or if you gain weight, your doctor will probably change you to another weight loss medicine.

How much weight can you lose in a month with Ozempic?

Ozempic (semaglutide) is sold under the brand name Wegovy for weight management. It is the newest among prescription weight loss drugs. In clinical trials, adults who took Wegovy for 68 weeks lost 35 lbs on average (15% of their body weight). This was compared to only 6 lbs of weight loss in people taking a placebo.

In general, you can expect to lose 3-7% more weight by taking prescription weight loss medications than you would with diet and exercise alone. Again, remember that you need a combination of lifestyle changes and weight loss medication to achieve weight loss.

Wrapping up

As mentioned above, a sustained weight loss of 5-10% can have significant health benefits, such as lowering blood sugar, blood pressure, and blood cholesterol levels and reducing your risk of cardiovascular disease, heart attack, and stroke.

However, in order to maintain this weight loss, lifestyle changes incorporating a low-fat diet and exercise are crucial.

You should discuss different options with your care teams since most of these medications require prior authorizations by your health insurance plans.

Some people gain some of the weight back when they stop taking weight loss medications. With that said, weight loss medicines can help to prevent weight gain and aid in dropping some stubborn pounds as you continue to work on adopting a healthy lifestyle.

Talk to your healthcare provider about which prescription weight loss drugs may be right for you. Also, talk to your doctor about whether you need other medications, dietary supplements, or a multivitamin pill during your treatment with weight loss drugs.

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