Prescription weight loss medications can help people with obesity lose weight. They are usually prescribed by a doctor when diet and exercise alone don’t work. Each of these medications works differently. People using these medications may not feel as hungry. Or they may feel full after eating only a small amount of food. Another type of weight loss medication makes it harder for the body to absorb fat. Prescription weight loss medications may be helpful when used in combination with a low-calorie diet and regular physical activity.
Who uses prescription medications to lose weight?
Prescription weight loss medications are only for obese people. Most of these medications are designed for people who weigh 20% or more above what is ideal for their height and body type. Or they are used with people who have a high body mass index (BMI). BMI is a measure of your weight in relation to your height. Your doctor may prescribe medications to treat your obesity if you have:
- A BMI of 30 or more.
- A BMI of 27 or more and you have a disease or condition that may be related to your weight (this could include diabetes or high blood pressure).
Your doctor can tell you if prescription weight loss medications might be helpful for you.
Path to better health
Prescription weight loss medications generally work in two ways. Most work on your body to make you less hungry or feel full faster. An FDA-approved medication works in the digestive tract. Blocks the amount of fat your body can absorb. Some medications are approved only for a short period of time, usually no more than 12 weeks. Others can be used long term.
The following are medications currently approved by the FDA for weight loss. Also included is information on how they work, common side effects, and warnings for each.
orlistate
- Brand Name: Xenical
- how it works: Reduces the amount of fat your body absorbs.
- Side effects: diarrhea, gas, uncontrollable bowel movements, loss of oily stools
- Warnings: It may reduce the amount of certain vitamins your body can absorb. You should take a multivitamin pill every day.
Orlistat is also available in lower doses without a prescription. That over-the-counter medication is called Alli. Orlistat is the only drug of its type approved in the US.
The following medicines will make you feel less hungry or feel full more quickly. They share common side effects, such as constipation, dizziness, dry mouth, diarrhea, and nausea. Additional side effects are listed for each medication.
Naltrexone-bupropion
- Brand Name: contravene
- How it works: It makes you less hungry or feel full faster.
- Side effects: headache, increased blood pressure and heart rate, insomnia, liver damage, vomiting
- Warnings: Do not use if you have untreated high blood pressure, seizures, or a history of anorexia or bulimia. Do not use if you rely on opioid pain relievers or are withdrawing from drugs or alcohol. Do not use it if you are already taking bupropion (brand names Wellbutrin, Zyban). This medication may increase suicidal thoughts or actions.
Phentermine-topiramate
- Brand Name: Qysmia
- How it works: It decreases appetite and makes you feel full sooner.
- Side effects: changes in taste (especially carbonated drinks), tingling in hands and feet, trouble sleeping
- Warnings: Tell your doctor if you have had a heart attack, stroke, abnormal heart rhythm, kidney disease, or a mood disorder. Do not take if you have hyperthyroidism or glaucoma. This medicine may cause birth defects. Do not use if you are pregnant, planning to become pregnant, or breastfeeding.
Liraglutide
- Brand Name: Saxenda
- How it works: It makes you feel less hungry or full sooner.
- Side effects: abdominal pain, headache, increased pulse
- Warnings: It is available only by injection. It could increase the chance of developing pancreatitis.
semiglutide
- Brand Name: Wegovy and Ozempic
- How it works: Regulate your appetite so you feel less hungry.
- Side effects: nausea, diarrhea, indigestion, headache
- Warnings: It’s an injection. Use of this medication may increase the risk of thyroid tumors.
There are other medications that can reduce your desire to eat. These include:
- Phentermine
- Benzphetamine
- diethylpropion
- phendimetrazine
These medications are only approved by the FDA for short-term use, up to 12 weeks. They may only provide temporary weight loss. They also have some side effects. These include:
- difficulty sleeping
- Feeling nervous or uneasy
- Headache
- Increased blood pressure or pulse
You should not use these medications if you have uncontrolled high blood pressure, heart disease, hyperthyroidism, or glaucoma. You should tell your doctor if you have anxiety or mood disorders before using these medications.
In rare cases, some weight loss medications can cause serious liver damage. Call your doctor right away if you notice symptoms of liver injury, including:
- itchy skin
- Yellow eyes or skin
- Brown or dark-colored urine.
- Pale colored stool
- Loss of appetite
- abdominal pain
Some weight loss supplements containing ephedra, ephedrine, or caffeine are available over the counter (without a prescription). It is not known if these medications are safe. These supplements have been linked to reports of heart attacks, seizures, strokes, and death. It is important to talk to your doctor if you are taking or considering taking an over-the-counter weight loss supplement.
Things to consider
How can I prevent weight gain again when I stop using the medication?
There is no easy cure for being overweight. Prescription weight loss medications can help you get off to a good start. But once you stop taking them, you may regain the weight you lost. To maintain your weight, you must eat a healthy diet and engage in regular physical activity. You should continue these healthy habits even after you stop taking the medication. Remember that losing weight and keeping it off is a lifelong endeavor.
How can I lose weight without taking a weight loss medication?
If you decide that weight loss medications are not right for you, you can still achieve your weight loss goals. It is important to develop healthy eating habits. But don’t expect to change everything overnight. Start by training yourself to eat without doing anything else at the same time. For example, don’t eat while watching television. Focus on what you are eating. Try to eat slowly.
Next, change what and how much you eat. Your doctor can help you create a low-calorie diet or low carb Diet plan that will help you lose weight. They can offer tips for healthy snacking and portion control.
It is also important to be physically active. Regardless of your weight loss goal, the minimum recommended exercise to improve health is 30 minutes 5 times per week (for a total of 150 minutes per week). Regular exercise helps you burn calories faster, even when you are sitting still. Exercise also helps you burn fat and build muscle.
Aerobic exercise increases your heart rate and helps you burn calories. Examples of aerobic exercises include swimming, brisk walking, jogging, and cycling. Anaerobic exercise, such as weight training, is also good because it adds muscle mass to your body. Muscle burns calories faster than fat.
Be sure to consult with your primary care doctor before starting an exercise program. They can help you create an exercise plan that will help you achieve your goals.
Questions to ask your doctor
- What is my BMI?
- Am I eligible to receive weight loss medications?
- What medication is right for me?
- What are the side effects?
- Are the risks and side effects worth the benefits of taking the medication?
- Will my insurance cover it?
- How long will I take it?
- Will I gain weight when I stop taking it?
- What can I do to avoid gaining weight?
Resources
Centers for Disease Control and Prevention: Healthy Weight, Nutrition, and Physical Activity
