Last Updated: September 3, 2026
Table of Contents
About Weight Loss Pills
Weight loss pills help to lose weight but eating less and moving more are the basics. For some people, prescription weight loss pills may help. You’ll still need to pay attention to diet and exercise while taking these pills; they’re not for everybody.
Doctors usually recommend them only if your BMI is 30 or higher or if it’s at least 27 and you have a condition that may be related to your weight, like type 2 diabetes or high blood pressure.
This Article Belongs to Weight Management
Medication and Treatment with Weight Loss Pills
The medication Semaglutide (Wegovy) received FDA approval to treat obesity in 2021. More common prescription weight loss pills which have been in use longer include Liraglutide (Saxenda), naltrexone-bupropion (Contrave), Orlistat (Alli, Xenical), phentermine (Adipex-P, Ionamin, Pro-Fast), and phentermine-topiramate (Qsymia).
Before you get a weight loss pills prescription, tell your doctor about your medical history. That contains any allergies or other conditions you have, medicines or supplements you take (even if they’re herbal or natural), and if you’re pregnant, breastfeeding, or scheduling to get pregnant soon. It is also important to discuss the benefits and risks of prescription weight-management medications with a qualified healthcare professional. The U.S. Food and Drug Administration (FDA) provides safety information about medications and potential side effects.
About Liraglutide (Saxenda)
How it Works:
Liraglutide, a higher type 2 diabetes drug Victoza dosage, mimics an intestinal hormone expressing your stomach full to the brain.
Side Effects:
Includes nausea, vomiting, diarrhea, constipation, and low blood pressure. Serious side effects can contain raised heart rate, pancreatitis, gallbladder disease, kidney problems, and suicidal thoughts. Studies have shown Liraglutide to cause thyroid tumors in animals, but it is not yet recognized if the drug can cause thyroid cancer in humans.
What Else You Should Know:
If you don’t lose 4% of your weight in 16 weeks of taking Liraglutide, your doctor may tell you to stop taking it or consider another treatment.
About Naltrexone HCl and Bupropion (Contrave)
How it Works:
Contrave is a mixture of two FDA-approved pills, naltrexone and bupropion, in an extended-release formula. Naltrexone is permitted to treat alcohol and opioid dependence, and bupropion is approved to treat depression and seasonal affective illness and help people stop smoking.
Side Effects:
The most common side effects include nausea, constipation, headache, vomiting, dizziness, insomnia, and dry mouth. Contrave has a boxed warning about the increased risk of suicidal thoughts and behaviors associated with bupropion. Contrave can also cause seizures and should not be used in patients with a seizure disorder. The pills can also raise blood pressure and heart rate.
What Else You Should Know:
If you do not lose 5% of your weight during the last 12 weeks of taking Contrave, your doctor may tell you to stop taking it because it is unlikely to work for you, according to FDA prescribing guidance.
About Orlistat (Xenical)
How it Works:
It stops your body from absorbing about a third of the fat you eat. When a doctor prescribes Orlistat, it’s named Xenical. If you can get it without a prescription, it’s Alli and has half the dose of Xenical.
Side Effects:
These can include abdominal cramps, bloating, leakage of oily stools, more bowel movements, and an inability to control bowel actions. These side effects are generally mild and temporary, although they can become worse if you eat high-fat foods.
Rare cases of severe liver damage have been reported in people taking Orlistat, but it is unclear whether the drug caused these problems.
What Else You Should Know:
It would help if you ate a low-fat diet, with less than 30% of your daily calories coming from fat, before taking Orlistat. You should also take a multivitamin at least 2 hours before or after taking Orlistat, as the drug temporarily makes it harder for your body to absorb vitamins A, D, E, and K.
Orlistat is the one drug of its kind approved in the United States. All other prescription weight loss drugs reduce appetite, including the following.
About Phentermine
How it works:
Phentermine curbs appetite. Your doctor may prescribe this under names that include Adipex or Suprenza. It is approved for short-term use, generally for a few weeks.
Side Effects:
These can be serious, such as high blood pressure or palpitations, restlessness, dizziness, tremors, insomnia, shortness of breath, chest pain, and difficulty with activities you could do before. Less serious side effects include dry mouth, unpleasant taste, diarrhea, constipation, and vomiting. As with other appetite suppressants, there is a risk of dependence on the pills.
Please do not take it late at night, as it can cause insomnia. If you are taking insulin for diabetes, tell your doctor before taking phentermine, as your insulin dose may need to be adjusted.
You should not take phentermine if you have heart disease, stroke, congestive heart failure, or uncontrolled high blood pressure. You must also not take it if you have glaucoma, an overactive thyroid, a history of substance abuse, or if you are pregnant or breastfeeding.
What Else You Should Know:
Phentermine is a stimulant and a controlled substance because of its potential for misuse and dependence. It should only be used under the direction of a qualified healthcare professional.
About Phentermine and Topiramate (Qsymia)
How it Works:
Qsymia curbs appetite by combining phentermine with topiramate, an anti-seizure and migraine medication. Topiramate can promote satiety, make food taste less appealing, and contribute to weight loss.
Qsymia is approved for continuous use at lower doses of phentermine and topiramate than when these medications are administered alone.
Side Effects:
The most common side effects are tingling in the hands and feet, dizziness, altered sense of taste, insomnia, constipation, and dry mouth.
Serious side effects include congenital disabilities such as cleft lip and palate, faster heart rate, suicidal thoughts or actions, and eye problems that can lead to permanent vision loss if left untreated.
Women who might become pregnant must take a pregnancy test before taking Qsymia, use contraception, and have monthly pregnancy tests done while taking the medication.
You should also not take Qsymia if you have glaucoma, hyperthyroidism, heart disease, or a history of stroke. Your healthcare provider may monitor your heart rate and adjust your treatment when necessary.
What Else You Should Know:
If you don’t lose at least 3% of your weight after 12 weeks on Qsymia, your doctor may recommend stopping treatment or increasing the dose for another 12 weeks. If treatment is discontinued, the medication may need to be tapered gradually.
About Semaglutide (Wegovy)
How it Works:
Semaglutide mimics a gut hormone that stimulates insulin production, reduces appetite, and makes you feel full.
Semaglutide was initially approved for the treatment of type 2 diabetes and is prescribed for that use under the names Ozempic and Rybelsus. Wegovy is specifically designed for chronic weight management and is used alongside a reduced-calorie diet and increased physical activity.
People interested in learning about other approaches to weight management can also explore the R3 weight loss program and consider how structured lifestyle changes may fit into an overall weight-management strategy.
Side Effects:
Side effects can include abdominal pain, constipation, vomiting, bloating, headache, fatigue, and gastroesophageal reflux. These side effects are usually mild and temporary. Kidney problems and changes in vision have occurred in some patients. Semaglutide has also been associated with pancreatitis. Get medical help promptly if you develop symptoms of pancreatitis, including severe stomach or abdominal pain and persistent nausea or vomiting.
What Else You Should Know:
Weight management with semaglutide may require long-term treatment, and stopping treatment can result in weight regain. It should be used together with a reduced-calorie diet and exercise program as recommended by a healthcare professional.
Weight loss can also change fat distribution throughout the body. For readers specifically interested in reducing fat around the legs and thighs, this guide on how to reduce thigh fat provides additional information about lifestyle approaches and body-contouring options.
Conclusion
Pharmacological weight loss interventions have demonstrated greater weight reductions in many people with obesity compared with lifestyle interventions alone. However, lifestyle interventions that combine diet, physical activity, and behavioral support remain an important part of successful long-term weight management.
Counseling and motivational interventions can also help people make sustainable lifestyle changes and achieve greater weight loss than simply receiving written information about diet and exercise. Even modest weight loss, such as 5% of initial body weight, can be associated with meaningful health benefits, including improvements in blood pressure, blood sugar, and other cardiovascular risk factors.
The degree of health benefits can vary depending on the amount of weight lost and a person’s overall health. Dietary approaches also differ from person to person. For example, evidence suggests that Mediterranean-style eating patterns can be beneficial for long-term cardiovascular health and may support weight-management goals.
Weight loss medications should not be viewed as a quick fix. They work best when combined with appropriate nutrition, physical activity, behavioral changes, and regular medical supervision. Readers interested in different weight-loss journeys can also learn more about Mark Anthony’s weight loss for another perspective on weight management.
