8 Prescription Weight Loss Drugs That Work Fast

Struggling to lose weight even with a balanced diet and regular exercise? It’s a common problem. For some individuals, prescription weight loss drugs can offer extra assistance to support their lifestyle modifications. While no “magic pill” exists for easy weight loss, several FDA-approved medications have shown positive results when used properly.

This article will focus on the top weight loss medications that have shown promising outcomes in scientific investigations. We’ll explain the workings of each medicine, the individuals who can benefit from them, and the potential side effects to keep in mind. Moreover, we’ll stress the crucial role of combining these medications with a healthy lifestyle, including a balanced diet and regular exercise.

Weight loss drugs are not a one-size-fits-all solution, and it’s essential to discuss the possible benefits and risks with your physician. However, for some people, prescription medicines can offer the extra support they need to achieve and maintain a healthy weight. Let’s take a closer look at the top 8 doctor prescribed weight loss medication available today.

8 Prescription Weight Loss Medications That Really Work

In this section, we will explore the top 8 strongest weight loss prescription drugs available in the market. Each drug will be discussed in detail, including its ingredients, benefits, mechanism of action, dosages, and side effects.

1. Wegovy – A Leading Prescription Weight Loss Medication

Ingredients: Semaglutide

Benefits: Wegovy stands out as one of the most effective prescription drugs on the market. It’s a once-a-week injection that significantly aids in weight loss by making you feel less hungry and more satisfied with smaller meals. This approach, combined with eating fewer calories and getting more exercise, makes Wegovy a top pick among the anti-obesity drugs approved by the FDA in 2024. It’s especially popular among doctors who prescribe weight loss medications to help their patients achieve their weight goals.

How it Works: The magic behind Wegovy is semaglutide, which acts like a hormone in your body that controls how hungry you feel. By mimicking this hormone, Wegovy helps manage your appetite, encouraging you to eat less and thus supporting your weight loss journey. This mechanism places Wegovy among the most potent anti-obesity medications available.

Doses: Wegovy treatment starts with a small dose of 0.25 mg once a week. Over 16 weeks, this dose is gradually increased to reach a maintenance dose of 2.4 mg. This gradual increase helps your body adjust to the medication smoothly.

Side Effects: Like all weight loss medications, Wegovy can cause side effects. These may include nausea, diarrhea, vomiting, constipation, abdominal pain, headache, fatigue, dyspepsia (indigestion), dizziness, abdominal distension (bloating), eructation (burping), hypoglycemia (low blood sugar) in people with type 2 diabetes, flatulence (gas), gastroenteritis (stomach flu), and gastroesophageal reflux disease (acid reflux).

2. Saxenda or Victoza – Effective Injectable Medications for Overweight and Obesity

Ingredients: Liraglutide

Benefits: Saxenda and Victoza are injectable prescription weight loss medications containing liraglutide, a GLP-1 receptor agonist. These medicationshelp reduce appetite and increase feelings of fullness. While Saxenda is specifically approved for weight management, Victoza is primarily used to treat type 2 diabetes but may also lead to weight loss.

How it Works: Liraglutide, the active ingredient in these medications, works similarly to semaglutide by mimicking the effects of the hormone GLP-1, which regulates appetite and food intake.

Doses: Saxenda is administered once daily via subcutaneous injection, with a starting dose of 0.6 mg and gradually increasing to the maintenance dose of 3.0 mg. Victoza is also administered once daily, with doses ranging from 0.6 mg to 1.8 mg, depending on the patient’s needs and tolerability.

Side effects: When taking these weight loss drugs, you might experience some common side effects like feeling sick to your stomach, having diarrhea or constipation, throwing up, having low blood sugar, getting headaches, feeling less hungry, having indigestion, feeling tired or dizzy, having belly pain, or having higher levels of a substance called lipase in your blood.

3. Invokana or Farxiga – Oral Medications for Weight Loss and Type 2 Diabetes

Ingredients: Canagliflozin (Invokana) or Dapagliflozin (Farxiga)

Benefits: Invokana and Farxiga are oral prescription drugs for weight loss that belong to a class called sodium-glucose cotransporter 2 (SGLT2) inhibitors. They are primarily used to treat type 2 diabetes but may also lead to weight loss by increasing the amount of glucose excreted in the urine.

How it Works: SGLT2 inhibitors work by blocking the reabsorption of glucose in the kidneys, leading to increased glucose excretion in the urine and lowering blood sugar levels. This process may also result in calorie loss and weight reduction.

Doses: Invokana is typically taken once daily, with a starting dose of 100 mg and can be increased to 300 mg if needed. Farxiga is also taken once daily, with a recommended dose of 5 mg or 10 mg.

Side effects: Common side effects of these weight loss medications include genital yeast infections, urinary tract infections, increased urination, constipation, nausea, and thirst. Rare but serious side effects may include dehydration, kidney problems, diabetic ketoacidosis (DKA), and amputation.

4. Naltrexone – An Opioid Antagonist for Weight Management

Ingredients: Naltrexone hydrochloride

Benefits: Naltrexone is an opioid antagonist primarily used to treat alcohol and opioid dependence. However, when used in combination with bupropion (another medication), it has been shown to help with weight loss by reducing appetite and cravings.

How it Works: Naltrexone works by blocking the effects of opioids in the brain, which may help reduce cravings and appetite. When combined with bupropion, it is thought to have a synergistic effect on weight loss.

Doses: Naltrexone is typically prescribed in combination with bupropion as a medication called Contrave. The recommended dose of Contrave is two tablets taken twice daily, with each tablet containing 8 mg of naltrexone and 90 mg of bupropion.

Side effects: While using Naltrexone, a prescription weight loss pill, individuals frequently report side effects like nausea, headache, dizziness, insomnia, vomiting, and constipation. Rarely, serious side effects of Naltrexone, such as liver damage, depression, and suicidal thoughts, may occur.

5. Metformin – An Oral Medication for Type 2 Diabetes and Weight Management

Ingredients: Metformin hydrochloride

Benefits: Metformin is an oral medication primarily used to treat type 2 diabetes. It may also lead to weight loss by reducing the amount of glucose absorbed from food and improving insulin sensitivity.

How it Works: Metformin works by decreasing glucose production in the liver, reducing glucose absorption in the intestines, and improving insulin sensitivity in the body.

Doses: Metformin is typically taken two to three times daily with meals. The starting dose is usually 500 mg twice daily, which can be gradually increased up to 2000 mg per day, depending on the patient’s needs and tolerability.

Side effects: Metformin, a medication commonly prescribed for weight loss, can cause various side effects, primarily affecting the digestive system. These include diarrhea, nausea, vomiting, bloating, gas, and stomach pain. Some users may also experience neurological symptoms such as dizziness and headaches, as well as muscle pain and taste disturbances. While these side effects often subside over time, patients can minimize their occurrence by taking metformin with meals and gradually increasing the dosage under medical supervision. In rare cases, metformin may cause lactic acidosis, particularly in patients with kidney issues. Switching to metformin extended release may help alleviate some of these side effects.

6. Phentermine – Prescription Weight Loss Pills that Work

Ingredients: Phentermine hydrochloride

Benefits: Phentermine is an appetite suppressant that helps with weight loss by reducing hunger and increasing feelings of fullness. It is one of the most commonly prescribed pills for weight loss.

How it Works: Phentermine works by stimulating the release of neurotransmitters in the brain, such as norepinephrine, dopamine, and serotonin, which help to reduce appetite and increase energy levels.

Doses: Phentermine is typically prescribed as a 37.5 mg tablet taken once daily in the morning, either with or without food. Some patients may be prescribed a lower dose of 18.75 mg or a higher dose of 56.25 mg, depending on their needs and tolerability.

Side effects: Phentermine, a prescription medicine, can cause various side effects. The most common ones include dry mouth, constipation, insomnia, dizziness, fatigue, irritability, headache, increased heart rate and blood pressure, and nervousness or restlessness. Less common side effects may include diarrhea, unpleasant taste in the mouth, vomiting, skin rash or itching, and changes in sex drive or impotence. In rare cases, phentermine can cause serious side effects such as chest pain, shortness of breath, swelling in the legs, severe headache, pounding heartbeat, lightheadedness or fainting, difficulty performing usual activities, weakness on one side of the body, slurred speech, and blurred or changed vision. If any of these serious side effects occur, seek medical attention immediately.

7. Qsymia – A Combination Medication for Effective Weight Loss

Ingredients: Phentermine hydrochloride and topiramate extended-release

Benefits: Qsymia is a combination medication containing phentermine and topiramate. It helps with weight loss by suppressing appetite, increasing feelings of fullness, and potentially increasing metabolism.

How it Works: Phentermine works as an appetite suppressant by stimulating the release of neurotransmitters in the brain, while topiramate is an anticonvulsant that may help with weight loss by increasing feelings of fullness and improving taste satisfaction.

Doses: Qsymia comes in four different dose strengths: 3.75 mg phentermine/23 mg topiramate, 7.5 mg phentermine/46 mg topiramate, 11.25 mg phentermine/69 mg topiramate, and 15 mg phentermine/92 mg topiramate. The recommended starting dose is 3.75 mg phentermine/23 mg topiramate once daily in the morning, which can be gradually increased based on the patient’s needs and tolerability.

Side effects: Qsymia’s common side effects include numbness, dizziness, taste changes, insomnia, constipation, and dry mouth. Serious side effects may include increased heart rate, suicidal thoughts, eye problems, mood changes, low blood sugar, metabolic issues, cognitive impairment, and seizures. Qsymia can cause severe side effects during pregnancy and is not recommended for patients with certain pre-existing conditions.

8. Contrave – A Combination Medication for Reducing Appetite and Cravings

Ingredients: Bupropion hydrochloride and naltrexone hydrochloride

Benefits: Contrave is a combination medication containing bupropion and naltrexone. It helps with weight loss by reducing appetite and cravings.

How it Works: Bupropion is an antidepressant that may help with weight loss by increasing dopamine and norepinephrine levels in the brain, while naltrexone is an opioid antagonist that may help reduce cravings and appetite.

Doses: Contrave is typically prescribed as two tablets taken twice daily, with each tablet containing 8 mg of naltrexone and 90 mg of bupropion. The recommended starting dose is one tablet in the morning for the first week, gradually increasing to the full dose over four weeks.

Side effects: Contrave may cause upset stomach, constipation, headache, dizziness, trouble sleeping, and dry mouth. Some people may have diarrhea. It can raise blood pressure and heart rate, which may be bad for people with heart problems. Rarely, it may cause seizures, especially in people who had seizures before or have eating disorders. It can also cause a serious eye problem called angle-closure glaucoma. Some people may be allergic to Contrave and get a rash, itching, or trouble breathing. Not everyone will have these side effects, and they can be different for each person. It’s important to talk to a doctor to understand the risks and benefits of taking Contrave.

Comparison Chart of the Top 8 Prescription Weight Loss Drugs

Drug Name	Ingredients	Mechanism of Action	Dosage	Common Side Effects
Wegovy	Semaglutide	GLP-1 receptor agonist; reduces appetite	Once-weekly injection; starting dose 0.25 mg, up to 2.4 mg	Nausea, diarrhea, vomiting, constipation, abdominal pain
Saxenda/Victoza	Liraglutide	GLP-1 receptor agonist; reduces appetite	Once-daily injection; 0.6 mg to 3.0 mg (Saxenda), 0.6 mg to 1.8 mg (Victoza)	Nausea, diarrhea, constipation, vomiting, low blood sugar
Invokana/Farxiga	Canagliflozin (Invokana), Dapagliflozin (Farxiga)	SGLT2 inhibitors; increase glucose excretion	Once-daily oral; 100-300 mg (Invokana), 5-10 mg (Farxiga)	Genital yeast infections, urinary tract infections, increased urination
Naltrexone (with bupropion)	Naltrexone hydrochloride	Opioid antagonist; reduces cravings and appetite	Two tablets twice daily (8 mg naltrexone, 90 mg bupropion per tablet)	Nausea, headache, dizziness, insomnia, vomiting
Metformin	Metformin hydrochloride	Decreases glucose production and absorption, improves insulin sensitivity	500-2000 mg per day, taken 2-3 times daily with meals	Diarrhea, nausea, vomiting, bloating, gas, stomach pain
Phentermine	Phentermine hydrochloride	Appetite suppressant; stimulates neurotransmitter release	18.75-56.25 mg once daily, usually 37.5 mg	Dry mouth, constipation, insomnia, dizziness, irritability
Qsymia (phentermine/topiramate)	Phentermine hydrochloride, topiramate extended-release	Appetite suppressant and anticonvulsant; increases feelings of fullness	3.75 mg/23 mg to 15 mg/92 mg once daily	Dry mouth, constipation, insomnia, dizziness, taste alterations
Contrave (bupropion/naltrexone)	Bupropion hydrochloride, naltrexone hydrochloride	Antidepressant and opioid antagonist; reduces appetite and cravings	Two tablets twice daily (8 mg naltrexone, 90 mg bupropion per tablet)	Nausea, constipation, headache, vomiting, dizziness, insomnia

What are the Most Effective Weight Loss Medications in the Market?

The effectiveness of weight loss medications can vary from person to person, and the best medication for an individual depends on their unique circumstances, health status, and response to treatment. However, among the medications discussed, Wegovy (semaglutide) and Saxenda (liraglutide) have shown significant promise in clinical trials and are considered some of the strongest weight loss drugs in 2024.

In a clinical trial, participants taking Wegovy lost an average of 14.9% of their initial body weight over 68 weeks, compared to 2.4% for those taking a placebo. Similarly, participants taking Saxenda lost an average of 8.4% of their initial body weight over 56 weeks, compared to 2.8% for those taking a placebo.

It is essential to note that while these medications can be effective for weight loss, they should be used in conjunction with a comprehensive lifestyle modification program that includes a balanced diet, regular physical activity, and behavioral changes. Additionally, the long-term effectiveness and safety of these medications are still being studied, and individual results may vary.

How weight loss medications work

Weight-loss drugs work through various mechanisms to help individuals lose weight. The three main mechanisms are:

1. Appetite suppression: Some weight loss medications work by reducing appetite, making individuals feel full faster and for longer periods. This can lead to a decrease in calorie intake and ultimately weight loss. Medications like phentermine, Qsymia, and Contrave work primarily through this mechanism.
2. Fat absorption inhibition: Certain medications, such as orlistat (Xenical), work by inhibiting the absorption of dietary fat in the intestines. By reducing the amount of fat absorbed from food, these medications can help reduce calorie intake and promote weight loss.
3. Metabolic rate enhancement: Some medications, such as phentermine and Qsymia, may also increase the body’s metabolic rate, helping individuals burn more calories at rest. This can contribute to weight loss when combined with a reduced-calorie diet and increased physical activity.

It is important to note that while these mechanisms can help with weight loss, they are not a substitute for a healthy lifestyle. Weight loss medications should be used in combination with a balanced diet, regular physical activity, and behavioral modifications for optimal results.

The role of prescription medicine in obesity treatment

Prescription drugs play an important role in the comprehensive treatment of obesity. They are typically prescribed to individuals with a BMI of 30 or higher or those with a BMI of 27 or higher who also have weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnea.

The primary goals of using weight loss medications are to:

1. Help patients achieve and maintain a healthy weight
2. Reduce the risk of obesity-related health complications
3. Improve overall health and quality of life

When used in combination with lifestyle modifications, such as a balanced diet, regular physical activity, and behavioral changes, prescription drugs can help patients achieve significant weight loss and improve their health outcomes.

However, it is crucial to understand that these medications are not a quick fix or a long-term solution for obesity. They should be used under the guidance of a healthcare professional and as part of a comprehensive weight management program. Patients should also be aware of the potential side effects and risks associated with these medications and work closely with their healthcare provider to monitor their progress and adjust treatment as needed.

Risks and side effects of weight loss medications

Prescription weight-loss drugs offer a promising approach to treating obesity, but they are not without their drawbacks, including potential risks and side effects. Among the most commonly reported side effects are:

1. Gastrointestinal issues: Nausea, vomiting, diarrhea, constipation, and stomach pain are common side effects of many weight loss medications.
2. Headache and dizziness: Some patients may experience headaches or dizziness when taking weight loss drugs.
3. Insomnia: Certain medications, such as phentermine and Qsymia, may cause difficulty sleeping or insomnia.
4. Dry mouth: Many weight loss medications can cause dry mouth as a side effect.
5. Increased heart rate and blood pressure: Some medications, particularly stimulants like phentermine, can increase heart rate and blood pressure.

More serious, but rare, side effects may include:

1. Liver damage: Naltrexone, when used in combination with bupropion (Contrave), has been associated with a risk of liver damage.
2. Kidney problems: SGLT2 inhibitors, such as Invokana and Farxiga, may increase the risk of kidney problems.
3. Suicidal thoughts: Some medications, like bupropion (Contrave), have been linked to an increased risk of suicidal thoughts or behaviors.
4. Birth defects: Qsymia (phentermine/topiramate) can cause birth defects if taken during pregnancy.

Patients should discuss the potential risks and side effects with their healthcare provider before starting any weight loss medications. Regular monitoring and follow-up appointments are essential to ensure the safe and effective use of these drugs.

Who should consider prescription weight loss medications

Weight loss drugs are not intended for everyone who wants to lose weight. They are typically reserved for individuals who meet specific criteria, such as:

1. Those with a BMI of 30 or higher, which is considered obese.
2. Those with a BMI of 27 or higher also have weight-related health conditions, such as type 2 diabetes, high blood pressure, or sleep apnea.
3. Those who have struggled to lose weight through lifestyle modifications alone, such as diet and exercise.
4. Those who are committed to making long-term lifestyle changes to support weight loss and maintain a healthy weight.

Before prescribing weight loss medications, healthcare providers will evaluate a patient’s medical history, current health status, and potential contraindications. They will also discuss the expected benefits, potential risks, and side effects of the medications to help patients make an informed decision.

Criteria for prescribing weight loss medications

Healthcare providers generally follow specific criteria when prescribing weight loss medications to ensure that the benefits outweigh the potential risks. These criteria include:

1. BMI requirements

– Individuals with a BMI of 30 or higher, which is considered obese, may be prescribed weight loss medications

– Those with a BMI of 27 or higher who also have weight-related health conditions, such as type 2 diabetes, high blood pressure, or sleep apnea, may also be candidates for these medications.

2. Presence of weight-related health conditions

– Patients with obesity-related health conditions, such as type 2 diabetes, high blood pressure, high cholesterol, or sleep apnea, may benefit from weight loss medications in addition to lifestyle modifications.

– These medications can help improve health outcomes and reduce the risk of complications associated with these conditions.

Before prescribing weight loss drugs, healthcare providers will assess a patient’s overall health, medical history, and any potential contraindications. They will also discuss the expected benefits, potential risks, and side effects of the medications to ensure that patients can make an informed decision about their treatment options.

What is Injectable Prescription Weight Loss Medicine?

Injectable  prescription drugs are medications that are administered through subcutaneous injections, typically in the abdomen, thigh, or upper arm. These medications are usually prescribed for individuals with a BMI of 30 or higher or those with a BMI of 27 or higher who also have weight-related health conditions.

The most common injectable prescription drugs for weight loss are:

1. Wegovy (semaglutide): Wegovy is a once-weekly injectable medication that helps with weight loss by reducing appetite and increasing feelings of fullness. It is a glucagon-like peptide-1 (GLP-1) receptor agonist that mimics the effects of the hormone GLP-1, which regulates appetite and food intake.
2. Saxenda (liraglutide): Saxenda is a once-daily injectable medication that contains liraglutide, another GLP-1 receptor agonist. It works similarly to Wegovy by reducing appetite and increasing feelings of fullness, helping patients to lose weight.

Injectable prescription weight loss drugs have shown significant promise in clinical trials, with participants losing a substantial percentage of their initial body weight when compared to placebo. However, like oral weight loss medications, they should be used in conjunction with a comprehensive lifestyle modification program that includes a balanced diet, regular physical activity, and behavioral changes.

When Should You Ask Your Doctor To Prescribe Weight Loss Drugs?

If you have been struggling to lose weight through lifestyle modifications alone, such as diet and exercise, and meet the criteria for prescription medicines, it may be appropriate to discuss this option with your healthcare provider. You should consider asking your doctor about weight loss medications if:

1. You have a BMI of 30 or higher, which is considered obese.
2. You have a BMI of 27 or higher and also have weight-related health conditions, such as type 2 diabetes, high blood pressure, or sleep apnea.
3. You have tried to lose weight through lifestyle changes but have not been successful.
4. You are committed to making long-term lifestyle changes to support weight loss and maintain a healthy weight.

When discussing weight loss medications with your doctor, be prepared to talk about your medical history, current health status, and any medications you are currently taking. Your doctor will also likely discuss the potential benefits, risks, and side effects of the various weight loss medications to help you make an informed decision.

Remember that prescription drugs are not a magic solution for obesity. They should be used as part of a comprehensive weight management program that includes a balanced diet, regular physical activity, and behavioral modifications. Your doctor can help you develop a personalized plan that incorporates these elements to support your weight loss journey.

How Fat Burning Medications Work?

Fat burning medication drugs, also known as lipase inhibitors, work by inhibiting the absorption of dietary fat in the intestines. The most common fat burning medication is orlistat, which is available by prescription as Xenical and over-the-counter as Alli.

Here’s how Orlistat works:

1. Inhibiting fat absorption: Orlistat inhibits the action of lipase, an enzyme that breaks down dietary fat in the intestines. By blocking this enzyme, orlistat reduces the amount of fat that is absorbed from food and passes through the digestive system undigested.
2. Reducing calorie intake: By reducing the amount of fat absorbed from food, orlistat can help decrease overall calorie intake. This can lead to weight loss when combined with a reduced-calorie diet and regular physical activity.
3. Encouraging healthy eating habits: When taking orlistat, patients may experience gastrointestinal side effects if they consume a high-fat meal. This can encourage individuals to adopt healthier eating habits and make more balanced food choices.

It is important to note that while fat-burning medications like Orlistat can help with weight loss, they are not a substitute for a healthy lifestyle. These medications should be used in combination with a balanced diet, regular physical activity, and behavioral modifications for optimal results. Additionally, patients should be aware of the potential side effects, such as oily stools, flatulence, and urgent bowel movements, and discuss these with their healthcare provider before starting treatment.

Do prescription medications really help you lose weight?

Prescription medications can be effective in helping individuals lose weight when used in conjunction with a comprehensive weight management program that includes a balanced diet, regular physical activity, and behavioral modifications. Clinical trials have shown that participants taking these medications can lose a significant percentage of their initial body weight compared to those taking a placebo.

For example:

1. Wegovy (semaglutide): In a clinical trial, participants taking Wegovy lost an average of 14.9% of their initial body weight over 68 weeks, compared to 2.4% for those taking a placebo.
2. Saxenda (liraglutide): Participants taking Saxenda lost an average of 8.4% of their initial body weight over 56 weeks, compared to 2.8% for those taking a placebo.
3. Qsymia (phentermine/topiramate): In clinical trials, participants taking Qsymia lost an average of 8.1% to 10.9% of their initial body weight, depending on the dose, compared to 1.8% for those taking a placebo.

While these results are promising, it is essential to remember that individual results may vary, and the long-term effectiveness and safety of these medications are still being studied. Additionally, weight loss medications are not a magic solution for obesity and should not be relied upon as the sole method for weight loss.

To achieve sustainable weight loss and improve overall health, patients should work closely with their healthcare provider to develop a comprehensive weight management plan that includes:

1. A balanced, reduced-calorie diet
2. Regular physical activity
3. Behavioral modifications and support
4. Ongoing monitoring and adjustments to treatment as needed

By combining prescription medications with a holistic approach to weight management, individuals can improve their chances of achieving and maintaining a healthy weight, reducing the risk of obesity-related health complications, and enhancing their overall quality of life.

To summarize, prescription weight-loss drugs can be a valuable asset for individuals striving to lose weight when they are used as part of a complete weight management plan and under the guidance of a doctor. Although these medications can help people lose weight, they should not be considered the only approach. Patients should always talk to their doctor about the possible benefits, risks, and side effects, and commit to making permanent lifestyle changes to support their weight loss efforts.