What are the Best Prescription Weight Loss Medications?

October 16, 2024

2 mins

When lifestyle changes like diet and exercise aren’t enough to achieve significant weight loss, prescription medications may offer additional support. For those with obesity or weight-related health issues, prescription weight loss medications can be a game-changer. These medications target different aspects of weight regulation – such as appetite control, fat absorption, and metabolic rate – that may help patients manage their weight more effectively. 

In this article, we’ll explore some of the most effective prescription weight loss medications, how they work, and how they can be part of a comprehensive weight management plan under medical supervision.

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Appetite Suppressants

Appetite suppressants are medications designed to reduce hunger and help control food intake. They can make it easier to follow a calorie-restricted diet. They work by influencing the brain’s hunger signals, often targeting the areas that regulate feelings of fullness and appetite. 

Prescription appetite suppressants – such as phentermine or GLP-1 receptor agonists like semaglutide and liraglutide – can decrease cravings and help promote the feeling of fullness sooner. These medications are typically prescribed for those with obesity or weight-related health issues and are intended to be used alongside a healthy diet and exercise program for the best results.

Phentermine 

Phentermine is a stimulant that helps suppress appetite by acting on the central nervous system. It works by releasing neurotransmitters like norepinephrine, which tell the brain to reduce hunger signals, making it easier to eat less.

Because it’s a stimulant, phentermine is usually prescribed for short-term use – typically just a few weeks to a few months – as part of a broader weight loss plan that includes healthy eating and exercise.

Since it can cause side effects like an increased heart rate or elevated blood pressure, doctors closely monitor its use. For those needing longer-term weight management, phentermine is often paired with other medications to maintain its appetite-suppressing benefits while reducing the risks that come with extended stimulant use. It's also classified as a Schedule IV controlled substance because of its potential for abuse, so it’s prescribed with caution.

Phentermine is available in several forms, typically as oral tablets or capsules. It can be found in:

• Immediate-release tablets: Taken once daily, usually before breakfast or within a few hours of waking up.

• Extended-release capsules: These are designed to release the medication gradually throughout the day to provide longer-lasting appetite suppression.

• Orally disintegrating tablets (ODT): These dissolve on the tongue without the need for water, offering a convenient option for those who may have difficulty swallowing pills.

Each form is prescribed based on individual patient needs and the doctor’s recommendations.

GLP-1 medications 

GLP-1s (glucagon-like peptide-1 receptor agonists) are a class of medications that mimic a natural hormone in the body responsible for regulating blood sugar and appetite. They help reduce hunger, increase feelings of fullness, and slow down digestion, making it easier to eat less. 

Originally developed for treating type 2 diabetes, GLP-1s like semaglutide, tirzepatide, and liraglutide are now commonly prescribed for weight loss in people with obesity. They work best when combined with a healthy diet and exercise.

Semaglutide

Semaglutide is a GLP-1 receptor agonist prescribed to promote weight loss. It works by reducing appetite, increasing feelings of fullness, and regulating blood sugar levels. Available under brand name Wegovy®, the semaglutide injection is often prescribed to people with obesity or weight-related conditions to support long-term weight management when combined with diet and exercise.

Tirzepatide

Tirzepatide is an injection medication similar to semaglutide. It acts on both GLP-1 and GIP receptors, making it effective for aiding in weight loss. It helps lower blood sugar levels, reduces appetite, and enhances feelings of fullness. Marketed for weight loss as Zepbound®, tirzepatide has demonstrated impressive results in supporting sustainable weight loss when paired with a healthy diet and exercise.

Liraglutide

Liraglutide is a GLP-1 receptor agonist used to treat type 2 diabetes and help with weight management. It works by increasing insulin secretion, reducing appetite, and slowing gastric emptying, which helps promote feelings of fullness. Available under brand names like Saxenda® for weight loss, liraglutide is often prescribed to support individuals in achieving and maintaining a healthier weight alongside lifestyle changes.

Fat Absorption Inhibitors

Fat absorption inhibitors are prescription medications designed to prevent the body from absorbing some of the fat from the food you eat – which can help with weight loss. The primary prescription fat absorption inhibitor is orlistat (Xenical).

Orlistat works by blocking the enzyme lipase, which breaks down dietary fat in the intestines. When this enzyme is inhibited, about 25-30% of the fat consumed is not absorbed and is instead excreted through the stool. This can help reduce overall calorie intake and promote weight loss.

Orlistat is also available in a lower dose over-the-counter as Alli. However, it's important to note that while this medication can help with weight loss, it must be combined with a low-fat diet to minimize side effects, such as oily stools, flatulence, and frequent bowel movements.

Because orlistat reduces the absorption of fat, it can also impact the absorption of fat-soluble vitamins (A, D, E, and K), so a multivitamin supplement may be recommended when using this medication.

As with other prescription medications for weight loss, it's best to consult a healthcare provider to determine if fat absorption inhibitors are appropriate based on your health needs.

Combination Therapies

Prescription combination therapies for weight loss involve using two or more medications to target different mechanisms involved in hunger, metabolism, and fat storage. These combinations can enhance the effectiveness of weight loss treatments while sometimes reducing the intensity of side effects that might occur if higher doses of a single medication were used. Here are some commonly prescribed combination therapies:

Phentermine-topiramate (Qsymia)

• Phentermine: A stimulant that suppresses appetite by affecting the central nervous system.

• Topiramate: An anticonvulsant medication that can promote feelings of fullness, reduce cravings, and impact food preference.

This combination helps reduce appetite and increase the sensation of fullness, making it easier to stick to a calorie deficit. Qsymia is typically prescribed for long-term use in individuals with obesity or weight-related health problems.

Naltrexone-bupropion (Contrave)

• Naltrexone: Commonly used to treat addiction by blocking the effects of opioids and reducing cravings.

• Bupropion: An antidepressant and smoking cessation aid that also has appetite-suppressing effects.

Together, these medications target the brain's hunger and reward pathways, helping to reduce food cravings and control emotional eating. Contrave is often prescribed for patients who have struggled with long-term weight management.

Metformin and GLP-1 agonists (off-label combination)

Metformin is primarily used for diabetes management, metformin can also have weight-loss effects by improving insulin sensitivity and reducing appetite.

When combined with GLP-1 receptor agonists like liraglutide or semaglutide, this combination may enhance weight loss by managing both blood sugar and hunger levels.

Phentermine and other GLP-1 (off-label combinations)

Although not a formal combination therapy, some doctors may prescribe phentermine alongside semaglutide or liraglutide to capitalize on their complementary appetite-suppressing effects. These combinations require close medical supervision due to the risks of increased side effects, such as elevated blood pressure.

Combination therapies are often prescribed for patients who have not responded well to single-drug treatments or for those with complex weight-loss needs. Like any weight-loss intervention, these therapies are most effective when combined with lifestyle modifications such as healthier eating and increased physical activity. As with all prescription medications, it's essential to consult a healthcare provider to assess the risks and benefits based on individual health conditions.

How Rex MD Can Help

If you’re interested in learning more about the best prescription weight loss medications, Rex MD can help. With the Rex MD Weight Management Program, you’ll gain access to compounded semaglutide medications along with clinical oversight, metabolic testing, and ongoing support from licensed healthcare providers, if you qualify. 

There’s no commitment to get started. See if you qualify to lose weight with Rex MD.