By Naomi Carr

Updated: 05 April 2024 & medically reviewed by Morgan Blair

With around one-third of American adults being overweight [1] and the increase of influencer culture on social media, the demand for fast and easy weight loss is ever-increasing. Several medications are being used to lose weight quickly and are becoming increasingly popular across the US.

Weight Loss Drugs: Understanding America's Latest Drug Obsession

What are weight loss drugs?

Weight loss drugs are medications that can be used to suppress appetite and promote weight loss. Many of these medications were actually designed to treat type 2 diabetes, to help regulate blood sugar levels. However, in recent years, the Food and Drug Administration (FDA) has approved some of these medications for weight loss purposes. [2]

Zepbound and Mounjaro (tirzepatide)

Tirzepatide is the substance found in the medications Zepbound and Mounjaro. Zepbound was approved for weight management in November 2023. Mounjaro is FDA-approved to manage blood sugar levels for people with diabetes but is not approved for weight loss. [3][4]

Tirzepatide works by activating two receptors at the same time: the glucagon-like peptide-1 (GLP-1) receptor and the glucose-dependent insulinotropic polypeptide (GIP) receptor. This dual action is believed to contribute to its increased effectiveness in reducing body weight compared to other weight loss medications. [5][6]

Tirzepatide helps weight loss by stimulating insulin secretion. This slows the time it takes for the stomach to empty, causing individuals to feel full after consuming less food and for a longer time. This helps reduce snacking and meal sizes, causing a significant reduction in calorie consumption. Studies have shown that this medication can contribute to a 15-25% decrease in body weight. [6]

Zepbound and Mounjaro are available as single-use injection pens, in 2.5mg, 5mg, 6.5mg, 10mg, 12.5mg, and 15mg strengths, which should be administered once per week. A usual starting dose of Zepbound for weight loss is 2.5mg per week, which can be gradually increased to 15mg. [3][4]

Wegovy and Ozempic (semaglutide)

Semaglutide is the substance found in the medications Wegovy and Ozempic. Ozempic is arguably the most well-known weight loss drug in the media at present, although it is not FDA-approved for this purpose and is often prescribed off-label. Wegovy has been approved for weight management since June 2021. [7][8]

Semaglutide is a GLP-1 receptor agonist. It has been found to contribute to a 10-15% reduction in body weight and should be administered in a once-weekly injection. [9] 

Wegovy is available as a single-use injection pen in 0.25mg, 0.5mg, 1mg, 1.7mg, and 2.4mg strengths. Ozempic is available as a single-use injection pen in 0.25mg, 0.5mg, and 1mg strengths. Wegovy is typically prescribed with a starting dose of 0.25mg per week, which can be gradually increased to 2.4mg per week. [7][8]

People taking Ozempic have reported shaking long-established addictions to nicotine, alcohol, caffeine, and illicit drugs. Ozempic also seems to curb behavioral addictions such as binge eating, shopping, overspending, and even compulsive habits like nail-biting. Users have reported relief from general obsessive thoughts as well.

Saxenda (liraglutide)

Saxenda contains the substance liraglutide, which is also a GLP-1 receptor agonist, similar to Wegovy and Ozempic. Saxenda was approved for weight management in December 2014 and has been shown to contribute to approximately 5% reduction in body weight. [2]

Saxenda is available as a single-use injection pen in 0.6mg, 1.2mg, 1.8mg, 2.4mg, and 3mg strengths. A typical starting dose is 0.6mg per day, which can be gradually increased to a maximum of 3mg per day. [10]

Contrave (bupropion and naltrexone)

Contrave contains bupropion, an aminoketone antidepressant, and naltrexone, an opioid antagonist. It was approved for weight loss purposes in September 2014. It has been found to contribute to a 5-10% reduction in body weight, through increased metabolism, suppressed appetite, and an impact on the brain’s reward center. [2][11]

Contrave is available as an extended-release tablet, containing 8mg of naltrexone and 90mg of bupropion. A typical starting dose is one tablet per day, which can be gradually increased to four tablets per day. [11]

Because of the substances contained in Contrave, it carries additional risks and side effects to the previously mentioned weight loss drugs. This can include a risk of seizures, suicidal ideation, abuse, and dependence. [11]

Qsymia (phentermine and topiramate)

Qsymia contains phentermine, a sympathomimetic amine anorectic, and topiramate, an anticonvulsant. It was approved for weight loss purposes in July 2012 and can contribute to a 5-10% reduction in body weight, through suppressed appetite. [2][12]

Qsymia is available as an extended-release capsule containing 3.75mg/23mg, 7.5mg/46mg, 11.25mg/69mg, and 15mg/92mg (phentermine/topiramate). A typical starting dose is 3.75mg/23mg once per day, which can be gradually increased to a maximum of 15mg/92mg per day. It should be taken in the morning to prevent insomnia. [12]

Many celebrities and influencers have shared their rapid weight loss with the use of medications such as Ozempic and Wegovy, including Elon Musk and Oprah Winfrey. [13][14]

While these celebrities have shared the benefits and positive results of these medications, many have not shared their experience of side effects or the additional dietary and physical changes made alongside the medication. This has contributed to the widely held view that these medications are consistently safe, effective, and fast-acting. 

Professionals recommend making changes to diet, exercise, and lifestyle alongside their use, to have the most successful outcomes, while being closely monitored throughout treatment. [2][13]

Unfortunately, due to the rise in popularity of these drugs for weight loss, there are reports of shortages occurring. Many people with diabetes who require these medications for life-saving treatment are unable to obtain them. [13]

Are there any side effects to weight loss drugs?

It is not unusual to experience side effects when beginning a new medication or increasing the dosage. These weight loss medications often cause temporary side effects when treatment commences, which typically reduce within several weeks or months of use. 

However, for some people, these side effects are not alleviated with time and can cause persistent or severe issues that require professional treatment or the stopping of the medication. It is recommended for individuals using these medications to be closely monitored by a professional throughout treatment, to ensure their safety. [2][13]

Common side effects of weight loss medications include: [3][7][10]

In rare cases, severe side effects can occur, which include: [3][7][10]

  • Pancreatitis

  • Gallbladder disease

  • Thyroid cancer

  • Kidney failure

  • Severe gastrointestinal disease

  • Hypoglycemia

  • Suicidal thoughts and behaviors

The long-term side effects of these medications are not currently known, although it is thought that there are no severe long-term effects. [6]

What happens if you stop taking weight loss drugs?

Studies show that weight loss drugs can consistently maintain weight loss as long as the medication is continued. If the medication is stopped, appetite often increases, and any weight lost during treatment is likely to be regained. [6][9]

Stopping these medications can cause changes in metabolism and blood sugar levels, which can also contribute to changes in weight.

Gastrointestinal effects such as nausea and diarrhea that are caused by the medication will stop once the medication is stopped.

Some of these medications can cause certain withdrawal symptoms or increased health risks if stopped abruptly, so it can be necessary to gradually taper off the medication to prevent these risks. [11][12]

Are weight loss drugs available to everyone?

Weight loss drugs are only available on prescription, following an assessment by a medical professional. FDA guidelines state that they should only be prescribed to people with a BMI (body mass index) over 30kg/m², or a BMI over 27kg/m²with a weight-related medical condition. [3][7][10]

These treatments should only be prescribed as a second-line treatment for weight loss, following attempts to lose weight with diet and exercise. Changes to diet and exercise should also continue to be implemented alongside the use of these medications, for the most effective results. [2]

Some insurance companies will cover weight loss medications if they are deemed medically necessary and are covered by the individual’s plan. Without insurance, these medications can be very expensive. [13]