In June 2021, the FDA approved Semaglutide (Wegovy), a once-weekly injection, for chronic weight management when used in combination with a healthy diet and exercise. The medication had made headlines before its approval when the manufacturer reported 15% to 18% weight loss findings during clinical trials. This is higher than we tend to see with other weight loss medications.

So, is semaglutide right for you? While it may work better than some other weight loss medications.

What is semaglutide?

Semaglutide is an injectable glucagon-like peptide-1 (GLP-1) agonist that's administered once weekly. It was originally approved in 2017- at a lower dose under the brand name Czempic- to help control blood sugar in Type 2 diabetes. People taking Ozempic for blood sugar control also tend to lose weight as an additional benefit.

Because of this, Novo Nordisk studied the medication in people without Type 2 diabetes, but at a higher dose. Now, semaglutide (under the brand name Wegovy) is FDA-approved for weight loss. It can be used by adults with a body mass index (BMI) greater than or equal to 30 mg/kg alone or 27 mg/kg2 with at least one weight-related condition (e.g., high blood pressure, high cholesterol, Type 2 diabetes).

Semaglutide should be used in combination with lifestyle changes, including a healthy diet and exercise.

How does semaglutide work for weight loss?

GLP-1 is an incretin hormone that plays a role in your appetite and digestion. Incretins- hormones released by your digestive tractare sent out by your body after you've eaten a meal. They help lower your blood sugar by triggering insulin release and blocking sugar production. They also slow down how quickly food leaves your stomach (called gastric emptying).

The result of these actions causes you to feel full-lowering your appetite and causing you to lose weight. Medications like GLP-1 agonists are referred to as incretin mimetics since they "mimic" these effects.

As mentioned above, GLP-1 agonists, like semaglutide, were originally used to treat Type 2 diabetes. This was due to their blood sugar-lowering effects. However, the weight loss side effect has been shown to benefit people without Type 2 diabetes as well.

How is semaglutide dosed?

Semaglutide is available as a single-use injection pen. This means that your dose is already pre-set for you, and that you'll discard the pen after your dose.

You'll give yourself the injection once a week, on the same day each week. It can be given at any time of day, and you can take it with or without food.

Semaglutide is typically injected just under the skin (subcutaneously) in your abdomen, upper arm, or thigh. Avoid injecting the medication into the same spot every time-change your injection site with each dose. But injecting in the same body area (e g., thigh) is OK as long as you're rotating sites within the area each time.

Since semaglutide slows down how quickly food leaves your stomach, you may experience side effects like nausea and vomiting. Once you get started on the medication, your healthcare provider will slowly increase your dosage every 4 weeks. This can help make these effects more manageable.

The target dose is 2.4 mg once weekly. Before reaching the target dose, a typical dosing schedule may look like:

  • Month 1: 0.25 mg once weekly for the first menth
  • Month 2: 0.5 mg once weekly for the second month
  • Month 3: 1 mg once weekly for the third month
  • Month 4: 15 mg once weekly for the fourth month
  • Target maintenance dose: 2.5 mg once weekly

Some people may not be able to reach or tolerate the target dose due to side effects. If this is the case, your healthcare provider may wait another month before increasing your dose. However, they may have you stop the medication if you're unable to reach or stay on the target dose.

What do we know about semaglutide side effects?

As introduced earlier, gastrointestinal (GI) side effects tend to happen most frequently when taking this medication. The most common are nausea, diarrhea, and vomiting. You may experience these effects more strongly when your healthcare provider increases your dose.

Additional common side effects can include:

  • Constipation
  • Stomach pain
  • Headache
  • Fatigue
  • Indigestion
  • Dizziness
  • Bloating
  • Burping

Serious side effects

In some cases, semaglutide may cause more serious side effects: The medication has a boxed warning the FDA's most serious warning - for a potential risk for thyroid C-cell tumars. This risk has been seen in animal studies, but it hasn't been confirmed in people. Because of this, you shouldn't take semaglutide if you have a personal or family history of certain thyroid tumors.

Other serious side effects can include:

  • Pancreatitis (inflamed pancreas)
  • Cholelithiasis (gallbladder disease)
  • Kidney damage
  • Low blood sugar (hypoglycemia)
  • Allergic reactions (including swelling of the face, tongue, or throat, difficulty breathing)
  • Certain eye problems in people with Type 2 diabetes
  • Fast heart rate

Suicidal thoughts and behaviors are another risk listed on the medication's labeling because it's been reported with other weight loss medications. Let your healthcare provider know right away if you're experiencing any changes in mood or behavior, or if you're having suicidal thoughts.

Can semaglutide interact with other medications?

Since semaglutide can lower your blood sugar, it can interact with other blood sugar- lowering medications. Examples include insulin and medications that cause insulin to be released, like sulfonylureas. Combining these medications can result in dangerously low blood sugar levels.

If you're taking one of these medications, your healthcare provider may lower the other medication's dose while starting you on semaglutide. And as a general rule, it's important to diligently monitor your blood sugar if you have Type 2 diabetes. This is especially the case before and during treatment to ensure that your readings stay within a safe range.

Another potential interaction is with oral medications. Semaglutide slows down how quickly food leaves your stomach. This may affect how certain oral medications are absorbed by your body when they're taken together. Your healthcare provider can determine which Interactions potentially affect you and how to manage them.

How does semaglutide compare to other weight loss medications?

One of the reasons there's a lot of buzz around semaglutide is the amount of weight people lost during clinical trials. Typically, we tend to see an average of 5% to 10% weight loss with other medications.

Oral weight loss medications tend to be less expensive than the injectable options, but you may not lose as much weight. Let's review a few of the more popular weight loss medications and how they compare to semaglutide.

Oral medications

Phentermine is a popular oral weight loss medication that has been around since 1959. It's approved for short-term use (a few weeks), and it's inexpensive. However, it's possible to develop a tolerance to the medication where it's no longer working for you. And it's a controlled substance.

Phentermine is also available in combination with topiramate under the brand name Qsymia. Compared to phentermine alone, Qsymia can be used for a longer period of time. Study results have shown average weight loss ranging from about 5% (at lower doses) to around 10% (at higher doses).