What is Semaglutide? How GLP-1 Medications Help You Lose Weight

Semaglutide has become one of the most talked-about weight loss medications in years — and for good reason. Clinical trials show patients losing 15–20% of their body weight. But what exactly is semaglutide, how does it work, and is it right for you?

What is Semaglutide?

Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist. GLP-1 is a hormone your body naturally produces after eating — it signals your brain that you're full and helps regulate blood sugar. Semaglutide mimics this hormone, keeping those signals active for much longer than your body naturally would.

Originally developed to treat type 2 diabetes (sold as Ozempic), semaglutide was approved by the FDA for chronic weight management under the brand name Wegovy in 2021. Compounded semaglutide is now widely available through telehealth providers at a fraction of the brand-name cost.

How Does Semaglutide Cause Weight Loss?

Semaglutide works through several mechanisms simultaneously:

• Reduces appetite: By activating GLP-1 receptors in the brain, semaglutide significantly reduces hunger and food cravings.
• Slows gastric emptying: Food moves more slowly from your stomach to your small intestine, keeping you feeling full longer.
• Improves insulin sensitivity: Helps your body use insulin more effectively, reducing fat storage.
• Reduces reward-driven eating: Studies show semaglutide reduces the dopamine response to food, making it easier to resist cravings.

What Results Can You Expect?

Results vary by individual, but clinical data shows:

• Most patients see noticeable appetite reduction within the first 1-2 weeks
• Average weight loss of 5-10% in the first 3 months
• Average total weight loss of 15-20% over 12-18 months with consistent use
• Improved blood sugar, blood pressure, and cholesterol in many patients

Semaglutide vs. Tirzepatide

Tirzepatide (the active ingredient in Mounjaro and Zepbound) is a newer GLP-1 medication that also targets the GIP receptor. Head-to-head trials show tirzepatide produces slightly greater weight loss — around 22% on average — making it the most effective option currently available. However, semaglutide has a longer track record and is often the preferred starting point.

How is Semaglutide Taken?

Semaglutide is available as a once-weekly subcutaneous injection. Compounded oral semaglutide (daily tablet) is also available through some telehealth providers like Zera Health, making it accessible for patients who prefer not to inject.

Dosing typically starts low and is gradually increased over several months to minimize side effects and find your optimal dose.

Common Side Effects

The most common side effects are gastrointestinal and usually temporary:

• Nausea (most common, especially at the start)
• Constipation or diarrhea
• Reduced appetite (this is also the intended effect)
• Mild fatigue

Starting at a low dose and increasing gradually significantly reduces the likelihood of side effects. Most patients find them manageable and they tend to improve within 4-8 weeks.

Who is a Good Candidate for Semaglutide?

Semaglutide is clinically appropriate for adults who:

• Have a BMI of 30 or higher (obese), OR
• Have a BMI of 27 or higher with at least one weight-related condition (high blood pressure, type 2 diabetes, high cholesterol)
• Have not achieved adequate weight loss through diet and exercise alone

It is not appropriate for individuals with a personal or family history of medullary thyroid carcinoma, multiple endocrine neoplasia syndrome type 2, or severe gastrointestinal disease. A licensed provider will evaluate your complete health history during consultation.