Tirzepatide for
Medical Weight Loss

What Is Tirzepatide?

Tirzepatide is a first-in-class dual GLP-1 and GIP receptor agonist that has rapidly become the most discussed and sought-after treatment in medical weight loss. Originally developed by Eli Lilly, it is marketed as Mounjaro for type 2 diabetes and Zepbound for chronic weight management. Tirzepatide received FDA approval for weight loss in November 2023, following landmark clinical trial results.

Unlike previous weight loss medications that target a single hormonal pathway, tirzepatide works on two incretin hormones simultaneously: GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide). This dual mechanism of action is what makes tirzepatide significantly more effective than single-pathway treatments.

How Does Tirzepatide Work?

To understand tirzepatide, it helps to understand the incretin hormones it mimics. When you eat, your gut releases GLP-1 and GIP, two hormones that play important roles in metabolism:

• GLP-1 (Glucagon-Like Peptide-1) signals the brain to reduce hunger, slows the rate at which food leaves the stomach (gastric emptying), and stimulates insulin release from the pancreas. This leads to reduced appetite, earlier fullness after meals, and improved blood sugar control.
• GIP (Glucose-Dependent Insulinotropic Polypeptide) enhances insulin secretion, promotes fat metabolism, and works synergistically with GLP-1 to amplify appetite suppression and metabolic improvements.

Tirzepatide is a synthetic molecule that activates both the GLP-1 and GIP receptors with high affinity. By targeting both pathways, it produces more pronounced effects on appetite, metabolism, and body composition than GLP-1-only medications like semaglutide. The medication is administered as a once-weekly subcutaneous injection, typically in the abdomen, thigh, or upper arm.

Clinical Trial Results

Tirzepatide's efficacy has been demonstrated in multiple large-scale clinical trials. The most significant for weight loss are the SURMOUNT trial series:

SURMOUNT-1 Trial

This pivotal trial enrolled over 2,500 adults with obesity or overweight with at least one weight-related condition (excluding diabetes). Over 72 weeks of treatment:

• Participants on the highest dose (15 mg) lost an average of 22.5% of their body weight
• The 10 mg dose produced an average of 19.5% body weight loss
• The 5 mg dose produced an average of 15% body weight loss
• Over one-third of participants on the highest dose lost 25% or more of their body weight

Benefits of Tirzepatide Treatment

The benefits of tirzepatide extend well beyond the number on the scale. Patients at our Knoxville clinic commonly experience:

Who Is a Candidate for Tirzepatide?

At Weight Loss Knox, our physicians evaluate each patient individually to determine whether tirzepatide is appropriate. Generally, candidates for tirzepatide include adults who meet the following criteria:

• BMI of 30 or greater (obesity), or
• BMI of 27 or greater (overweight) with at least one weight-related health condition such as type 2 diabetes, high blood pressure, high cholesterol, or obstructive sleep apnea
• Previous unsuccessful attempts at weight loss through diet and exercise alone
• No contraindications to GLP-1/GIP therapy

Treatment Process at Weight Loss Knox

Tirzepatide vs. Semaglutide

Frequently Asked Questions