GLP-1 Weight Loss · Highland Park, IL
Semaglutide vs Tirzepatide: Which GLP-1 Is Right for You?
Two medications, different mechanisms, different outcomes. A physician's guide to understanding both — and why the right answer depends entirely on your biology.
Side-by-Side Comparison
How Semaglutide and Tirzepatide Compare
A clinical overview of mechanism, efficacy, and how TREVI uses both medications.
| Semaglutide | Tirzepatide | |
|---|---|---|
| Mechanism | GLP-1 receptor agonist — mimics one gut hormone that regulates insulin and appetite | Dual GLP-1 + GIP agonist ("twincretin") — activates two appetite-regulating pathways simultaneously |
| Brand Names | Ozempic® (T2D), Wegovy® (weight loss), Rybelsus® (oral) | Mounjaro® (T2D), Zepbound® (weight loss, FDA approved 2023) |
| Avg. Weight Loss | ~15% of body weight (STEP trial, 68 weeks at 2.4mg)* | ~20–22% of body weight (SURMOUNT trial, 72 weeks at 15mg)* |
| Dosing | Weekly subcutaneous injection · 0.25mg → 2.4mg | Weekly subcutaneous injection · 2.5mg → 15mg |
| At TREVI | Available Compounded with B12 | Available Compounded with B12 + B6 |
| Side Effects | Nausea, constipation, fatigue (common during dose escalation). Managed with gradual titration. | Similar GI profile to semaglutide. Some patients report better tolerability at lower doses. |
| Best For | Patients with prior GLP-1 experience or lower starting dose goals; solid evidence base across many years | Patients seeking maximum efficacy; those who haven't responded to semaglutide; higher weight loss goals |
*Clinical trial averages. Individual results vary significantly based on dose, adherence, diet, lifestyle, and health profile.
with semaglutide
with tirzepatide
by tirzepatide vs one for semaglutide
Medication Deep Dives
Understanding Each Medication
What the science says — and what Dr. Josie observes in practice.
GLP-1 Receptor Agonist
Semaglutide
Ozempic®, Wegovy®, Rybelsus® · Novo Nordisk
Semaglutide belongs to a class of medications called GLP-1 receptor agonists — a family of drugs that have been used for nearly 20 years. It works by mimicking the GLP-1 hormone your body naturally produces after eating: telling your pancreas to release insulin, slowing gastric emptying, and signaling your brain to reduce hunger and cravings.
When used for weight management, semaglutide is typically dosed weekly via subcutaneous injection. The dose escalates gradually over several months to minimize GI side effects — this is not a medication where patients start at full dose.
- FDA approved for weight management as Wegovy® (2.4mg) since 2021
- Clinical data spans 5+ years across hundreds of thousands of patients
- Single GLP-1 pathway — proven mechanism with a long safety record
- Compounded with B12 at TREVI for added nutritional support
- Sustained weight loss requires long-term use; most patients commit indefinitely
Dual GLP-1 + GIP Agonist
Tirzepatide
Mounjaro®, Zepbound® · Eli Lilly
Tirzepatide is often called a "twincretin" because it activates two separate hormone pathways: GLP-1 (the same one semaglutide targets) plus GIP (glucose-dependent insulinotropic polypeptide). The GIP hormone amplifies the GLP-1 effect on appetite — essentially sending a stronger signal to the brain to stop eating.
This dual mechanism is why clinical trials show greater average weight loss with tirzepatide compared to semaglutide. The SURMOUNT trial demonstrated an average of ~20–22% body weight reduction at the highest dose — outcomes that have reshaped expectations in medical weight loss.
- FDA approved for weight loss as Zepbound® (2023) — newer data, faster-evolving evidence
- Dual GLP-1 + GIP mechanism drives superior average efficacy in trials
- Some patients report improved tolerability at mid-range doses
- Compounded with B12 + B6 at TREVI
- Dr. Josie has observed patients who plateaued on semaglutide respond well to tirzepatide
The Physician's Perspective
"Which one should I choose?"
This is the most common question Dr. Josie hears in weight loss consultations — and the honest answer is: there is no universal right answer. The medication that produces the best outcome for any individual depends on factors that no quiz, comparison chart, or online forum can assess.
"I look at my entire toolchest. Semaglutide and tirzepatide are both excellent medications, but the right choice depends on your labs, your body composition, your history with other treatments, and your specific goals. This is exactly why you need a physician, not a one-size-fits-all online clinic."
— Dr. Josie Tenore, MD, MSc · TREVI Longevity & AestheticsAt TREVI, every patient starts with a comprehensive evaluation before a medication is ever selected. That evaluation includes:
Body Composition Analysis
InBody scan to assess lean mass, fat mass, and visceral fat — not just weight on a scale.
Comprehensive Bloodwork
Labs to identify hormonal imbalances, metabolic factors, and nutritional deficiencies that affect weight.
Medical History Review
Prior weight loss attempts, medications, contraindications, and family history all factor into the decision.
Treatment Goals
Weight loss targets, timeline, lifestyle factors, and long-term maintenance strategy.
For patients considering switching from semaglutide to tirzepatide — or who have plateaued on one medication — Dr. Josie evaluates the full clinical picture before making any change in protocol.
The TREVI Approach
Physician-Supervised. Personalized. Monitored.
TREVI uses compounded forms of both semaglutide and tirzepatide — not brand-name medications that are difficult to access and far more expensive. Compounding allows for the addition of B12 and B6, ensures patients receive fresh individual doses monthly, and keeps costs significantly lower than brand-name alternatives.
Every TREVI weight loss patient is monitored throughout their program. This is not a prescription-and-goodbye practice. Dr. Josie stays involved in dose adjustments, labs, body composition tracking, and long-term management.
Comprehensive Evaluation
InBody scan, bloodwork, full health history, and goal setting at your first consultation.
Personalized Protocol
Dr. Josie selects the medication — semaglutide or tirzepatide — and dosing schedule based on your specific profile.
Ongoing Monitoring
Regular check-ins, lab reviews, dose optimization, and body composition tracking throughout your program.
Highland Park, IL
Schedule Your Free Consultation
Speak with Dr. Josie about your weight loss goals, whether semaglutide or tirzepatide is right for you, and what a personalized TREVI program looks like. No commitment required.
*Clinical trial data represents population averages from the STEP (semaglutide, 68 weeks) and SURMOUNT (tirzepatide, 72 weeks) trials at maximum studied doses. Individual results vary significantly based on starting weight, adherence, lifestyle, and health profile. GLP-1 medications are prescription-only and must be used under the supervision of a licensed physician. This page is for informational and educational purposes only and does not constitute medical advice. TREVI Longevity & Aesthetics · 1800 Skokie Valley Rd Suite 210, Highland Park, IL 60035 · (847) 681-8821