GLP-1 vs RETA (Retatrutide) — Which Weight Loss Program Is Right for You?

If you've been researching medical weight loss, you've probably heard about GLP-1 medications like Semaglutide and Tirzepatide. But there's a newer, more powerful option that most clinics aren't offering yet: Retatrutide — also known as RETA. At Lean Lab Pasadena, we offer all three. Here's how to know which one is right for you.

What Is a GLP-1 Medication?

GLP-1 stands for Glucagon-Like Peptide-1 — a hormone your gut naturally produces after eating. GLP-1 receptor agonists mimic this hormone to reduce appetite, slow gastric emptying, and improve blood sugar regulation. The two most well-known GLP-1 medications are:

• Semaglutide — A single-receptor GLP-1 agonist. Clinical trials have reported 15–17% average body weight reduction; individual results vary. Once-weekly injection. Starting at $499/month at Lean Lab.
• Tirzepatide — A dual-receptor GLP-1/GIP agonist. Targets two pathways simultaneously for greater appetite suppression and metabolic effects. Clinical trials showed up to 22.5% body weight reduction. Starting at $599/month at Lean Lab.

Both are powerful, well-studied medications with strong safety profiles. They're an excellent starting point for most patients.

What Is RETA (Retatrutide)?

Retatrutide — which we call RETA at Lean Lab — is the world's most advanced weight loss peptide. Unlike Semaglutide (single receptor) or Tirzepatide (dual receptor), RETA is a triple-receptor agonist that simultaneously targets:

• GLP-1 receptors — Appetite suppression and blood sugar control
• GIP receptors — Enhanced metabolic effects and fat burning
• Glucagon receptors — Increased energy expenditure and direct fat mobilization from adipose tissue

In Phase 2 clinical trials, Retatrutide produced up to 24.2% body weight reduction — the highest ever recorded for a weight loss medication. Patients on the highest dose lost an average of 58 lbs over 48 weeks.

RETA is available at Lean Lab starting at $699/month (2mg dose) and is offered in month-to-month, 3-month, 6-month, and 12-month membership packages.

GLP-1 vs RETA: Side-by-Side Comparison

Who Should Choose GLP-1 (Semaglutide or Tirzepatide)?

GLP-1 medications are an excellent choice if you:

• Are new to medical weight loss and want to start with a well-studied medication
• Have 20–50 lbs to lose and want steady, sustainable progress
• Have type 2 diabetes or insulin resistance (GLP-1s have strong metabolic benefits)
• Are working with a tighter budget and want to start at a lower price point
• Prefer a gentler appetite suppression experience

Who Should Choose RETA (Retatrutide)?

RETA is the right choice if you:

• Have significant weight to lose (50+ lbs) and want maximum results
• Have tried GLP-1 medications before and hit a plateau
• Want the most advanced, cutting-edge weight loss therapy available
• Are committed to a structured program with medical oversight
• Want the added benefit of direct fat mobilization through glucagon receptor activation

What Lean Lab Offers That Others Don't

Regardless of which medication you choose, every Lean Lab program includes:

• Monthly provider visits with a licensed clinician (not a chatbot or questionnaire)
• Comprehensive lab panels to monitor safety and optimize dosing
• Styku 3D body composition scans to track fat vs. muscle loss
• Personalized nutrition guidance and supplement recommendations
• Access to our medical team between visits
• Membership packages with significant savings (save up to $3,200 on 12-month plans)

How to Get Started

The best way to determine which program is right for you is a personalized consultation with our medical team. We'll review your health history, goals, and lab results to make a recommendation tailored to your biology — not a one-size-fits-all protocol.