The Thrive After Oz Library

GLP-1, Peptide & Muscle Preservation Guides

Free, medically reviewed resources on GLP-1 medications like Ozempic, Wegovy, Mounjaro and Zepbound, peptide therapy and sourcing safety, and how to lose fat — not muscle — on semaglutide or tirzepatide.

Medically reviewed Interactive tools included Updated for 2026

Quick answers

The short version, before you dive into a full guide.

Which GLP-1 is best for weight loss?
Tirzepatide (Zepbound, Mounjaro) has produced the greatest average weight loss in clinical trials — up to ~21% of body weight — ahead of semaglutide (Wegovy) at ~15%. See the GLP-1 Guide for the full comparison.
How do I avoid muscle loss on a GLP-1?
Hit 1.2–1.6 g of protein per kg of goal body weight daily, spread leucine across 3–4 meals, and lift 2–3x per week. The Muscle-Sparing Protocol calculates your exact targets.
Are peptides legal to buy in 2026?
Some — like certain growth-hormone secretagogues — are available via prescription through licensed 503A compounding pharmacies; others are unregulated research chemicals. The Peptides Guide maps the legal status compound by compound.
How do I know a peptide source is legitimate?
Require a batch-specific, third-party certificate of analysis (COA) from an ISO 17025-accredited lab, and verify it with the lab directly. Our COA verification checklist walks through it step by step.

How to use these guides

Start with the GLP-1 Guide if you're new to these medications. Explore the Peptides Guide to understand adjunct therapies. Then follow the Muscle-Sparing Protocol to make sure the weight you lose is fat — not the lean mass that keeps your metabolism strong. Each guide links back here so you can move between them at your own pace.

Guides FAQ

Common questions about GLP-1s, peptides, and what these guides cover.

Educational content only — not medical advice. Always consult a licensed clinician before starting, stopping, or combining any medication or peptide therapy.

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