GLP-1 Drug Guides
Evidence-based guides to every GLP-1 drug — semaglutide, tirzepatide, liraglutide, and emerging options. Comparisons, mechanisms, dosing protocols, and clinical trial breakdowns.
Drug comparisons
Wegovy vs Zepbound: What the Head-to-Head Trial Data Actually Shows
SURMOUNT-5, the first head-to-head trial of tirzepatide and semaglutide for obesity, published in NEJM in May 2025, reported a 6.5-percentage-point gap in mean weight loss at 72 weeks. Here is what the data says, what it does not say, and where the comparison still depends on the patient in front of the prescriber.
Tirzepatide vs Semaglutide: Direct Comparison of Weight Loss, Side Effects, and Cost
Tirzepatide (Mounjaro/Zepbound) and semaglutide (Ozempic/Wegovy) are the two dominant GLP-1-class obesity drugs. Head-to-head comparison data exists. Tirzepatide produces larger average weight loss; semaglutide has a longer safety record. Here is a direct comparison across every relevant dimension.
Wegovy vs Mounjaro: Comparing Semaglutide and Tirzepatide for Weight Loss
Wegovy (semaglutide 2.4 mg) is approved for obesity; Mounjaro (tirzepatide) is approved for T2D but widely used off-label for weight loss. They are different molecules with different mechanisms. Head-to-head data now exists. Here is how they compare for patients choosing between them.
Ozempic vs Wegovy: They're the Same Drug — Here's What Actually Differs
Ozempic and Wegovy both contain semaglutide — the same active molecule. The differences are the approved dose (Wegovy goes to 2.4 mg; Ozempic stops at 2 mg), the FDA indication (T2D vs obesity), and therefore the insurance coverage. Here is what this means for patients.
Ozempic vs Mounjaro: Two Different Mechanisms, Not Just Two Different Drugs
Ozempic activates one hormone receptor. Mounjaro activates two — GLP-1 and GIP. That second mechanism does things GLP-1 alone cannot, including improving insulin sensitivity in fat tissue independent of weight loss. Here is what the head-to-head data shows.
Mounjaro vs Zepbound: Same Drug, Two Different Approved Uses
Mounjaro and Zepbound contain the same active ingredient — tirzepatide — made by Eli Lilly. The difference is which condition is on the FDA label, and that single distinction controls insurance coverage.
Ozempic vs Wegovy: What Is the Actual Difference? (2026)
Ozempic and Wegovy are the same drug — semaglutide — made by the same company. The difference is the approved indication, the maximum dose, and which insurance will pay for it.
Saxenda vs Wegovy: Old-Generation vs New-Generation GLP-1 for Weight Loss
Both are injectable GLP-1 drugs for obesity by Novo Nordisk. Saxenda is a daily injection of liraglutide with 8–9% weight loss. Wegovy is a once-weekly injection of semaglutide with 15–17% weight loss. There is a clear efficacy winner.
Rybelsus vs Wegovy: Same Drug, Very Different Doses and Outcomes
Rybelsus and Wegovy are both semaglutide made by Novo Nordisk. The oral version produces substantially less weight loss than the injection — not because the molecule is different, but because the gut absorbs very little of a peptide taken by mouth.
Liraglutide vs Semaglutide: The GLP-1 Drug That Came Before Ozempic
Liraglutide (Victoza, Saxenda) was the dominant GLP-1 before semaglutide arrived. Semaglutide is more potent, dosed weekly rather than daily, and produces roughly twice the weight loss. Here is what the shift meant and where liraglutide still appears.
CagriSema vs Tirzepatide: REDEFINE 4 Head-to-Head Results Explained
CagriSema achieved 23% weight loss in head-to-head versus tirzepatide's 25.5%. It did not meet the non-inferiority threshold — but 23% weight loss is not failure. Here is what the trial actually showed and what it means for patients.
Orforglipron vs Semaglutide: The First Oral GLP-1 You Don't Have to Fast For
Orforglipron (Foundayo) is a once-daily oral GLP-1 pill that can be taken any time, with or without food — unlike oral Wegovy which requires a strict empty-stomach protocol. Here is what it offers vs injectable and oral semaglutide.
GLP-1 Drugs vs Bariatric Surgery: A Direct Comparison of Weight Loss, Risks, and Long-Term Outcomes
Bariatric surgery achieves larger average weight loss than GLP-1 drugs but carries surgical risks, requires permanent anatomical changes, and is irreversible. GLP-1 drugs are non-invasive, reversible, and increasingly closing the efficacy gap. Here is a direct comparison across every relevant dimension.
GLP-1 Side Effects: Which Drug Has the Fewest — and Why
Nausea, vomiting, constipation, and diarrhoea affect 20–44% of GLP-1 patients. The rates are not identical across drugs. Tirzepatide appears to have modestly lower GI side effects than semaglutide despite superior weight loss. Here is a complete side effect comparison across the main GLP-1 drugs.
How they work
How GLP-1 Drugs Work: An Evidence-Backed Mechanism Guide
GLP-1 receptor agonists don't suppress appetite — they extend a hormonal signal your body already makes after every meal. Here's how the mechanism actually works, what mono / dual / triple agonism means, and how long each drug stays in your system.
How Tirzepatide Works: The Dual GLP-1 + GIP Mechanism Explained
Tirzepatide activates two hormone receptors, not one. Here is what GIP does that GLP-1 alone cannot — and why some people respond to tirzepatide after semaglutide stopped working.
CagriSema: Novo Nordisk's GLP-1 + Amylin Drug — NDA Status, Trial Data, and What It Changes
CagriSema (semaglutide + cagrilintide) filed for FDA approval in December 2025. Here is the trial data, how the amylin mechanism differs from GLP-1, and what approval would mean for patients.
Orforglipron (Foundayo): Lilly's Oral GLP-1 Pill — FDA Approval, Trial Results, and What to Expect
Orforglipron (Foundayo) is Lilly's oral non-peptide GLP-1 pill, FDA-approved April 1, 2026. No food restrictions, $149/mo. ATTAIN trial data, comparisons to Wegovy and Zepbound.
GLP-1 Clinical Trials Explained: STEP, SURMOUNT, SELECT, and What They Proved
The STEP trials proved semaglutide for obesity. SURMOUNT proved tirzepatide. SELECT proved cardiovascular benefit. FLOW proved kidney protection. Understanding what each trial showed — and what it didn't — puts the GLP-1 clinical claims in context.
Dosing and administration
Wegovy Dose Escalation Schedule: The Official Titration Protocol Explained
Wegovy (semaglutide 2.4 mg) uses a structured 16-week dose escalation before reaching the maintenance dose. The protocol exists to reduce GI side effects. Here is the exact schedule, what each stage feels like, and when it is appropriate to pause or slow the escalation.
Zepbound and Mounjaro Dose Escalation Schedule: The Official Tirzepatide Titration Guide
Tirzepatide (Zepbound for obesity, Mounjaro for T2D) uses a structured dose escalation from 2.5 mg to a maximum of 15 mg over 20 weeks. The titration reduces GI side effects during initiation. Here is the complete schedule, what each stage involves, and how to manage side effects.
How to Inject Semaglutide (Wegovy/Ozempic): Step-by-Step Pen Guide
Semaglutide (Wegovy and Ozempic) comes in pre-filled auto-injector pens. The injection is straightforward, but several common mistakes affect drug delivery, tolerability, and injection site reactions. Here is the correct technique from the prescribing label and clinical experience.
Who Qualifies for GLP-1 Drugs: BMI Criteria, Comorbidities, and Contraindications
GLP-1 drugs are approved for specific BMI thresholds and indications. The criteria for Wegovy and Zepbound differ slightly from Ozempic and Mounjaro. There are also absolute contraindications that disqualify some patients. Here is the complete eligibility picture.
GLP-1 Drugs and Metformin: Can You Take Both, and Should You?
Metformin is the first-line T2D medication. GLP-1 drugs are often added to metformin as combination therapy. The two drugs have complementary mechanisms and additive glucose-lowering effects. Here is what the combination does, whether it's safe, and when to stop one in favour of the other.
Compounding
Compounded Semaglutide vs Wegovy/Ozempic: What Is and Isn't Different
Compounded semaglutide contains the same active ingredient as Wegovy and Ozempic but is produced by a compounding pharmacy rather than Novo Nordisk. Price is the major difference — compounded versions cost 70–85% less. Regulatory status, quality assurance, and what's actually in the vial also differ. Here is a complete comparison.
Compounded Tirzepatide vs Zepbound/Mounjaro: The Complete Comparison
Compounded tirzepatide is available at $299–$449/month versus Zepbound's $1,060 list price. The same active molecule, different manufacturing pathway. Here is what differs between compounded and branded tirzepatide, and what changed when the FDA shortage designation lifted.
Compounded vs Brand-Name GLP-1: The Legal and Practical Difference, May 2026
Brand-name and compounded GLP-1s are not the same product on a different label. We map the legal pathway, what's in the bottle, what the trials actually tested, and what FDA has flagged.
Best drug for your goal
Best GLP-1 Drug for Weight Loss in 2026: A Data-Driven Comparison
Tirzepatide vs semaglutide head-to-head: SURMOUNT-5 data, real-world outcomes, cost by path, and how to decide which GLP-1 fits your situation.
Best GLP-1 for Type 2 Diabetes in 2026: Comparing What the Data Shows
Tirzepatide (Mounjaro) produces the strongest A1C reductions and weight loss of any GLP-1 approved for T2D. Semaglutide (Ozempic) has an approved cardiovascular risk-reduction indication that tirzepatide does not. The right choice depends on your clinical picture.
More
Compounded to Brand Dose Conversion: Turning Your "Units" Into a Wegovy or Zepbound Dose
"I was taking 25 units" tells a brand prescriber almost nothing — units measure volume, not dose. Here is the one calculation that converts your compounded semaglutide or tirzepatide into a true weekly milligram figure, why the same units can mean three different doses, and how to map the result onto the Wegovy or Zepbound ladder.
GLP-1 Side Effects: What the Trials Report, What Patients Experience, and What Helps
Nausea is the headline side effect of semaglutide and tirzepatide, but it's neither the most dangerous nor the most universal. Here are the incidence rates from STEP 1, SURMOUNT-1 and SELECT; what each side effect actually feels like; what helps; and the specific signs that mean call your prescriber today.
Wegovy vs Saxenda vs Ozempic: A Three-Way Comparison (May 2026)
All three are Novo Nordisk GLP-1 injections, but they serve different purposes. Wegovy is the FDA-approved weight-loss drug. Ozempic is the diabetes drug used off-label for weight loss. Saxenda is the older daily GLP-1, now largely superseded. Here is how they compare on efficacy, dosing, cost, and who each is actually for.
Who Shouldn't Take GLP-1 Drugs: Contraindications, Cautions, and Honest Patient Profiles
The FDA labels for Wegovy and Zepbound name a short list of absolute contraindications, a longer list of warnings, and several patient profiles where the risk-benefit calculation is genuinely uncertain. This is the sourced version, written for patients who want to know if they're a candidate before a 15-minute telehealth intake decides for them.
Zepbound vs Mounjaro for Weight Loss: Same Drug, Different Labels (May 2026)
Zepbound and Mounjaro both contain tirzepatide — the same GIP/GLP-1 dual agonist made by Eli Lilly. Which one you get depends almost entirely on your diagnosis and your insurance plan, not on the drug itself.