We use essential cookies (authentication, your saved goals/stack) by default. With your permission we’ll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more about cookies
Tirzepatide (GIP/GLP-1 receptor agonist)
An FDA-approved prescription medication (Mounjaro for type 2 diabetes, Zepbound for obesity and obstructive sleep apnea), not a dietary supplement. Honest appraisal: in head-to-head phase-3 trials it is the most effective approved weight-loss drug to date — up to ~21% body-weight loss over 72 weeks and superior to semaglutide — but it is a real medicine with real risks: a US FDA boxed warning for thyroid C-cell tumors, common GI side effects, and pancreatitis/gallbladder signals. Do not source or use it outside a prescription.
Prescription medication — not a dietary supplement
Tirzepatide is a prescription (or investigational) drug, not a supplement. It is included here for reference because people research and discuss it (often used off-label) — not as a recommendation. Take it only under a qualified clinician's supervision and only as prescribed; do not source it from grey-market vendors, where identity, purity, and dosing are unverified. The evidence below reflects its clinical trials.
What the evidence says
Tirzepatide doesn't have enough studies with structured effect-size data yet to pool a verdict. Browse the studies below for individual findings.
Most evidence is from high-quality meta-analyses and randomised trials published 2021–2026 with a typical study size of 1,879 participants.
Based on 133 studies · 42 meta-analyses · 58 RCTs · 69,040 total participants
Confidence
High confidenceBy outcome
An FDA-approved drug, not a supplement: large phase-3 RCTs (SURPASS, SURMOUNT) and meta-analyses show strong, head-to-head-superior glycemic and weight-loss efficacy, tempered by real prescription-only risks.
44 randomised trials
91% were about Tirzepatide in an audit of 44 of them
Every randomised or controlled trial of Tirzepatide indexed in PubMed, not a hand-picked subset. Meta-analyses and systematic reviews are deliberately excluded from this count: most of them cover many compounds at once, so counting them would inflate it.
PubMed · as of Sep 2026
207 trials ongoing or recruiting · 92 completed on ClinicalTrials.gov
47 of the completed trials have posted results
Registered trials show research momentum for Tirzepatide, not proof of effect — a registration is a plan, and posted results are sponsor-reported, not peer-reviewed. They are never counted toward the evidence rating above.
Browse these trials on ClinicalTrials.govClinicalTrials.gov · as of Nov 2026
Tirzepatide is a once-weekly subcutaneous peptide that activates two incretin receptors at once — the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor.
This dual mechanism enhances glucose-dependent insulin secretion, improves insulin sensitivity, slows gastric emptying, and powerfully suppresses appetite.
It is an FDA-approved prescription drug, marketed as Mounjaro (approved 2022 for type 2 diabetes) and Zepbound (approved 2023 for chronic weight management and, subsequently, for moderate-to-severe obstructive sleep apnea in adults with obesity).
Its evidence base is genuinely strong and built on large, double-blind, phase-3 randomized trials. In the SURPASS diabetes program, tirzepatide lowered HbA1c by roughly 1.9-2.6 percentage points and outperformed placebo, titrated basal insulin (degludec and glargine), and — head-to-head in SURPASS-2 — semaglutide 1 mg.
In the SURMOUNT obesity program, SURMOUNT-1 produced mean weight reductions of -15.0%, -19.5%, and -20.9% at 5, 10, and 15 mg over 72 weeks (vs -3.1% placebo), among the largest ever seen with a pharmacotherapy; SURMOUNT-5 then showed superiority over maximally-dosed semaglutide (-20.2% vs -13.7%).
SURMOUNT-OSA showed large reductions in the apnea-hypopnea index in obese adults with obstructive sleep apnea. This is not a supplement and should never be framed as one.
The most frequent adverse effects are gastrointestinal (nausea, diarrhea, vomiting, constipation), mostly during dose escalation; in the US, FDA labeling carries a boxed warning for thyroid C-cell tumors (contraindicated under that US label with a personal or family history of medullary thyroid carcinoma or MEN2), plus signals for pancreatitis and gallbladder disease, and a portion of the weight lost is lean mass.
The FDA has repeatedly warned about compounded and grey-market tirzepatide of unverified identity, purity, and dose. It is appropriate only under medical supervision for an approved indication.
Tirzepatide is a single peptide that simultaneously activates the GIP and GLP-1 receptors — the basis for its 'dual incretin' or 'twincretin' classification — producing additive effects on glucose handling and appetite.
Enhances glucose-dependent insulin release and improves insulin sensitivity, lowering HbA1c and fasting glucose without the hypoglycemia risk seen with insulin or sulfonylureas.
Acts on central appetite circuits and slows gastric emptying, reducing food intake — the primary driver of the large weight loss seen in the SURMOUNT trials.
How Tirzepatide works — from molecular targets to health outcomes. Click an edge to see supporting research.This visualization is in beta — pathways are being refined and expanded.
Contraindicated — under the US label, which carries a US FDA boxed warning for thyroid C-cell tumors. In Germany or Austria, the current product information for the exact medicine applies.
Use with caution or avoid; monitor for pancreatitis symptoms.
Contraindicated — discontinue before a planned pregnancy.
Hypoglycemia risk — concomitant doses usually need reduction under medical supervision.
Slowed gastric emptying may reduce the efficacy of oral contraceptives — a non-oral or backup contraceptive method is advised when starting and after each dose escalation.
Additive glucose-lowering raises hypoglycemia risk; doses of insulin/sulfonylureas often need reduction.
Delayed gastric emptying can alter the absorption of co-administered oral drugs; clinically significant mainly for narrow-therapeutic-index agents.
Tip: Contact your treating team about the symptom and follow the product-specific instructions. Do not reduce, split, stop or restart prescribed treatment solely to continue this experiment.
Tip: Hydration; slower escalation
Tip: Slower escalation; dietary adjustment
Tip: Fiber, fluids, activity
Tip: Expected effect; ensure adequate protein intake to limit lean-mass loss
Tip: Stop and seek care for severe persistent abdominal pain; avoid in those with a pancreatitis history
Tip: Seek care for right-upper-quadrant pain, fever, or jaundice
Tirzepatide has an evidence score of 7.8/10 — strong evidence based on 133 indexed studies, including 2 meta-analyses. An FDA-approved prescription medication (Mounjaro for type 2 diabetes, Zepbound for obesity and obstructive sleep apnea), not a dietary supplement. Honest appraisal: in head-to-head phase-3 trials it is the most effective approved weight-loss drug to date — up to ~21% body-weight loss over 72 weeks and superior to semaglutide — but it is a real medicine with real risks: a US FDA boxed warning for thyroid C-cell tumors, common GI side effects, and pancreatitis/gallbladder signals. Do not source or use it outside a prescription. Representative study: PMID 38613667.
Dosing for Tirzepatide: Once-weekly subcutaneous injection, started at 2.5 mg and escalated by 2.5 mg every 4 weeks to a maintenance dose of 5, 10, or 15 mg (per the prescribing physician and approved indication). Individual needs vary, so check the right dose for you with a healthcare provider.
Timing is flexible for Tirzepatide — consistent daily use matters more than the time of day. Administered once weekly, with or without food, on the same day each week.
Tirzepatide should be used with caution — talk to a healthcare provider before taking it. Reported side effects include pancreatitis, gallbladder disease (cholelithiasis/cholecystitis), nausea. How often they occur is not established for all of them. Use caution if any of these apply to you: Personal or family history of medullary thyroid carcinoma (MTC) (a contraindication under the US label); Multiple endocrine neoplasia syndrome type 2 (MEN2) (a contraindication under the US label); History of pancreatitis (use with caution / avoid).
Semaglutide
Too few graded studiesAn FDA-approved GLP-1 receptor agonist (Ozempic/Rybelsus for type 2 diabetes, Wegovy for chronic weight management) with genuinely strong, large-RCT evidence for glycemic control and substantial weight loss, plus a cardiovascular-outcomes benefit. Honest appraisal: this is a real prescription medicine with real efficacy AND real risks — a US FDA boxed warning for thyroid C-cell tumors, pancreatitis and gallbladder risk, very common GI side effects, and growing concern about grey-market/compounded versions. It is a prescription drug, not a supplement, and is never auto-recommended.
Liraglutide
Too few graded studiesAn FDA-approved, once-daily GLP-1 receptor agonist (Victoza for type 2 diabetes, Saxenda for chronic weight management). Honest appraisal: a real prescription medicine with genuinely strong large-RCT evidence for glycemic control and moderate weight loss, plus a cardiovascular-outcomes benefit (LEADER). It also carries real risks — a US FDA boxed warning for thyroid C-cell tumors, pancreatitis and gallbladder risk, very common GI side effects, and lean-mass loss with weight loss. It is a prescription medicine, NOT a supplement, and is not auto-recommended.
Orforglipron
Too few graded studiesAn ORAL, non-peptide small-molecule GLP-1 receptor agonist for obesity, also studied in type 2 diabetes — the headline is the convenience of a once-daily pill (no injection, no cold chain, no food/water restrictions) delivering GLP-1-class glycemic and weight benefit. In the US, orforglipron is approved as Foundayo for long-term weight management in adults with obesity, or overweight with at least one weight-related condition, together with a reduced-calorie diet and increased physical activity. FDA approval was granted on 1 April 2026. An EMA list dated 5 October 2026 places orforglipron under evaluation. Honest appraisal: the phase-2 data are strong and the phase-3 read-outs (ATTAIN/ACHIEVE) are promising, but it has the full GLP-1-class side-effect burden (very common dose-dependent nausea/vomiting/diarrhea, higher discontinuation than injectables in some comparisons), the US label carries a boxed warning about thyroid C-cell tumours, and long-term outcomes are unsettled. It is NOT a dietary supplement.
Mazdutide
Too few graded studiesAn investigational once-weekly injectable GLP-1 and glucagon receptor dual agonist (an oxyntomodulin analogue, IBI362/LY3305677) developed mainly in China by Innovent and Eli Lilly for obesity and type 2 diabetes. Honest appraisal: real phase-2 and phase-3 randomized trials show clinically meaningful weight loss (~12-17% at higher doses) and HbA1c reduction, but the evidence is almost entirely single-region (Chinese) and recent. It was approved in China in 2025 — it is NOT FDA-approved and is not available or approved in the West. It is a prescription drug, not a dietary supplement.
Explore: Best supplements for Vitality & Longevity
Reviewed by Dr. Baher Al Hakim · Last reviewed June 2026 · evidence from 133 studies · how we score · editorial policy
This information is for educational purposes only. It is not a substitute for professional medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication.
Tap node to isolate • Pinch to zoom • Tap edge for research