For Research Purposes Only. This page summarizes published preclinical and clinical research. It does not constitute medical advice and is not a recommendation for human use.
Tirzepatide
Dual GIP/GLP-1 receptor agonist. FDA-approved as Mounjaro and Zepbound. Phase III trials demonstrated greater mean weight loss than GLP-1-only agents.
- Class
- Dual GIP + GLP-1 Agonist
- FDA Approvals
- Mounjaro, Zepbound
- Trial Phase
- Phase IV (post-market)
- Peak Trial Weight Loss
- 20.9% (SURMOUNT-1, 72 wks)
01 · Overview
Tirzepatide is a 39-amino-acid synthetic peptide that acts as a dual agonist at two incretin receptors: GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1). While GLP-1 receptor activation suppresses appetite, slows gastric emptying, and stimulates insulin secretion, GIP receptor activation is believed to complement these effects through additional appetite regulation and improved adipose tissue insulin sensitivity. The dual mechanism appears to produce a synergistic effect on weight reduction exceeding what GLP-1 receptor agonism alone achieves.
Tirzepatide was developed by Eli Lilly and advanced rapidly through clinical development. The SURPASS program established efficacy for type 2 diabetes (HbA1c reductions of ~2.0–2.5 percentage points), leading to FDA approval as Mounjaro in 2022. The SURMOUNT program then demonstrated unprecedented weight loss in obesity: SURMOUNT-1 (NEJM, 2022) reported a mean 20.9% body weight reduction at 72 weeks at the 15mg dose — exceeding the ~15% benchmark set by semaglutide's STEP-1 trial. Approval for chronic weight management followed as Zepbound in late 2023.
Tirzepatide is FDA-approved under two brand names: Mounjaro (type 2 diabetes) and Zepbound (chronic weight management in adults with obesity or overweight with comorbidities). Research-grade tirzepatide sold by peptide vendors is a synthetic peptide manufactured for laboratory research. It is not the pharmaceutical product, is not subject to pharmaceutical-grade manufacturing controls, and is not approved or intended for human use.
Sizes currently sold by tracked vendors: 1000mg, 100mg, 10mg, 1200mg, 120mg, 150mg, 15mg, 200mg, 20mg, 25mg, 2mg, 300mg, 30mg, 400mg, 40mg, 500mg, 50mg, 5mg, 600mg, 60mg, 65mg, 75mg, 800mg, 80mg.
02 · Research status
SURMOUNT-1 (Jastreboff et al., NEJM 2022): 20.9% mean weight reduction at 72 weeks (15mg dose) in adults with obesity. SURPASS-2 (Frías et al., NEJM 2021): superior glycemic control vs semaglutide 1mg in T2D. SURMOUNT-OSA (Malhotra et al., NEJM 2024): significant apnea improvement in obesity + OSA.
03 · Common research protocols
| Clinical titration (Mounjaro/Zepbound) | 2.5mg/wk × 4 wks → 5mg; escalate in 2.5mg steps ≥4 wks apart to max 15mg/wk |
| Administration (pharmaceutical) | Once-weekly subcutaneous injection (pre-filled pen) |
| Typical research vial sizes | 5mg, 10mg, 15mg |
| Reconstitution solvent | Bacteriostatic water; research vials require manual reconstitution unlike pharmaceutical pens |
Dosing above is from FDA-approved pharmaceutical labeling for Mounjaro and Zepbound. These protocols apply to pharmaceutical-grade tirzepatide manufactured under GMP conditions. Research-grade vials are not equivalent to pharmaceutical products. This information is for educational reference only.
Use the reconstitution calculator →04 · Storage & handling
Lyophilized research tirzepatide should be stored at −20°C. Once reconstituted, store at 4°C and use within 28 days. Pharmaceutical pens (Mounjaro, Zepbound) have different storage requirements — do not confuse them with research vials.
05 · What to look for when buying
- Tirzepatide is a 39-amino-acid peptide — moderately complex to synthesize correctly. Third-party HPLC purity verification is important; Finnrick has tested tirzepatide from several vendors.
- Confirm the stated vial size against the price: tirzepatide is commonly sold in 5mg, 10mg, and 15mg vials and per-mg pricing drops significantly at larger sizes. Compare the per-mg column rather than vial price.
- Verify COA specifies HPLC purity, not just mass spectrometry identity. For a molecule this size, truncated sequences are a meaningful synthesis risk.
- Research-grade tirzepatide lacks the manufacturing controls applied to Mounjaro/Zepbound. Prioritize vendors with multiple independent third-party test results and recent COA dates.
06 · Price comparison
Prices last checked Oct 26, 2026| Vendor | Sizes | Price range | Best $/mg | Stock |
|---|---|---|---|---|
| SaiyanMed | 8 | $53.00 – $244.00 | $0.41 | In stock |
| Zen Peptides | 7 | $60.00 – $245.00 | $0.41 | In stock |
| HkRoids | 8 | $57.00 – $251.00 | $0.42 | In stock |
| Reta-Peptide | 1 | $145.00 | $0.48 | In stock |
| UWA Elite Peptides | 9 | $70.00 – $500.00 | $0.50 | In stock |
| Oupeptide | 7 | $95.00 – $340.00 | $0.57 | In stock |
| Royal Peptides | 17 | $28.80 – $1080.00 | $0.90 | In stock |
| Go Alpha Labs | 4 | $59.49 – $839.99 | $1.40 | In stock |
| Peptide Partners | 5 | $208.00 – $1800.00 | $1.50 | In stock |
| Sunrise BioResearch | 3 | $56.66 – $509.93 | $1.70 | In stock |
| NUPEPS | 3 | $80.00 – $114.00 | $1.90 | In stock |
| Steady Meds | 10 | $35.00 – $185.00 | $2.31 | In stock |
| NextechLabs | 5 | $64.99 – $926.24 | $2.71 | In stock |
| Amino Amigos | 4 | $59.99 – $1099.00 | $2.75 | In stock |
| Nextwave Peptides | 10 | $59.00 – $406.00 | $3.79 | In stock |
| Coastal Peptides | 5 | $54.00 – $239.00 | $3.98 | In stock |
| Hydro Research | 13 | $45.00 – $2550.00 | $4.17 | In stock |
| Prime Peptides | 3 | $100.00 – $260.00 | $4.33 | In stock |
| PeptiSlim | 8 | $80.00 – $330.00 | $5.50 | In stock |
| Loti Labs | 4 | $59.99 – $289.99 | $5.80 | In stock |
| Simple Peptide | 1 | $65.10 | $6.51 | In stock |
| Accelerate Labs | 1 | $65.99 | $6.60 | In stock |
| Alpha-Gen | 1 | $80.00 | $8.00 | In stock |
| Injectify | 1 | $98.99 | $9.90 | In stock |
| Pure Rawz | 3 | $191.15 – $625.57 | $10.43 | In stock |
| Behemoth Labz | 1 | $341.88 | $34.19 | In stock |
26 vendors tracked · prices scraped weekly from vendor sites · open full comparison table →
07 · Third-party purity data
Full data at finnrick.com ↗Independent HPLC test results — averages across multiple samples.
08 · Frequently asked questions
What is Tirzepatide?
Tirzepatide is a 39-amino-acid synthetic peptide that acts as a dual agonist at two incretin receptors: GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1).
Is tirzepatide FDA approved?
Yes — as Mounjaro (type 2 diabetes, 2022) and Zepbound (chronic weight management, 2023). Research-grade tirzepatide sold by vendors is not the pharmaceutical product and is not approved for human use.
How does tirzepatide differ from semaglutide?
Tirzepatide activates both GIP and GLP-1 receptors, while semaglutide targets GLP-1 only. In head-to-head-relevant trial data, tirzepatide produced greater mean weight loss (20.9% in SURMOUNT-1 vs ~15% in semaglutide STEP-1), though the trials differed in duration and population.
How much does Tirzepatide cost?
Across 26 vendors tracked by PepVendors, Tirzepatide currently runs $0.41–$34.19 per mg at each vendor's best price tier (26 showing in stock). Vial prices and size tiers vary — the live comparison table on this page lists current pricing.