Low StockOP-T
20mg | $199.00FDA-approved dual-agonist that engages GLP-1 and GIP receptors, with GIP-favoring potency.
The GIP arm acts directly on fat cells, triggering thermogenic processes absent in GLP-1-only compounds — which may explain the favorable body composition outcomes.
Head-to-head trials showed 20% weight reduction, with approximately 75% of mass lost coming from fat rather than lean tissue.
Made in USA•Purity: 99% HPLC
- Dual Pathway ActivationHits appetite control and insulin efficiency pathways together
- Fat Cell Energy BurnActivates a heat-generating process in fat cells that burns calories
- Better Fat:Muscle Ratio~75% of weight lost comes from fat, preserving more muscle than GLP-1 alone
- Improved Insulin EfficiencyBetter insulin response to meals means less insulin needed overall
1
For in-vitro laboratory research use only. Not for human consumption.
Research Status:FDA Approved
FDA-approved dual GLP-1/GIP agonist (Mounjaro/Zepbound) for T2D and obesity; extensive Phase 3 programs (SURPASS, SURMOUNT)
For laboratory research use only.
Tirzepatide is an FDA-approved dual-agonist — a single molecule that engages both GLP-1 (appetite regulation) and GIP (insulin efficiency and fat cell signaling) receptors. In the SURMOUNT-5 head-to-head trial, tirzepatide produced 20.2% weight loss versus semaglutide at 13.7% — 47% greater efficacy with a substantially better fat-to-lean ratio.
The GIP pathway is what sets it apart. GLP-1 receptors are not expressed in adipose tissue; GIP receptors are. This allows tirzepatide direct access to fat cell signaling unavailable to GLP-1-only compounds. A 2024 Cell Metabolism study identified the mechanism: GIP receptor activation triggers SERCA-mediated futile calcium cycling — ATP consumption without productive work, generating heat. This thermogenic process in white adipose tissue contributes to energy expenditure beyond appetite suppression.
SURMOUNT-1 (Obesity)
72-week Phase 3 trial in 2,539 adults with obesity (no diabetes): tirzepatide produced 16.0% (5 mg), 21.4% (10 mg), and 22.5% (15 mg) weight loss versus 2.4% with placebo. At the highest dose, approximately half of participants lost ≥20% of body weight.
Body Composition (DXA Substudy)
DXA analysis of 160 SURMOUNT-1 participants showed ~75:25 fat-to-lean mass loss ratio at the 15 mg dose — fat mass dropped 34%, lean mass dropped 11%. This ratio remained consistent across weight loss categories. In comparison, semaglutide produces ~60:40 in STEP 1 data, with approximately 40% of weight lost coming from lean mass.
SURMOUNT-5 (Head-to-Head vs Semaglutide)
Direct comparison in 751 adults: tirzepatide (max tolerated 10–15 mg) produced 20.2% weight loss versus semaglutide (max tolerated 1.7–2.4 mg) at 13.7% over 72 weeks. Same dosing frequency, same titration schedule. The 47% greater weight loss reflects the mechanistic difference.
SURPASS-2 (Type 2 Diabetes)
Open-label comparison against semaglutide 1 mg in 1,879 patients with T2DM: tirzepatide achieved greater HbA1c reduction (2.0–2.3% vs 1.86%) and 1.9–5.5 kg more weight loss depending on dose.
Diabetes Context
In people with type 2 diabetes, the body composition advantage shrinks. The fat:lean ratio becomes nearly identical to semaglutide (~87:13 vs ~86:14). This is attributed to the "incretin defect" — impaired GIP signaling in diabetics. Tirzepatide still produces more total weight loss, but the mechanism shifts from "better ratio" to "more total fat."
Liver Fat
MRI substudies showed ~47% relative liver fat reduction at the highest dose — attributed to weight loss and improved insulin sensitivity rather than direct hepatic effects (unlike glucagon-active compounds).
FDA approval is for obesity and type 2 diabetes, establishing safety and efficacy in those populations. The superior body composition ratio seen in non-diabetics diminishes in diabetics due to impaired GIP signaling. SURPASS-CVOT cardiovascular outcomes used an active comparator (dulaglutide) rather than placebo, limiting direct interpretation. The thermogenic mechanism was characterized in mouse models; human confirmation of futile calcium cycling specifically is pending. Like all GLP-1 class compounds, gastrointestinal side effects are common during titration.
- Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity. NEJM 2022.
- SURMOUNT-5 head-to-head trial. NEJM 2024.
- Yu M, et al. The GIP receptor activates futile calcium cycling in white adipose tissue. Cell Metabolism 2025.
- Look M, et al. Body composition changes during weight reduction with tirzepatide in SURMOUNT-1. Diabetes Obes Metab 2025.
For laboratory research use only.
This product ships as lyophilized (freeze-dried) powder. After reconstitution, the solution requires different storage conditions than the powder.
Reconstituted Solution
Refrigerate2–8°C (36–46°F)Up to 30 daysDo not freeze. Use within 30 days of mixing.
Lyophilized Powder
Refrigerated2–8°C (36–46°F)Weeks to months
Frozen−20°C (−4°F) or belowMonths to years
All peptides are HPLC-purified to ≥99% purity. Each lot includes a Certificate of Analysis (COA) with exact purity percentage, mass spectrometry data, and amino acid analysis.
Lyophilized peptides should be stored at -20°C for long-term storage or 2-8°C for short-term use. Once reconstituted, store at 2-8°C and use within 30 days. Avoid repeated freeze-thaw cycles.
This product is sold strictly for in-vitro laboratory research purposes only. It is not intended for human consumption and is not a drug, cosmetic, or food product.
Currently we ship within the United States only. International shipping is not available at this time.