Growth HormoneMetabolism6 min read
Tesamorelin in Lipodystrophy Research: 15 Years After FDA Approval
Tesamorelin has been FDA-approved since 2010. What has research learned since then? New findings on lipodystrophy, myosteatosis and MASLD.
MetabolismGLP-1
Tirzepatide: The Dual GLP-1/GIP Agonist Revolutionising Obesity Research
7 min read
What Makes Tirzepatide Unique?
Tirzepatide (LY3298176) is a synthetic peptide that simultaneously binds two distinct receptors: the GLP-1 receptor (Glucagon-Like Peptide-1) and the GIP receptor (Glucose-dependent Insulinotropic Peptide). This dual receptor activation fundamentally distinguishes tirzepatide from earlier GLP-1 monoagonists such as semaglutide.
The SURMOUNT trial series showed that tirzepatide administered weekly subcutaneously at 10–15 mg enabled a mean body weight reduction of up to 22.5 % after 72 weeks. These data were published in the New England Journal of Medicine in 2022.
Molecular Basis
Tirzepatide is based on the natural amino acid sequence of GIP but has been optimised through targeted modifications: a C18 fatty acid chain enables albumin binding and extends the half-life to approximately 5 days. Additional amino acid substitutions ensure balanced binding affinity at both receptors.
GIP receptor activation complements GLP-1-mediated insulin secretion through additional incretin effects. In adipose tissue, GIP signalling also stimulates lipogenic processes — paradoxically leading to improved lipid metabolism regulation — a mechanism that is still being intensively investigated.
SURMOUNT Trial Programme
Eli Lilly's SURMOUNT programme comprises multiple Phase 3 studies. SURMOUNT-1 (n=2,539) showed weight reductions of -20.9 % (10 mg) and -22.5 % (15 mg) after 72 weeks in participants without diabetes with a BMI ≥30. Tirzepatide is approved in Germany under the trade names Mounjaro (diabetes) and Zepbound (obesity). Studien Peptide offers tirzepatide as a high-purity lyophilised peptide for authorised research laboratories.
