Description
The Tesamorelin/Sermorelin Blend combines two GHRH receptor agonists with distinct structural and pharmacokinetic profiles in an equal-ratio formulation. Sermorelin is a 29-amino acid analog corresponding to the N-terminal GHRH(1-29) sequence, with a plasma half-life of approximately 11-12 minutes following intravenous administration. Tesamorelin is a full 44-amino acid GHRH sequence with a trans-3-hexenoic acid N-terminal modification that confers DPP-4 resistance and extends half-life to approximately 26-38 minutes following subcutaneous administration. Both compounds bind the same GHRH receptor (GHRHR) on anterior pituitary somatotrophs and activate the same Gs-coupled cAMP signaling cascade driving GH secretion. This is a critical mechanistic distinction from dual-pathway blends: Tesamorelin and Sermorelin are not complementary through independent receptor systems, but rather two agonists competing for and activating the same receptor class. The research value of this combination therefore lies in comparative receptor pharmacology: studying how two GHRHR agonists with different sequence lengths, DPP-4 resistance profiles, and half-lives behave when present simultaneously in GHRHR binding assays, somatotroph cell models, and pharmacokinetic characterization experiments.
Chemical Information
Tesamorelin Component:
- Chemical Name: Tesamorelin (trans-3-hexenoic acid-GHRH(1-44)-NH2)
- Also Known As: TH9507; Egrifta (FDA-approved form)
- Compound Class: Full-length GHRH analog; DPP-4-resistant N-terminal modification
- Length: 44 amino acids (full native GHRH sequence with N-terminal modification)
- Molecular Weight: approximately 5,136 Da
- Half-life: approximately 26-38 minutes (SC administration)
- FDA Status: Approved for HIV-associated lipodystrophy (Egrifta)
Sermorelin Component:
- Chemical Name: Sermorelin (GHRH 1-29 NH2)
- Also Known As: GRF 1-29; GHRH(1-29)
- Compound Class: N-terminal GHRH fragment analog
- Length: 29 amino acids (N-terminal GHRH sequence)
- Molecular Weight: approximately 3,357 Da
- Half-life: approximately 11-12 minutes (IV administration)
- DPP-4 vulnerability: susceptible to DPP-4 cleavage at Tyr-Ala N-terminus
Blend:
- Shared receptor target: GHRHR (growth hormone-releasing hormone receptor; Gs-coupled GPCR on pituitary somatotrophs)
- Ratio: Tesamorelin 5mg / Sermorelin 5mg or Tesamorelin 10mg / Sermorelin 10mg
- Production: Solid-phase peptide synthesis (SPPS) for both components
Applications
- Comparative GHRHR binding studies. Tesamorelin (44-AA, DPP-4-resistant) and Sermorelin (29-AA, DPP-4-susceptible) provide two structurally distinct agonists for the same receptor; comparative binding affinity, receptor occupancy, and displacement studies use both compounds to characterize how sequence length and N-terminal modification affect GHRHR engagement
- GHRHR pharmacokinetic characterization. The different half-lives (11-12 minutes for Sermorelin versus 26-38 minutes for Tesamorelin) create distinct receptor occupancy and cAMP signaling time-course profiles; researchers studying GHRHR desensitization, receptor recovery kinetics, and somatostatin feedback timing use both compounds to probe these dynamics at different timescales
- DPP-4 enzyme activity research. Sermorelin’s susceptibility to DPP-4 cleavage at the Tyr-Ala N-terminus versus Tesamorelin’s resistance from its N-terminal modification makes the two compounds useful in studies examining DPP-4 activity in cell culture systems and how enzymatic stability affects GHRHR agonist function duration
- GHRH analog structure-activity research. The 15-amino acid sequence difference between the two compounds (Sermorelin is 29 AA; Tesamorelin is full 44 AA) enables study of how the C-terminal extension and N-terminal modification affect receptor binding, signaling amplitude, and pharmacokinetic behavior in somatotroph cell models
- Important research design note. Because both compounds activate the same receptor class, this blend does not provide dual-pathway GH axis stimulation in the mechanistic sense of GHRH plus ghrelin receptor co-activation; researchers seeking orthogonal receptor pathway stimulation alongside GHRHR engagement should combine either compound with a GHSR-1a agonist rather than with another GHRHR agonist
Storage and Handling
Store lyophilized blend at -20C for long-term stability, or at 2-8C for short-term use. Protect from heat, moisture, and direct light. Reconstitute immediately before use and avoid repeated freeze-thaw cycles. Both components are susceptible to proteolytic degradation; Sermorelin is additionally susceptible to DPP-4 cleavage at its N-terminal Tyr-Ala sequence when reconstituted in biological systems containing DPP-4 activity.
Compliance Notice
Tesamorelin/Sermorelin Blend is for laboratory research use only. They are not for human or veterinary use and carry no therapeutic, diagnostic, or clinical indication. Note that Tesamorelin is FDA-approved as Egrifta for HIV-associated lipodystrophy. However, the research-grade compound in this blend is not equivalent to the approved pharmaceutical formulation. FDA has not evaluated this product. By purchasing this product, the buyer confirms that they will follow appropriate institutional safety procedures and use it exclusively for controlled research.
