Tesamorelin (stabilised GHRH 1-44 analogue) — 5 mg

A stabilized synthetic analogue of human GHRH (1-44), carrying an N-terminal trans-3-hexenoyl group that slows its enzymatic degradation. Studied as a tool for selective GHRH-R activation and for investigating pulsatile GH secretion in preclinical models. 5 mg vial, lyophilized powder, ≥99% HPLC purity verified by third-party analysis. A reagent for laboratory research use only, excluding any human or veterinary use.

Research areas

• Stabilised GHRH-R signalling
• GH / IGF-1 axis (models)
• Lipid metabolism (models)

Technical data

What the trans-3-hexenoyl group changes against other GHRH analogues

These compounds all target the same receptor, which does not make them interchangeable. Two verifiable criteria separate them: sequence length and stabilisation method.

Endogenous human GHRH is 44 amino acids, but its activity resides in the 1-29 fragment — hence the truncated analogues: sermorelin is GHRH(1-29), CJC-1295 a GHRH(1-29) analogue with four substitutions. Tesamorelin keeps the full 1-44 sequence, and mass settles it at a glance: ≈ 5,136 Da here against roughly 3.4 kDa for the 1-29 analogues.

Native GHRH is degraded within minutes by dipeptidyl peptidase 4 (DPP-4), which cleaves the bond between tyrosine 1 and alanine 2 and releases an inactive 3-44 fragment. Two protection strategies exist: substituting residue 2 with D-alanine (CJC-1295, Mod GRF 1-29), or acylating tyrosine 1 — tesamorelin's trans-3-hexenoyl group.

That group is therefore a chemical shield over the cleavage site, not a circulatory retention system. It is the nuance the CJC-1295 comparison loses: tesamorelin resists DPP-4 far better than native GHRH, but its plasma half-life stays in the tens of minutes — nothing like the 5.8 to 8.1 days reported for an albumin-conjugated DAC analogue (Teichman et al., 2006).

Mechanism studied

The target is the GHRH receptor (GHRH-R), a class B G-protein-coupled receptor expressed by anterior pituitary somatotrophs. Binding activates Gαs → adenylate cyclase → cAMP → protein kinase A, with CREB phosphorylation, calcium influx and exocytosis of GH granules.

The experimentally important point is position in the cascade: a GHRH-R agonist acts upstream of the pituitary, so the secretion it triggers remains subject to somatostatin tone and IGF-1 negative feedback, and keeps its pulsatile character in models — unlike direct exogenous GH.

What the literature shows

Tesamorelin has been through a genuine clinical trial programme — but those trials concern an approved pharmaceutical product, distinct from the reagent sold here. A randomised trial published by Falutz et al. in the New England Journal of Medicine in 2007 evaluated that medicine in patients with HIV-associated lipodystrophy, reporting a reduction in visceral adipose tissue on imaging, and led to a marketing authorisation in that indication.

The distinction is not a formality: that medicine is manufactured and controlled to pharmaceutical standards, for a medically supervised patient population. None of that applies to the product on this page, a laboratory reagent with no medicinal status and no human use.

What the literature does not show:

• No benefit persisting after discontinuation: in the published trials on the medicine, the visceral adipose tissue effect regressed once administration stopped.
• No data outside the supervised clinical setting, and no evaluation of the research reagent as such.
• A documented rise in IGF-1, requiring laboratory monitoring in the clinical setting — a limit of the data, not a parameter applying to the reagent.
• Preclinical work is largely rodent-based, with species differences in the somatotropic axis that call for caution.

Reconstitution: a worked example

With 2 mL of bacteriostatic water in a 5 mg vial: 5 mg ÷ 2 mL = 2.5 mg/mL, i.e. 2,500 mcg/mL. On a U-100 syringe, 1 mL is 100 IU of graduation, so 10 IU of graduation = 0.1 mL = 250 mcg, giving 20 draws per vial.

The most common trap: the volume of water never changes how much product is in the vial. Only the volume to draw changes. Our reconstitution calculator computes any other combination live.

Add the solvent slowly down the vial wall, then swirl gently. No vigorous shaking, no vortex — shear denatures peptides.

Storage

Lyophilized powder: -20 °C or below, protected from light and moisture; stable for years when unopened. After reconstitution: 2–8 °C, protected from light, with a reference shelf life of 28 days. For longer storage, frozen aliquots are preferable to repeated freeze-thaw cycles.

Common laboratory mistakes

• Treating tesamorelin, sermorelin and CJC-1295 as equivalent. 1-44 against 1-29, ≈ 5,136 Da against ≈ 3.4 kDa, acylation against position-2 substitution.
• Expecting a DAC-like duration. The trans-3-hexenoyl protects against DPP-4; it creates no albumin binding.
• Reading the clinical trial results across to the reagent. Those trials concern an approved medicine, distinct from this product.
• Using plain sterile water for a multi-draw vial. Without a preservative, the solution is unprotected once the stopper has been pierced several times.
• Vortexing the vial or repeatedly refreezing. Shear denatures the peptide and each freeze-thaw cycle degrades a fraction of it.