Growth Peptides
RESEARCH PURPOSES ONLY
All products sold by AbsoluteBioLab are strictly for laboratory and research purposes only. They are not intended for human consumption, diagnosis, treatment, prevention or cure of any disease. Not for veterinary use. By purchasing from us, you confirm you are a qualified researcher.
AbsoluteBioLab supplies high-purity, analytical-grade research peptides—including Ipamorelin, CJC-1295, and Tesamorelin—exclusively to UK laboratories and academic institutions. Every batch is HPLC-verified (≥99.0% purity) and dispatched domestically from our secure UK facility.
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Receptor Selectivity & Comparative Biochemistry
Growth hormone secretagogues (GHS) represent a structurally diverse class of research peptides that stimulate somatotroph cells of the anterior pituitary via discrete receptor pathways. Understanding the mechanistic distinctions between individual compounds is essential for designing rigorous in vitro and in vivo experimental protocols. The table below provides a comparative biochemical overview of the principal growth peptides available for laboratory research, highlighting receptor targets, molecular characteristics, and primary areas of scientific enquiry.
| Compound | Primary Receptor Target | Molecular Formula | Molecular Mass | Primary Research Focus |
|---|---|---|---|---|
| CJC-1295 (No DAC) | GHRH Receptor (GHRHR) | C152H252N44O42 | 3,367.9 Da | Pulsatile GH release kinetics; somatotroph sensitisation studies |
| Ipamorelin | Ghrelin Receptor (GHSR-1a) | C38H49N9O5 | 711.9 Da | Selective GH secretagogue activity; cortisol & prolactin independence research |
| Tesamorelin | GHRH Receptor (GHRHR) | C221H366N72O67S | 5,135.8 Da | Visceral adiposity modulation; IGF-1 axis regulation; metabolic phenotyping |
CJC-1295 (without Drug Affinity Complex, or "No DAC") is a truncated analogue of endogenous growth hormone-releasing hormone (GHRH 1–29), engineered to resist dipeptidyl peptidase IV (DPP-IV) cleavage through strategic amino acid substitutions at positions 2 and 8. Its half-life in aqueous solution is substantially shorter than the DAC-conjugated variant, making it the preferred tool for researchers modelling physiological, pulsatile GH secretion rather than sustained supraphysiological elevation.
Ipamorelin is a pentapeptide GH secretagogue that acts as a selective agonist at the growth hormone secretagogue receptor 1a (GHSR-1a), the canonical ghrelin receptor. Its selectivity profile is notably narrow: unlike earlier-generation GHS compounds such as GHRP-6 or GHRP-2, Ipamorelin does not significantly stimulate adrenocorticotropic hormone (ACTH), cortisol, or prolactin release at research-relevant concentrations, rendering it a cleaner pharmacological tool for isolating GH-axis effects in experimental models.
Tesamorelin is a synthetic analogue of full-length human GHRH (1–44) stabilised by the addition of a trans-3-hexenoic acid moiety at the N-terminus. This modification confers resistance to enzymatic degradation whilst preserving high-affinity binding to GHRHR. Research applications have centred on its capacity to modulate the GH/IGF-1 axis and its downstream effects on lipid metabolism, particularly visceral adipose tissue dynamics, making it a valuable compound in metabolic and endocrinological research programmes.
Reconstitution & Laboratory Handling Protocols
All growth peptides supplied by AbsoluteBioLab are presented as lyophilised (freeze-dried) powders, sealed under inert atmosphere within borosilicate glass vials. Correct reconstitution and storage are critical determinants of experimental reproducibility and peptide integrity. The following protocols reflect current best practice for handling GHRH analogues and GHSR agonists in a research laboratory setting.
Storage Prior to Reconstitution
Lyophilised vials should be stored at −20 °C in a desiccated environment, protected from light. Under these conditions, peptide integrity is maintained for a minimum of 24 months from the date of manufacture. Vials should be allowed to equilibrate to room temperature for a minimum of 15 minutes prior to opening, in order to prevent condensation-driven hydrolysis upon exposure to ambient humidity.
Reconstitution Procedure
For standard laboratory reconstitution, bacteriostatic water (0.9% benzyl alcohol in sterile water for injection) is the recommended diluent for stock solutions intended for short-term use. Sterile phosphate-buffered saline (PBS, pH 7.4) is appropriate for immediate single-use preparations. The following stepwise procedure is recommended:
- Wipe the vial septum with a 70% isopropyl alcohol swab and allow to dry for 30 seconds under laminar flow.
- Draw the required volume of diluent into a sterile syringe (typically 1–2 mL per 10 mg vial to yield a 5–10 mg/mL stock).
- Insert the needle at a 45-degree angle and direct the diluent stream gently against the inner glass wall — never inject directly onto the lyophilised cake, as this causes mechanical shearing of peptide secondary structure.
- Allow the vial to stand for 60–90 seconds, then gently swirl (do not vortex) until the powder is fully dissolved. The resulting solution should be clear and colourless; any turbidity or particulate matter indicates degradation or contamination.
- Aliquot into single-use volumes where possible to minimise freeze-thaw cycling. Reconstituted solutions in bacteriostatic water may be stored at 4 °C for up to 28 days; PBS solutions should be used within 72 hours.
pH & Buffer Considerations
CJC-1295 (No DAC) and Tesamorelin exhibit optimal solubility and conformational stability between pH 6.5 and 7.4. Ipamorelin, as a smaller pentapeptide, is more tolerant of mild pH variation but should nonetheless be reconstituted within this range. Avoid acidic diluents (pH < 5.0) as these may promote aspartate isomerisation at susceptible residues within the GHRH-derived sequences.
Adsorption & Vessel Selection
At low working concentrations (<100 µg/mL), non-specific adsorption to polypropylene and polystyrene surfaces can represent a significant source of experimental error. Researchers are advised to use low-binding microtubes (e.g., LoBind Eppendorf or equivalent) and to consider the addition of 0.1% bovine serum albumin (BSA) as a carrier protein in dilute working solutions, provided this is compatible with the downstream assay format.
Operational Decision: TFA Elimination via Double-Desalting Protocol In growth hormone secretagogue research, the presence of free t-butyl or other protecting group residues from solid-phase synthesis can cause receptor desensitisation. We chose to implement a double-desalting protocol using acetate-form exchange chromatography for CJC-1295 and Ipamorelin, ensuring a raw purity profile of ≥99.2% with zero residual trifluoroacetate (TFA) salts. Trifluoroacetate is routinely employed as a counter-ion during reversed-phase HPLC purification of synthetic peptides; however, its persistence in the final lyophilised product introduces a cytotoxic variable that confounds cell-based assay results and can artificially suppress receptor activation signals. By converting the TFA salt form to the acetate form through sequential ion-exchange chromatography steps, we eliminate this confounder entirely — a distinction that materially improves the reliability of GHSR-1a and GHRHR binding studies conducted with our material.
Combination Peptide Handling: CJC-1295 + Ipamorelin
The CJC-1295 + Ipamorelin 10 mg combination vial contains a co-lyophilised blend of both peptides in a defined molar ratio. When reconstituting combination vials, the same gentle swirling technique applies. Researchers should note that the two compounds act via distinct receptor populations (GHRHR and GHSR-1a respectively) and exhibit a well-characterised synergistic effect on GH pulse amplitude in pituitary cell models — a phenomenon that makes this combination particularly valuable for studying the convergent signalling architecture of the somatotroph axis.
Analytical Quality & Compliance Standards
AbsoluteBioLab operates under a rigorous quality framework designed to meet the demands of academic, pharmaceutical, and contract research organisations. Every batch of growth peptide manufactured and released for supply undergoes a multi-stage analytical verification process before it is assigned a batch number and made available for purchase.
HPLC Purity Verification
AbsoluteBioLab is a registered supplier of laboratory research
compounds in the United Kingdom
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