Tesamorelin Spray

What Is Tesamorelin?

Tesamorelin is a 44-residue synthetic peptide corresponding to the complete sequence of human growth hormone-releasing hormone, carrying a trans-3-hexenoyl group acylated onto its N-terminus. Its molecular formula is C₂₂₁H₃₆₆N₇₂O₆₇S and its average molecular weight is 5135.86 g/mol as the free base. It appears in the literature under the development code TH9507.

The modification is worth understanding precisely, because it is frequently described incorrectly. Tesamorelin carries no substituted residues. Native GHRH is cleaved rapidly by dipeptidyl peptidase at the Tyr1-Ala2 bond, and tesamorelin’s answer to that is to cap the N-terminus rather than to swap an amino acid — which is what distinguishes it structurally from the CJC-1295 compounds, whose stability comes from four engineered substitutions on a shorter backbone.

That design produces a clean arithmetic identity check. Native human GHRH(1-44) has an average mass near 5039.73 g/mol. The trans-3-hexenoyl group contributes C₆H₈O, or 96.13 g/mol. The sum is 5135.86 — the published mass of tesamorelin. A spectrum consistent with roughly 5136 rather than roughly 5040 is direct evidence that the acylation is present and intact.

At the receptor, tesamorelin binds the growth hormone-releasing hormone receptor on pituitary somatotrophs, a class B G-protein-coupled receptor, with growth hormone release and hepatic IGF-1 production downstream. Its reported half-life is 26 to 38 minutes. That figure is worth carrying, because half-life values quoted for CJC-1295 with DAC — a molecule engineered for covalent albumin conjugation and multi-day persistence — are sometimes transferred to tesamorelin. They do not apply. A single acyl cap is not albumin binding.

Tesamorelin Spray for Laboratory Research

A spray-format material arrives as a prepared solution rather than a dry powder. There is no reconstitution step, the concentration is set by the manufacturer rather than chosen at the bench, and the solvent system, any excipients and the stability profile of a peptide already in solution are properties of that specific preparation rather than of tesamorelin as a compound.

For this molecule there is a documented reason to take that distinction seriously. The licensed pharmaceutical formulations of tesamorelin are supplied as lyophilised material with defined reconstitution schedules — the earlier F4 formulation reconstituted daily, the F8 formulation approved in 2025 requiring weekly reconstitution and less than half the administration volume. Those schedules were set by the manufacturer of a product made under a biologics licence. They say something about how tesamorelin is handled in solution in a pharmaceutical setting, and they are a reasonable prompt for asking a supplier what the equivalent basis is for any prepared-solution research material.

No published study of intranasal or other mucosal tesamorelin administration was identified in preparing this page. Route-comparison literature does exist for smaller peptides in this area — sermorelin and GHRP-6 both have published non-injected human data — but tesamorelin at 5136 g/mol is a substantially larger molecule, and that literature does not extend to it. Researchers should not assume otherwise from the presence of a spray format.

Product documentation and lot-specific analytical information should be reviewed before a material enters an experimental workflow.

Research Context

Tesamorelin appears in research contexts including:

• Growth hormone-releasing hormone receptor (GHRHR) pharmacology
• GHRH-axis signalling and somatotroph response
• Structure-function studies of N-terminally acylated peptides
• Comparative pharmacology across GHRH analogues of differing backbone length
• Peptidase resistance and enzymatic stability research
• Analytical characterisation and identity confirmation of large synthetic peptides
• Formulation and stability research on multi-kilodalton peptides
• Endocrine research involving GH and IGF-1 axis regulation

Published clinical findings concerning tesamorelin were generated with a licensed pharmaceutical product administered subcutaneously in defined patient populations under trial protocols. They do not establish that this research material is safe or effective for any use, and they are not transferable to a different formulation or route.

Key Features

• Tesamorelin research material supplied as a prepared spray solution
• Complete 44-residue human GHRH sequence with no substituted amino acids
• Single trans-3-hexenoyl modification at the N-terminus
• Molecular weight 5135.86 g/mol; formula C₂₂₁H₃₆₆N₇₂O₆₇S
• 96.13 Da mass separation from unmodified GHRH(1-44) as an identity check
• Approximately 1,778 Da heavier than sermorelin; approximately 1,489 Da heavier than CJC-1295 with DAC
• Acts at the GHRH receptor, not the growth hormone secretagogue receptor
• Supplied ready in solution — no reconstitution step
• Intended exclusively for research and laboratory purposes; not for human or veterinary consumption

Why Choose Tesamorelin Spray from Helix Bio?

The useful thing a supplier can offer on a compound like this is a way to check what the material actually is.

Tesamorelin is well separated by mass from everything it is likely to be confused with. At 5135.86 g/mol it sits roughly 1,778 Da above sermorelin, roughly 1,489 Da above CJC-1295 with DAC, and roughly 96 Da above unmodified GHRH(1-44). The last of those is the one that matters most, because it is the smallest gap and the one that confirms the defining modification is present rather than absent. A certificate of analysis reporting a molecular ion consistent with 5136 is doing real identity work; one reporting only a purity percentage is not, since a highly pure sample of the wrong peptide still reports as pure.

Two things to check rather than assume. Tesamorelin has two CAS registry numbers in circulation — 218949-48-5 for the free base and 901758-09-6 for the salt — and vendor listings cite them interchangeably even though they refer to different substances. And research material is normally supplied as the acetate while 5135.86 is the free-base mass, so net peptide content needs its basis stated to be interpretable. For a solution product, concentration carries the same ambiguity.

Helix Bio states that its research peptide catalogue uses independent HPLC testing for purity assessment and mass spectrometry for molecular identity confirmation, and that batch-specific Certificates of Analysis are available. For Tesamorelin Spray specifically, the applicable lot documentation is what establishes the analytical result.

Who This Product Is For

Tesamorelin Spray is intended for qualified users working in legitimate laboratory or scientific research environments, including:

• Academic endocrinology and neuroendocrinology laboratories
• Receptor pharmacology and GPCR signalling research groups
• Biotechnology and pharmaceutical research organisations
• Contract research organisations
• Analytical laboratories developing identity and purity methods for large synthetic peptides
• Peptide formulation and stability research groups
• Educational research institutions

The product is not intended for personal experimentation, self-administration, human consumption, veterinary use, or medical treatment.

GHRH Receptor Research. Tesamorelin is a full-length GHRH analogue, which makes it useful in receptor work where the complete native sequence is wanted rather than a truncated one. GHRHR is a class B G-protein-coupled receptor, and questions about how backbone length affects receptor engagement are answerable by comparing full-length and fragment-based analogues directly.

Tesamorelin Compared With Sermorelin. Both act at GHRHR and both derive from human GHRH, and there the similarity ends. Sermorelin is the unmodified 29-residue N-terminal fragment with a C-terminal amide, at 3357.93 g/mol. Tesamorelin is the complete 44-residue hormone with an N-terminal acyl cap, at 5135.86. Roughly 1,778 Da separates them. Neither is established as superior; they are different molecules with different evidence bases and, as set out in the compliance section, materially different regulatory positions.

Tesamorelin Compared With the CJC-1295 Compounds. Both are described as GHRH analogues and both are built on different principles. The CJC-1295 compounds use the 29-residue fragment with four engineered amino acid substitutions; the DAC form adds a linker for covalent albumin conjugation. Tesamorelin substitutes nothing and conjugates to nothing — its entire modification is one acyl group on an otherwise native sequence. The pharmacokinetic consequence is the point worth carrying: tesamorelin’s 26 to 38 minute half-life belongs to a short-acting molecule, and persistence figures reported for albumin-conjugated compounds are properties of that conjugation rather than of GHRH analogues generally.

Receptor-Class Separation. Ipamorelin, GHRP-2 and GHRP-6 act at the growth hormone secretagogue receptor, the ghrelin receptor, not at GHRHR. Convergence on a shared endpoint is not shared mechanism, and the two classes are not experimental substitutes for one another.

Analytical and Formulation Research. At 5136 g/mol tesamorelin sits well above the size range where most research peptides fall, which makes it relevant to method development for identity confirmation, purity determination and stability assessment of larger synthetic peptides. The sequence contains residues with recognised chemical liabilities in peptide chemistry generally, including methionine and asparagine, which is one reason formulation and analytical characterisation are treated seriously for this molecule.

Clinical Research — and its boundary. Tesamorelin has an unusually substantial clinical literature for a compound sold as a research material: randomised trials reported in the New England Journal of Medicine (2007), the Journal of Clinical Endocrinology & Metabolism (2010), JAMA (2014) and The Lancet HIV (2019), plus a study of cognition in older adults published in Archives of Neurology (2012).

Every one of those studies used a licensed pharmaceutical product, administered subcutaneously, in a defined patient population, under a trial protocol. They establish what that product did under those conditions. They establish nothing about a research-grade material, a different formulation, a different route of administration, or any use outside the studied populations, and they should not be cited as though they did.

Purity & Quality Standards

For a 44-residue peptide the analytical questions differ from those for a short one. Longer sequences give synthesis more opportunities to go wrong, and the characteristic impurities — deletion sequences missing one residue, truncated chains, incompletely deprotected material — sit closer in mass to the target than the impurities of a hexapeptide do. Chromatographic purity and mass confirmation answer different questions here, and both are needed.

The identity check that carries most information is the acyl cap. Unmodified GHRH(1-44) sits near 5039.73 g/mol and tesamorelin near 5135.86 — a 96.13 Da separation. A mass consistent with the lower figure would indicate material lacking the modification that defines the compound.

Helix Bio states that its peptide materials are subjected to independent HPLC testing for purity and mass spectrometry for molecular identity, and that batch-specific Certificates of Analysis are available. For a specific Tesamorelin Spray lot, the applicable COA and product documentation carry the actual analytical results.

Researchers should assess, where applicable:

• Peptide identity, confirmed by molecular ion consistent with 5136 g/mol
• Confirmation that the mass reflects the acylated compound rather than unmodified GHRH(1-44)
• Reported purity and the analytical method used
• Net peptide content, and whether reported on a free-base or salt basis
• Which CAS number the documentation references, and therefore which substance was characterised
• Salt form of the material
• Concentration of the prepared solution and the basis on which it is expressed
• Lot or batch number and test date
• Storage requirements specific to the formulation
• Expiration or retest information, when provided

No certification, regulatory approval, or quality claim should be inferred unless explicitly documented by the manufacturer or the relevant regulatory authority.

Storage & Handling

Storage and handling requirements should be determined from the current Tesamorelin Spray product documentation and lot-specific instructions.

General laboratory considerations include:

• Follow the storage conditions supplied with the product.
• Protect the material from inappropriate temperature, light, and environmental exposure.
• Keep the container properly closed when not in use within an approved research workflow.
• Avoid unnecessary temperature cycling.
• Maintain appropriate laboratory labelling and inventory records.
• Follow institutional procedures for handling research peptides.
• Do not use material beyond the stated storage period or applicable retest date without appropriate laboratory qualification.
• Consult the current COA and product documentation for product-specific requirements.

Two transfers to avoid. Storage conditions published for lyophilised tesamorelin do not apply to a prepared solution — a peptide already in solution has a different stability profile, and container, closure and solvent all contribute. And handling conditions for the licensed pharmaceutical product do not apply either; that product is manufactured, formulated and labelled under a biologics licence, and its conditions describe it rather than this material.

Shipping & Packaging

Helix Bio’s website describes research materials as being supplied to laboratories and institutions in the United States and describes tracked shipping and cold-chain handling within its fulfilment process.

Because shipping conditions, packaging specifications, availability and delivery requirements may change, researchers should review the current Helix Bio shipping information and product listing before ordering.

Product packaging should remain appropriately labelled and handled as research material after delivery. Researchers are responsible for following applicable institutional, federal, state and local requirements governing research materials.

Important Disclaimer

Tesamorelin Spray is sold by Helix Bio for research and laboratory purposes only. It is not intended for human or veterinary consumption, self-administration, diagnosis, treatment, cure, mitigation, or prevention of any disease or medical condition.

Tesamorelin’s regulatory position requires a precise statement rather than a simple one, because both a flat “approved” and a flat “not approved” would mislead.

Tesamorelin is the active ingredient of a licensed prescription biological product in the United States, approved in 2010 and supplied for subcutaneous injection. On 23 March 2020, under the transition provision of the Biologics Price Competition and Innovation Act, approved applications for biological products were deemed to be licences under section 351 of the Public Health Service Act, and tesamorelin’s application transitioned accordingly.

That licence attaches to a specific product, manufactured under a biologics licence to defined standards, in a defined formulation, for a defined route and population. It attaches to nothing else. A research-grade material sharing the same active ingredient is not covered by it, has not been evaluated by FDA, and carries no approval of any kind.

One consequence follows directly and is worth stating because it distinguishes tesamorelin from every neighbouring compound. FDA’s guidance to compounders states that biological products transitioning under that provision are not eligible for the compounding exemptions in sections 503A and 503B of the FD&C Act. Tesamorelin therefore falls outside the bulk drug substances framework entirely, rather than occupying a category within it. This reflects its regulatory classification, not a safety determination.

This product is not a dietary supplement, consumer wellness product, or medical treatment. Researchers are responsible for determining whether a material is appropriate for their intended experimental application and for complying with applicable institutional and regulatory requirements.