Description
PrymaLab · Research Use Only
Tesamorelin Peptide 10mg
One acyl group · and the only live human approval in the class
Tesamorelin peptide differs from the native hormone by one chemical group. It is the complete 44-residue growth hormone releasing hormone sequence with a trans-3-hexenoyl group attached at the amino terminus, and that single addition is the entire difference between a molecule cleared in minutes and one that holds an approved human formulation.
Specification Table
| Property | Value |
|---|---|
| Compound | Tesamorelin |
| Relationship to the native hormone | Full 44-residue growth hormone releasing hormone sequence, acylated at the amino terminus |
| Residue count | 44 |
| Modification | trans-3-hexenoyl group on the tyrosine at position 1 |
| Molecular weight, calculated | Approximately 5,135.9 g/mol, computed from residue masses plus the acyl group |
| CAS | 218949-48-5 |
| Receptor | GHRHR, the growth hormone releasing hormone receptor |
| What the acyl group does | Obstructs dipeptidyl peptidase-4 access to the amino terminus, slowing the dominant clearance route |
| Why the full length was retained | Unlike sermorelin, this molecule was not truncated, so residues 30 to 44 are present |
| Regulatory status | Holds an active approved human formulation in the United States, marketed as Egrifta |
| Relationship to that product | Material supplied here is not that product and is not manufactured to pharmaceutical standards |
| Appearance | White lyophilized powder |
| Purity | Per lot-specific certificate of analysis |
| Storage, lyophilized | 2-8°C short term, -20°C for extended storage, protected from light and moisture |
Why Is Tesamorelin Peptide Acylated?
One modification separates tesamorelin peptide from a molecule that would be cleared almost immediately, and the mechanism is physical rather than electronic.
Dipeptidyl peptidase-4 works by fitting the amino terminus of a substrate into an active site and cutting after position 2. Access to that terminus is the requirement.
On tesamorelin peptide the trans-3-hexenoyl group sits on the tyrosine at position 1, directly in the way. The enzyme cannot present the terminus correctly and the cleavage does not proceed at the rate it otherwise would.
That is a steric solution rather than a sequence one. The residues themselves are unchanged, which means receptor binding is unaffected, and the molecule is protected from the enzyme that would otherwise define its lifetime.
Compare that with the alternative approach used elsewhere in this class, which substitutes the position 2 residue for one the enzyme does not recognise. Both work and they do different things to the molecule.
A substitution changes the sequence and therefore has to be checked against receptor activity. An acyl group leaves the sequence intact and adds mass instead.
For verification the consequence is direct. An observed mass matching the unmodified 44-residue sequence means the acylation is absent, and the vial holds the native hormone rather than tesamorelin peptide.
That is the single most useful check available on this compound and it takes one line on a certificate.
Worth separating two things that get merged in summaries of this compound. Resistance to the enzyme and duration of measurable exposure are related and they are not the same quantity.
Blocking one clearance route slows disappearance by whatever share that route contributed. Other routes continue, including renal filtration and general proteolysis, and they set the floor.
Tesamorelin peptide is therefore longer-lived than the unmodified hormone by a factor the published work quantifies, rather than being resistant in any absolute sense.
Why Was the Full 44 Residues Kept?
Sermorelin demonstrated that residues 30 to 44 are not required for receptor activation, so their presence here invites a question.
The honest answer is that the two molecules were developed from different starting points rather than as a matched pair.
Truncation to 29 residues was a route to a cheaper and simpler article once the active region was known. Acylation of the full sequence was a route to a longer-lived one.
Nothing in the published record establishes that residues 30 to 44 contribute to activity in the acylated molecule either, so the length is best read as inherited rather than functional.
It does have a practical consequence. At 44 residues this is among the longer peptides in the catalogue, and synthesis difficulty scales with length.
Every coupling step carries a yield below one hundred percent, and across 44 steps small inefficiencies compound into a measurable population of deletion sequences.
A deletion on a 44-mer is roughly two percent of total mass, which is inside the error of a nominal-resolution instrument and outside the error of a high-resolution one.
So chain length here is not a neutral fact. It sets the analytical standard the certificate has to meet.
A related point about how the two molecules are usually presented side by side. They are not a controlled comparison, because they differ in two variables at once rather than one.
One is 29 residues and unmodified. The other is 44 residues and acylated. Any difference between them could come from either change, and no published work isolates the two.
What Does the Approval Status Mean Here?
Tesamorelin holds an active approved human formulation in the United States, which is unusual in this catalogue and worth stating precisely rather than loosely.
That approval belongs to a specific pharmaceutical product manufactured to pharmaceutical standards under a regulatory filing.
Tesamorelin peptide supplied here is not that product. It is research-grade material supplied under research-use-only terms, and the approval attaches to the filing rather than to the molecule in the abstract.
The distinction matters because an approved molecule is sometimes presented as though the approval travelled with any material bearing the same name. It does not.
What the approval does provide is an unusually good published record. The pivotal work was conducted to regulatory standard and reported in the peer-reviewed literature, which is not true of most compounds in this range.
A researcher can therefore read primary trial data for this compound rather than inferring from animal models, which is a real advantage over most of the catalogue.
That literature used the approved formulation. Applying its figures to research material assumes an equivalence that has not been demonstrated for any particular lot.
Reading the trial and then verifying the vial is the sequence that makes sense here, and the certificate is what closes the gap.
What Should a Tesamorelin Certificate Show?
Seven fields, and three are specific to an acylated peptide of this length.
Whether the observed mass includes the acyl group. This is the first question and it distinguishes the analogue from the unmodified native sequence.
The instrument resolution used for that determination, because a single deletion on a 44-mer sits within nominal-mass error.
Purity by chromatography with the gradient and detection wavelength stated, and the chromatogram rather than a summary percentage, since deletion sequences resolve by retention more reliably than by mass.
The sequence written out, which distinguishes tesamorelin peptide from the 29-residue fragment sold under a different name.
Counterion identity and net peptide content. For a peptide this size the proportional correction is smaller than for a short compound and it is still material.
Lot number and synthesis date, tying every preceding figure to the material that will ship.
Whether the acylation site was confirmed rather than assumed, since an acyl group on the wrong residue produces the correct mass and the wrong molecule.
That last point is the one most often skipped, and mass spectrometry alone cannot answer it without fragmentation data.
What Does the Acyl Group Cost?
Every modification buys something and pays for it somewhere, and the accounting on this one is rarely stated.
It adds a synthesis step. The acylation is performed after chain assembly and it has to go to completion, because an incompletely acylated batch contains a mixture of the analogue and the native hormone.
Those two species differ by roughly ninety-six daltons on a five-thousand dalton molecule, which is under two percent and therefore inside nominal-mass error.
So the purification burden rises alongside the analytical one.
It adds a site-confirmation requirement. Tesamorelin peptide carries the acyl group on the position 1 tyrosine, and acylation chemistry can also modify lysine side chains, of which this sequence has several.
A batch acylated on the wrong nitrogen has exactly the correct total mass and does not behave the same way at the receptor.
Distinguishing them needs fragmentation data rather than a single mass measurement, which most certificates do not include and most buyers do not ask for.
It raises surface activity. A lipid group on a peptide increases adsorption to container walls and increases the tendency to accumulate at the air-liquid interface, where aggregation starts.
That is a handling cost rather than a chemistry one, and it is manageable with low-binding consumables and gentle reconstitution.
None of this argues against the modification. Tesamorelin peptide exists because the trade was worth making, and a laboratory buying it should know which parts of the trade land on the certificate and which land on the bench.
How Should Concentration Be Determined?
Weighing is the obvious method and it is the least reliable one available for this compound, which is worth saying plainly.
A lyophilised cake carries water, counterion and residual solvent alongside peptide. A balance reports all four and cannot separate them, so a gravimetric concentration is an upper bound rather than a measurement.
Ultraviolet absorbance at 280 nanometres is the practical alternative and it works here because the sequence carries tyrosine.
The method needs an extinction coefficient, which is computed from the count of tyrosine, tryptophan and cystine in the sequence rather than measured. For a peptide with tyrosine and no tryptophan the value is dominated by the tyrosine count and is straightforward to calculate.
That calculation assumes the sequence is what the label says. If the vial holds the unacylated native hormone, the aromatic content is unchanged and the absorbance reading will be identical, so this method confirms quantity rather than identity.
Amino acid analysis is the reference method and it answers both questions at once, since it reports the molar ratio of each residue after complete hydrolysis.
It is destructive, it takes a day, and it is the only routine technique that independently establishes how much peptide is present without trusting the certificate.
For most work the sensible sequence is to accept the net peptide content figure, confirm it once by absorbance, and reserve amino acid analysis for a first lot from a new supplier.
Whichever route is used, tesamorelin peptide should have its concentration basis written into the record alongside the number, because a concentration without a method is not reproducible.
Two laboratories reporting the same figure by different methods are not necessarily reporting the same thing.
How Should the Vial Be Handled?
Storage requirements for tesamorelin peptide match the rest of the GHRH group, with one addition that follows from the acyl group.
Lyophilized powder is stable sealed against moisture at 2 to 8 degrees Celsius for short periods and at minus 20 for longer, protected from light.
Let the vial reach ambient temperature before the seal is broken. Cold glass pulls atmospheric moisture onto the cake, and that water becomes part of every subsequent calculation.
Reconstitute slowly down the vial wall and swirl rather than shake, because agitation at the air-liquid interface drives aggregation and this molecule is long enough for that to matter.
The lipid group raises surface activity relative to an unmodified peptide, which makes the aggregation caution more relevant here than for sermorelin.
Aliquot on first reconstitution. Repeated freeze-thaw is the most avoidable cause of loss and it cannot be undone once aggregation starts.
Use low-binding consumables at working concentrations, since adsorption removes a measurable fraction of dilute peptide from small volumes.
Record the lot, net peptide content, diluent volume and date of first reconstitution, which together allow the preparation to be reproduced.
Published Literature
Selected references on the native hormone and on the pivotal published work for this compound.
- Falutz J, Allas S, Blot K, Potvin D, Kotler D, Somero M, et al. New England Journal of Medicine. 2007;357(23):2359-2370. DOI: 10.1056/NEJMoa072375
- Stanley TL, Falutz J, Marsolais C, Morin J, Soulban G, Mamputu JC, et al. Clinical Infectious Diseases. 2012;54(11):1642-1651. DOI: 10.1093/cid/cis251
- Guillemin R, Brazeau P, Bohlen P, Esch F, Ling N, Wehrenberg WB. Science. 1982;218(4572):585-587. DOI: 10.1126/science.6812220
- Pace CN, Vajdos F, Fee L, Grimsley G, Gray T. Protein Science. 1995;4(11):2411-2423. DOI: 10.1002/pro.5560041120
Frequently Asked Questions
What is tesamorelin peptide?
The complete 44-residue growth hormone releasing hormone sequence carrying a trans-3-hexenoyl group at the amino terminus. It binds GHRHR, the same receptor as the native hormone.
What does the acyl group do?
It obstructs dipeptidyl peptidase-4 access to the amino terminus. The enzyme cannot present the terminus correctly, so the cleavage that would otherwise define the molecule lifetime does not proceed at the same rate.
Is that different from substituting position 2?
Yes. A substitution changes the sequence and has to be rechecked against receptor activity. An acyl group leaves the sequence intact and adds mass, which is a steric solution rather than a sequence one.
Why is it 44 residues when sermorelin is 29?
The two were developed from different starting points rather than as a matched pair. Truncation gave a cheaper article, acylation gave a longer-lived one, and nothing establishes that residues 30 to 44 contribute to activity here either.
Does the length affect verification?
Substantially. At 44 residues a single deletion is roughly two percent of total mass, which sits inside the error of a nominal-resolution instrument, so high-resolution mass spectrometry is the standard here.
Does tesamorelin hold an approval?
Yes. It holds an active approved human formulation in the United States marketed as Egrifta. That approval attaches to a specific pharmaceutical product manufactured under a regulatory filing.
Does that approval apply to this material?
No. Material supplied here is research-grade peptide under research-use-only terms and is not that product. Approval attaches to the filing rather than to the molecule in the abstract.
What advantage does the approval give a researcher?
An unusually good published record. The pivotal work was conducted to regulatory standard and reported in peer-reviewed journals, which is not true of most compounds in this catalogue.
What is the single most useful certificate check?
Whether the observed mass includes the acyl group. A mass matching the unmodified 44-residue sequence means the acylation is absent and the vial holds the native hormone rather than the analogue.
Can mass spectrometry confirm the acylation site?
Not on its own. An acyl group on the wrong residue gives the correct total mass and the wrong molecule, so site confirmation needs fragmentation data rather than a single mass figure.
Why does aggregation matter more here?
The lipid group raises surface activity relative to an unmodified peptide, so agitation at the air-liquid interface drives aggregation more readily. Swirl rather than shake and aliquot on first reconstitution.
How should the vial be stored?
Sealed against moisture, refrigerated for short periods and frozen at minus 20 for longer, with light excluded. Allow the vial to reach ambient temperature before the seal is broken.
Compliance Statement
Tesamorelin peptide is sold exclusively for laboratory research use. It is not a drug, food, or cosmetic product, and it is not a dietary product of any kind. It is not approved by the FDA or any comparable authority for human or veterinary use, tesamorelin holds an active approved human formulation in the United States but material supplied here is not that product and is not manufactured to pharmaceutical standards, published trial data was generated using the approved formulation rather than research-grade material, and no equivalence between the two has been demonstrated for any particular lot. This product is not intended to diagnose, treat, cure, or prevent any disease. It must not be given to humans or animals. Purchase is restricted to qualified researchers and institutions operating within applicable laws. All handling is the responsibility of the purchasing laboratory.
Other formats of Tesamorelin
Tesamorelin is also stocked as Tesamorelin 10mg preloaded 3ml pen. Each listing states its own quantity and concentration, and the pen and vial comparison explains what changes between formats.
18 reviews for Tesamorelin 10mg