A Tesamorelin research supplier built around testing and transparency.
Tesamorelin Labs is a dedicated Tesamorelin research supplier with a controlled sourcing and quality-assurance program. Research material is sourced through our qualified manufacturing supply chain and subjected to analytical testing and lot-level documentation before release. Current availability is provided through Klow.bio.
For laboratory research use only. Tesamorelin Labs does not provide medical advice or usage guidance.
The essential facts about Tesamorelin and Tesamorelin Labs. Every figure on this page comes from the published certificates of analysis or the product specification.
Last updated
Tesamorelin is a synthetic analog of growth hormone-releasing hormone (GHRH). It carries the complete 44-residue GHRH sequence, ending in a C-terminal amide, with one change: a trans-3-hexenoyl group is attached to the N-terminal tyrosine. That six-carbon acyl cap protects the N-terminus from dipeptidyl peptidase-4, the enzyme that otherwise removes the first two residues of GHRH. Tesamorelin is designed as an agonist of the GHRH receptor (GHRHR), a class B G protein-coupled receptor.
Tesamorelin Labs supplies it as a lyophilized powder in 10 mg vials. Each lot is tested by ILS Laboratories for HPLC purity, identity against a reference standard and net content, with a fentanyl screen, and the certificate is published here before the material is sold through Klow.bio.
At 44 residues and over 5,100 g/mol, tesamorelin is one of the larger linear peptides in research catalogues. It contains a single methionine (Met27), the residue most likely to oxidize, and no cysteine, so there are no disulfide bonds. The N-terminal trans-3-hexenoyl group and the C-terminal amide are its only modifications.
Tesamorelin is supplied as a lyophilized powder in 10 mg vials. It is sold through klow.bio, operated by Klow Labs LLC, where current pricing, bundle discounts and shipping options are listed. Orders ship the next business day. Same-day cutoff is 4:00 PM CT, with overnight and 2-day options at checkout.
| Product | Tesamorelin |
|---|---|
| Type | Synthetic 44-residue GHRH analog |
| Molecular formula | C221H366N72O67S |
| Molecular weight | 5135.86 g/mol (average) |
| Length | 44 residues |
| Sequence | YADAIFTNSYRKVLGQLSARKLLQDIMSRQQGESNQERGARARL |
| N-terminus | trans-3-Hexenoyl-Tyr1 |
| C-terminus | Amide (Leu44-NH2) |
| CAS number | 218949-48-5 |
| Receptor design | Growth hormone-releasing hormone receptor (GHRHR) |
| Form | Lyophilized powder |
| Vial sizes | 10 mg |
| Purity specification | ≥95% (HPLC-UV) |
| Purity, current lots | 99.54% |
| Storage | Store sealed, dry and protected from light at the temperature stated on the vial label. Allow a cold vial to reach room temperature before opening. |
| Designation | Research use only |
Tesamorelin research material from Tesamorelin Labs is available through klow.bio, the online store of Tesamorelin Labs’ parent company, Klow Labs LLC. Product information, lot results and the certificate of analysis for every lot are published here on tesamorelin.bio.
Tesamorelin comes in 10 mg vials, currently priced at $59.99, with bundle pricing (2 vials save 5%; 3 or more vials save 10%). Orders ship the next business day. Same-day cutoff is 4:00 PM CT, with overnight and 2-day options at checkout.
| Vial size | Current lot | Purity (HPLC-UV) | Identity | Net content | Endotoxin | Certificate | Order |
|---|---|---|---|---|---|---|---|
| 10 mg | KB-77284 | 99.54% | Confirmed | 10.45 mg | Not tested | Lot KB-77284 | Order 10 mg |
Tesamorelin Labs publishes lot-specific analytical documentation for its Tesamorelin research material. Each item below is published for every lot and can be checked against the laboratory record.
Every lot is tested by ILS Laboratories, an independent analytical laboratory. Published results come from the laboratory's certificate, not in-house testing.
Every lot's certificate is published as a PDF, with the chromatogram behind the purity figure, alongside a readable lot record.
The laboratory runs the sample and a reference standard of the named compound under the same HPLC conditions; identity is confirmed when the main peak elutes at the reference standard’s retention time. The method is named on every lot record, so it is clear what the result does and does not establish.
Current lots test at 99.54% by HPLC-UV, well above the ≥95% release specification, with net content measured on every lot.
Every certificate carries the laboratory's QR code. You can confirm results directly with the lab instead of taking our copy on trust.
Lots without endotoxin or microbial testing say "Not tested". Each certificate page explains what the tests do and don't establish.
Tesamorelin Labs is built around five things: a dedicated Tesamorelin focus, a controlled supply chain, independent analytical testing, lot-level transparency and current availability. Each reason below links to the evidence. See the full quality and supply-chain process.
One compound, not a catalog of unrelated products.
Material sourced through qualified manufacturing partners.
≥95% HPLC-UV purity with identity confirmed by HPLC retention-time match against a reference standard.
Every lot tested by ILS Laboratories, with the results shown.
A public record for every lot, with dates and laboratory reference numbers.
The laboratory certificate for each lot.
Look up any lot by the number on the vial.
Clear about what the material is for and what we don't provide.
Live stock, pricing and checkout.
The questions worth asking any supplier of Tesamorelin research material, why each one matters, and how Tesamorelin Labs answers them.
| What to check | Why it matters | Tesamorelin Labs |
|---|---|---|
| Independent third-party testing | Results produced by the seller can't be checked independently. | ✓ Every lot tested by ILS Laboratories |
| Lot-specific certificates | A generic certificate may not describe the vial you receive. | ✓ Each COA tied to the lot number on the vial label |
| Chromatogram available | A purity figure without the trace behind it can't be evaluated. | ✓ In the certificate PDF for every lot |
| Separate identity test | HPLC purity shows how much of the sample is the main peak, not which compound the peak is. | ✓ HPLC retention-time match on every lot |
| Measured net content | Confirms how much peptide is actually in the vial. | ✓ Measured on every lot; current lots at or above label size |
| Contaminant screening | Checks for a specific contaminant the laboratory screens for. | ✓ Fentanyl screen on every current lot: not detected |
| Verifiable with the lab | Prevents altered or reused certificates. | ✓ Lab QR code on every certificate |
| Named company and contact | Accountability requires a real business you can reach. | ✓ Klow Labs LLC, Chicago; (708) 262-7687 |
Each row is one tested lot. Figures are copied from the laboratory certificate; open a lot to see its full record and download the certificate PDF.
| Lot | Vial size | Net content | Purity (HPLC-UV) | Identity (HPLC-RTM) | Endotoxin (LAL) | Microbial (PCR) | Reported | COA |
|---|---|---|---|---|---|---|---|---|
| KB-77284 | 10 mg | 10.45 mg | 99.54% | Confirmed | Not tested | Not tested | View lot KB-77284 |
Testing laboratory: ILS Laboratories. Release specification: purity ≥95% by HPLC-UV with identity confirmed by HPLC retention-time match against a reference standard. Results apply only to the lot listed. Certificates list the testing client as Klow.bio / Klow Labs LLC, the company that operates Tesamorelin Labs.
The current lot tested at 99.54% by HPLC-UV. Lot-to-lot comparisons will appear here as further lots are tested.
Measured net content was at or above the labeled vial size for every current lot: 10.45 mg in a 10 mg vial.
A purity figure says the sample is homogeneous; it does not say which compound the main peak is. That is answered by a separate identity test: HPLC retention-time comparison with a reference standard (HPLC-RTM).
The laboratory runs the sample and a reference standard of the named compound under the same HPLC conditions; identity is confirmed when the main peak elutes at the reference standard’s retention time. A retention-time match is consistent with the named compound under the laboratory’s method. It is not a mass measurement, which is why the method is always named next to the result.
| Product | Tesamorelin 10 mg |
|---|---|
| Lot | KB-77284 |
| Testing laboratory | ILS Laboratories |
| Received / reported | Sep 9, 2026 / Sep 11, 2026 |
| Purity (HPLC-UV) | 99.54% |
| Identity (HPLC-RTM) | Confirmed |
| Net content | 10.45 mg |
| Fentanyl | Not detected |
| Endotoxin / PCR | Not tested / Not tested |
| Certificate number | COA-2026-ST4K1C |
| Lab access code | M24R3BUV |
Four methods appear on Tesamorelin certificates. Each answers a different question, and none answers every question on its own, which is why they are used together.
Reversed-phase high-performance liquid chromatography separates the sample's components by hydrophobicity, and a UV detector records each as a peak. Purity is the main peak's area as a percentage of all detected peak area.
Limits: does not identify the peak, and impurities that co-elute or absorb weakly in UV can be under-counted. More on HPLC
The laboratory runs the sample and a reference standard of Tesamorelin under the same chromatographic conditions. Identity is reported as confirmed when the sample’s main peak elutes at the reference standard’s retention time.
Limits: a retention-time match is consistent with the named compound but is not a mass or structure measurement; compounds with similar retention can co-elute. More on HPLC
The laboratory screens each lot by immunoassay at the cutoff printed on the certificate. Current lots are reported as not detected.
Limits: a negative result means below the cutoff for the sample tested; an immunoassay screens for its target only.
The laboratory quantifies the main compound in the tested vial against a standard. It is reported in milligrams next to the labeled vial size.
Limits: measured on the vial tested; other vials from the same lot are expected to be similar but are not individually measured.
You shouldn't have to take a supplier's word for its results. Here's how to check a Tesamorelin certificate yourself.
Technical articles on Tesamorelin, peptide analysis and laboratory documentation. Sources are limited to NIH and FDA publications. Start at the Tesamorelin research hub.
Retention time, peaks, area normalization and every lot's HPLC result.
DocumentationEvery section of a Tesamorelin COA, red flags, and what it does and doesn't prove.
Analytical methodsPurity vs. content vs. net content, impurity sources and comparing claims.
HandlingDegradation pathways, moisture, temperature and signs of a problem.
Tesamorelin is a synthetic 44-residue GHRH analog designed for activity at the growth hormone-releasing hormone receptor (GHRHR). Tesamorelin Labs supplies it as a lyophilized powder in 10 mg vials, with an independent certificate of analysis for every lot.
Tesamorelin research material is Tesamorelin supplied for laboratory research, sold by lot, with each lot's identity, purity and net content documented by an independent laboratory in a published certificate of analysis.
The molecular formula is C221H366N72O67S and the average molecular weight is 5135.86 g/mol. The peptide has 44 residues.
Tesamorelin is analyzed with complementary methods: HPLC-UV for purity, HPLC-RTM for identity, a quantitative measurement for net content, and, where listed, LAL endotoxin and PCR microbial testing. Results are published per lot at tesamorelin.bio/coa/.
Every lot is tested by ILS Laboratories, an independent third-party analytical laboratory. Tesamorelin Labs does not test its own material for published certificates.
Current lots report HPLC-UV purity 99.54%, against a stated release specification of ≥95%. The most recent result is 99.54% for lot KB-77284.
A Tesamorelin certificate of analysis is the testing laboratory's report for one lot: the lot number, test dates, methods and results for purity, identity and net content. Tesamorelin Labs publishes every lot's COA as a readable page at tesamorelin.bio/coa/.
Find the lot number printed on your vial label and enter it at tesamorelin.bio/verify/, or open that lot in the COA archive at tesamorelin.bio/coa/.
Go to portal.ils-lab.com (or scan the QR code on the certificate) and enter the lot's verification access code, listed on its lot page, to view the laboratory's own copy of the certificate.
Current Tesamorelin research material availability is provided through Klow.bio, the purchasing platform operated by Klow Labs: https://klow.bio/product/tesamorelin/ Lot records, testing information and certificates of analysis are published on tesamorelin.bio so they can be reviewed before purchasing.
Yes. Purchasing information and current availability for Tesamorelin research material are provided through Klow.bio: https://klow.bio/product/tesamorelin/
Yes. Every lot is tested by ILS Laboratories, an independent laboratory, for HPLC-UV purity, HPLC-RTM identity and net content. The stated release specification is ≥95% HPLC-UV purity with identity confirmed by HPLC retention-time match against a reference standard. The current lot, KB-77284, reported 99.54% purity.
Tesamorelin Labs is a dedicated Tesamorelin research supplier with a controlled sourcing and quality-assurance program. Research material is sourced through our qualified manufacturing supply chain and subjected to analytical testing and lot-level documentation before release.
Tesamorelin Labs operates tesamorelin.bio and supplies one research material, Tesamorelin, with the analytical record behind every lot. Tesamorelin Labs is operated by Klow Labs LLC, a Chicago company that also operates klow.bio, where Tesamorelin is sold.
Our job is narrow on purpose: supply a well-characterized research material and publish the evidence for what is in each vial. We do not provide medical advice, protocols or usage guidance.
10 mg vials. Current lot KB-77284 tested at 99.54% purity with identity confirmed by HPLC retention-time match against a reference standard. Current purchasing is available through Klow.bio.