Tesamorelin from Tesamorelin Labs is a synthetic 44-residue GHRH analog designed for activity at the growth hormone-releasing hormone receptor (GHRHR), supplied as a lyophilized powder in 10 mg vials. Every lot is independently tested, and its results are published as a lot record with the certificate PDF.
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Specifications and current testing status in one place.
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.
complete Tesamorelin specifications.
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. Lyophilized material absorbs moisture from the air, and absorbed moisture restarts the reactions that drying slows, so keep vials sealed until needed. Storage and stability guide.
| 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 |
Each vial size is listed with its current tested lot. Price: $59.99, with bundle pricing (2 vials save 5%; 3 or more vials save 10%). Current prices are always on klow.bio.
| 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 |
Ordering and shipping. Tesamorelin is sold through klow.bio, operated by Klow Labs LLC. Orders ship the next business day. Same-day cutoff is 4:00 PM CT, with overnight and 2-day options at checkout. See shipping and returns.
All testing is performed by ILS Laboratories, an independent laboratory, on every lot.
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.
Identity by HPLC retention-time match, with the laboratory’s reference numbers.
| 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 |
HPLC-UV purity for each current lot.
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.
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.
The amino acid sequence is the same; tesamorelin adds a trans-3-hexenoyl group to the N-terminal tyrosine.
ILS Laboratories confirms identity by HPLC retention-time comparison with a tesamorelin reference standard (HPLC-RTM). The method is listed on every lot record.
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.
Enter the lot number from your vial label at tesamorelin.bio/verify/ to see that lot's results. To confirm with the laboratory directly: 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.
The current price is $59.99, with bundle pricing (2 vials save 5%; 3 or more vials save 10%). Current pricing is always listed on Klow.bio.
Orders ship the next business day. Same-day cutoff is 4:00 PM CT, with overnight and 2-day options at checkout.
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.
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.