Selank from Selank Labs is a synthetic heptapeptide, supplied as a white lyophilized powder in 10 mg vials. Every lot is independently tested, and its results are published as a lot record with the certificate PDF.
Last updated
Specifications and current testing status in one place.
Selank is a synthetic seven-residue peptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its first four residues reproduce tuftsin (Thr-Lys-Pro-Arg), a short peptide fragment of the immunoglobulin G heavy chain, and the C-terminal Pro-Gly-Pro extension was added to make the sequence more resistant to peptidase cleavage. Three of its seven residues are proline, which gives the molecule a rigid, extended backbone, and its two basic residues (lysine and arginine) make it strongly cationic at neutral pH.
Selank Labs supplies Selank as a lyophilized powder in 10 mg vials. Each lot is tested by an independent laboratory for HPLC-UV purity, LC-MS identity and net content, and the full certificate is published here before the material is sold through Klow.bio.
Selank is linear, with a free N-terminal amine and a free C-terminal carboxylic acid. It has no cysteine, methionine or tryptophan, so it carries none of the residues most prone to oxidation. Lysine 2 and arginine 4 are the only charged side chains.
complete Selank 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 | Selank |
|---|---|
| Type | Synthetic heptapeptide |
| Molecular formula | C33H57N11O9 |
| Molecular weight | 751.87 g/mol (average) |
| Length | 7 residues |
| Sequence | TKPRPGP |
| N-terminus | Free amine (Thr1) |
| C-terminus | Free acid (Pro7) |
| CAS number | 129954-34-3 |
| Form | White lyophilized powder |
| Vial sizes | 10 mg |
| Purity specification | ≥95% (HPLC-UV) |
| Purity, current lots | 99.77% |
| 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: $29.99, 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 | KB55627 | 99.77% | Confirmed | 13.34 mg | Not tested | Lot KB55627 | Order 10 mg |
Ordering and shipping. Selank 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 Freedom Diagnostics, 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 separated sample enters a mass spectrometer via electrospray ionization, which gives the molecule one or more charges. The observed ions, near m/z 753 (1+) and 377 (2+), are matched against values calculated from Selank's molecular weight of 751.87.
Limits: confirms molecular weight, not amino-acid order.
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 LC-MS, with the laboratory’s reference numbers.
| Product | Selank 10 mg |
|---|---|
| Lot | KB55627 |
| Testing laboratory | Freedom Diagnostics |
| Received / reported | May 4, 2026 / May 5, 2026 |
| Purity (HPLC-UV) | 99.77% |
| Identity (LC-MS) | Confirmed |
| Net content | 13.34 mg |
| Endotoxin / PCR | Not tested / Not tested |
| Accession | 2605040415 |
HPLC-UV purity for each current lot.
Selank is a synthetic heptapeptide. Selank Labs supplies it as a white lyophilized powder in 10 mg vials, with an independent certificate of analysis for every lot.
Selank research material is Selank 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 C33H57N11O9 and the average molecular weight is 751.87 g/mol. The peptide has 7 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.
Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP): the tuftsin tetrapeptide followed by a Pro-Gly-Pro extension.
10 mg vials, sold through Klow.bio. The current lot measured 13.34 mg of peptide in the tested 10 mg vial.
Current Selank research material availability is provided through Klow.bio, the purchasing platform operated by Klow Labs: https://klow.bio/product/selank/ Lot records, testing information and certificates of analysis are published on selank.bio so they can be reviewed before purchasing.
Yes. Purchasing information and current availability for Selank research material are provided through Klow.bio: https://klow.bio/product/selank/
Yes. Every lot is tested by Freedom Diagnostics, an independent laboratory, for HPLC-UV purity, LC-MS identity and net content. The stated release specification is ≥95% HPLC-UV purity with identity confirmed by LC-MS. The current lot, KB55627, reported 99.77% purity.
Enter the lot number from your vial label at selank.bio/verify/ to see that lot's results. To confirm with the laboratory directly: Scan the Freedom Diagnostics QR code printed on the certificate, then search for klow.bio under the Company tab to view the laboratory record.
The current price is $29.99, 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 Selank 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 KB55627 tested at 99.77% purity with identity confirmed by LC-MS. Current purchasing is available through Klow.bio.