Immune Support Research Peptides
Two compounds sit here and both carry a third-party purity result with the laboratory and the batch named. That isn’t true of every category on this site.
Only Thymosin Alpha-1 can be bought today. LL-37 has no price set, so it can’t be ordered whatever its stock label says, and we’d rather tell you here than let you find out at the checkout.
Neither is approved for human use in Canada. We publish no dosing, no protocols and no stacks.
What's here and what has been tested
| Compound | Identity | Purity | Laboratory | Batch |
|---|---|---|---|---|
| Thymosin Alpha-1 | Thymic peptide, also called thymalfasin | 98.95% | Medutest | WWB-TA10-3421 |
| LL-37 | Human cathelicidin, 37 residues. CAS 154947-66-7, 4,493 g/mol | 99.44% | Medutest | WWB-375-5496 |
Both figures came from HPLC. An HPLC purity result covers identity and purity of the material in the tested lot. It does not measure sterility, endotoxin or heavy metals, and it describes that lot rather than everything sharing a label. We hold each report and send it on request.
Thymosin Alpha-1 exists as an approved medicine in some countries
Worth knowing before anything else about this compound. Thymosin alpha-1, under the international name thymalfasin, is a licensed product in a number of countries. A 2020 review covers the literature on it.1
What we supply is not that licensed product. Research-grade material of the same peptide is made under different conditions, with no prescription and no approval, and clinical evidence for the medicine does not transfer to a vial bought online. We name the review so you know the literature exists and what it is about, not to borrow its conclusions.
There's also a naming trap here. Thymosin Alpha-1 and Thymalin are different compounds with different molecular weights and separate literatures, and they get confused. If a listing treats them as the same thing, that tells you how carefully it was written.
LL-37 is the human cathelicidin itself
LL-37 is a 37-residue peptide, the only cathelicidin found in humans, produced by neutrophil granules and epithelial cells. A 2000 paper in the Journal of Experimental Medicine identified FPRL1 as a receptor it uses to chemoattract neutrophils, monocytes and T cells.2
That's a receptor and cell-trafficking finding in laboratory work. It isn't a result in a person and we're not extending it into one.
Its purity result, 99.44%, is among the higher figures in our lab set. That says something about this batch's identity and purity and nothing at all about what the compound does.
Regulatory status in Canada
Health Canada regulates injectable peptides as drugs and has stated in writing that labelling one "for research use only" doesn't remove it from that regulation.3 Both compounds here are supplied for laboratory research use only, and neither is approved for human or veterinary use.
Thymosin alpha and LL-37 both appear on the seized-product list in Health Canada's notice.4 Where an approved medicine of the same molecule exists elsewhere, as it does for thymalfasin, selling an unapproved version attracts more scrutiny rather than less.
Buying immune peptides in Canada
Thymosin Alpha-1 ships in 5mg and 10mg, anywhere in Canada, and it's in stock. LL-37 is listed but has no price, so it can't currently be ordered.
Both are lyophilised powders and need bacteriostatic water, which we stock separately. Compare on price per milligram rather than price per vial. When you order, the batch reference travels on the packing slip, so the report we hold is the report for the vial you open.
The neighbouring set is healing and recovery research peptides, which is the other category here where every compound carries a certificate.
Browse the full range, or contact us with a compound name to ask for a certificate before you buy.
Common questions
What are immune peptides? A loose label for peptides that interact with immune signalling. Here it means one thymic peptide and one human antimicrobial peptide. It isn't a chemical class and it isn't a claim about immunity.
Which of these has a certificate of analysis? Both. Thymosin Alpha-1 at 98.95% and LL-37 at 99.44%, each with Medutest, each with the batch named.
Can I buy LL-37? Not at present. It has no price set. That's a listing gap rather than a stock problem, and it's one of five products on the site in the same position.
Is your Thymosin Alpha-1 the same as thymalfasin? Same molecule, different product. Thymalfasin is a licensed medicine in some countries, made under pharmaceutical conditions and prescribed. What we supply is research-grade material with no approval behind it.
What's the difference between Thymosin Alpha-1 and Thymalin? They're different compounds with different molecular weights and different published literatures, despite both being thymic peptides.
Are they safe? No safety profile has been established for either as supplied here, and a purity assay isn't a safety assessment. An HPLC result covers identity and purity in one lot. It doesn't measure sterility, endotoxin or heavy metals.
Are they legal in Canada? Health Canada regulates injectable peptides as drugs, and research use labelling doesn't change that. Nothing here is approved for use in a person, we won't supply dosing, and buying a vial doesn't make its use lawful.
How long does reconstituted material last? Much less time than sealed lyophilised powder. Reconstitution shortens the usable life considerably, which is why the vials ship as dry powder.
Sources
- Dominari A et al. "Thymosin alpha 1: A comprehensive review of the literature." World Journal of Virology, 2020. doi:10.5501/wjv.v9.i5.67. https://pubmed.ncbi.nlm.nih.gov/33362999/
- De Yang et al. "LL-37, the neutrophil granule- and epithelial cell-derived cathelicidin, utilizes formyl peptide receptor-like 1 (FPRL1) as a receptor to chemoattract human peripheral blood neutrophils, monocytes, and T cells." Journal of Experimental Medicine, 2000. doi:10.1084/jem.192.7.1069. https://pubmed.ncbi.nlm.nih.gov/11015447/
- Health Canada. "Think twice before injecting peptides bought online: unauthorized products can seriously harm your health." Advisory, 9 April 2026: "This type of labelling does not make these products legal or exempt from regulatory requirements." https://recalls-rappels.canada.ca/en/alert-recall/think-twice-injecting-peptides-bought-online-unauthorized-products-can-seriously-harm
- Health Canada. "Unauthorized injectable peptide drugs seized and sold by Canada Peptide may pose serious health risks." Thymosin alpha and LL-37 both appear on the seized-product list. https://recalls-rappels.canada.ca/en/alert-recall/unauthorized-injectable-peptide-drugs-seized-and-sold-canada-peptide-may-pose-serious
