Semaglutide 5mg

✓ Two laboratories — Janoshik #101805 and Testides ARUA-SEMA-5-061826

Assayed by Janoshik Analytical, report #101805, analysis conducted January 2026: 99.247% purity by HPLC, measured peptide content 6.05 mg against a 5 mg nominal fill.

Confirmed by Testides, Toronto, report ARUA-SEMA-5-061826 on lot SEMA5-0626-01, reported 7 October 2026: 99.15% purity by HPLC-UV at 214 nm with measured peptide content 5.33 mg against the same 5 mg label. Purity agrees; content differs by 0.72 mg, and both figures are published.

All lot results · How to read a peptide COA

This lot has now been assayed by two laboratories, and they do not agree on how much peptide is in the vial: 6.05 mg at Janoshik, 5.33 mg at Testides against the same 5 mg label. Both are above label and the purity figures are within a tenth of a percent, so the lot is not in question — but the 0.72 mg spread is real and we publish it.

Semaglutide is a 31-residue analogue of human glucagon-like peptide-1 carrying two amino-acid substitutions and a C18 fatty diacid on Lys26, supplied here as 5 mg of lyophilised powder for laboratory research.

The interesting thing about semaglutide is not what it does at the receptor — native GLP-1 does that — but what had to be engineered so it could keep doing it. Endogenous GLP-1 has a circulating half-life of roughly one to two minutes. It is cleaved by dipeptidyl peptidase-4 at the His⁷-Ala⁸ bond within seconds of secretion, and what survives DPP-4 is cleared renally almost as fast. Semaglutide is the result of solving both problems at once, and each modification maps onto one of them.

There are exactly three changes from the GLP-1(7-37) backbone. Ala⁸ is replaced by α-aminoisobutyric acid (Aib), a quaternary, non-proteinogenic residue whose gem-dimethyl substitution sterically blocks the DPP-4 cleavage site. Lys³⁴ is replaced by arginine — not for pharmacology, but so that the acylation chemistry has only one lysine to find, making Lys²⁶ the sole and unambiguous attachment point. And Lys²⁶ carries a C18 octadecanedioic acid — a fatty diacid, not a monoacid — tethered through a γ-glutamic acid residue followed by two oligoethylene-glycol (OEG/AEEA) spacer units. The free distal carboxylate on that diacid and the length of the hydrophilic spacer together tune albumin affinity: bound to albumin, the molecule is too large to filter at the glomerulus and is shielded from proteolysis, and it is released slowly enough to maintain receptor occupancy for days. Lau and colleagues, who published the discovery programme, measured the resulting plasma half-life at 46.1 hours in mini-pigs after intravenous administration, and the Canadian product monograph for the licensed drug gives roughly one week in humans.

That trade is visible in the binding data and is worth stating because vendor copy usually inverts it. Semaglutide is less potent at the GLP-1 receptor than liraglutide — Lau reported an affinity of 0.38 ± 0.06 nM, about threefold weaker — and it is nonetheless far more effective in vivo, because duration of exposure, not peak affinity, is the limiting variable. Anyone using this vial as a reference agonist in a short in-vitro assay is measuring the property semaglutide was allowed to give up, not the one it was designed for.

The 5 mg vial is the entry size. At $44.99 it works out to $9.00 per nominal milligram, against $7.00/mg for the 10 mg vial — a 22% premium for the smaller format. On measured content the gap narrows a little — this lot assayed at 6.05 mg at Janoshik and 5.33 mg at Testides, so $7.44 or $8.44 per measured milligram depending on which report you take — but the direction does not change. The case for the 5 mg vial is not price per milligram. It is that a smaller fill is reconstituted, aliquoted and consumed in fewer handling cycles, which matters for a molecule whose stability liabilities are handling-driven rather than intrinsic.

Semaglutide has an unusually deep human evidence base for a compound sold as a research reagent — the STEP and SUSTAIN programmes plus the SELECT cardiovascular outcome trial, tens of thousands of randomised participants — and that depth cuts both ways. It means the pharmacology is well characterised. It also means the failures, the withdrawal data and the adverse-event signals are documented in detail rather than absent, and we publish those next to the positive findings below. This vial is supplied strictly as a laboratory reagent. We give no dosing, route, schedule or administration guidance of any kind; the clinical data exist because licensed products were developed from the same molecule under regulatory oversight, not because anything on this page is a medicine.

For laboratory and research use only. Not for human consumption, veterinary use, or therapeutic application. Not approved by Health Canada. We do not provide preparation, dilution or administration guidance for any compound we sell.