The Figure Describes a Chromatogram, Not the Whole Vial
A purity statement of the “typically ≥99%” kind is among the most quoted lines in any peptide catalogue, and one of the easiest to misread. What it usually represents is an area-percentage: the main peak in a reversed-phase HPLC separation measured against the total integrated peak area, under a defined method and detection wavelength. It is a snapshot of chromatographic purity at the time of testing. It is not a promise that the vial in your hand will read the same number when you open it, and it is not a full description of what that vial contains.
The word “typically” is doing real work in that sentence. Research Sciences’ FAQs describe peptides as typically supplied at ≥99% purity (HPLC tested) and state that the exact purity is given on the CoA. Homepage wording such as “≥99% Verified Purity” and “UK Research Materials Over 99.1% Purity” is the shop’s published marketing language; treat it as a prompt to verify rather than as a substitute for the certificate attached to your specific batch. Reconfirm the current wording on the live site, and reconfirm the actual figure on the batch CoA before you build an assay plan around it.
Purity is only one axis of the specification
The About page describes full-spectrum testing as purity, identity, heavy-metal and endotoxin evaluation of submitted samples, with CoAs linked to supported products. The FAQs add that every compound includes a CoA (HPLC) covering purity and identity, that compounds are independently tested by HPLC, and that material is subject to final verification and quality checks in the UK before release. A ≥99% area figure speaks most directly to the first of those attributes. For a short, stability-conscious study window you also want the identity documentation and the contaminant screening in front of you, not assumed, because a high area-percentage on a chromatogram says nothing about whether the peak is the compound you ordered or how the lyophilised powder will behave once it is in solution.
The excipient and the mass balance
The FAQs note that all peptides contain trace amounts of mannitol, an excipient used to support lyophilisation, solubility and protection in storage. Mannitol does not appear as part of the peptide peak, but it is part of the mass in the vial. When you calculate a working concentration for an in-vitro assay, that is worth stating explicitly in your notes rather than silently treating vial mass as pure peptide. It is also worth remembering that the FAQ quick guide describes reconstituted peptides as less stable than the lyophilised starting material — the ≥99% figure belongs to the powder as tested, not to a solution left on the bench.
What to Confirm Before the Study Window Opens
Match the certificate to the vial in your hand
Vial labels use a reference format that combines the SKU code with an expiry date — for example BPC10-03/27 — which links to the corresponding CoA. Note that reference for every vial you plan to use and quote it whenever you contact the shop about documentation. Open the CoA and check the compound name, the purity figure stated for that batch, and the identity information, rather than relying on a category page headline. Where Janoshik is mentioned, the homepage simply lists “CoAs Janoshik Analytical Reports”; the practical step is to open and check the CoA that accompanies the specific batch you received.
Understand what an ITR does and does not confirm
The FAQs explain that restocked products may carry the same Internal Test Reference (ITR) as earlier stock. An ITR links to associated sample testing reports; it does not confirm that separate deliveries come from the same production lot or that they have had separate independent testing. Vial cap colours and other packaging may also vary, and cap colour is not an indicator of identity, analytical quality or manufacturing origin. In a short stability-conscious window, where you may be comparing week-one and week-four measurements, lot continuity and documentation continuity matter. Ask the question before the study starts, using the label reference.
Time the expiry against the window, then plan the handling
Lyophilised material should be stored at –20°C or below, sealed with desiccant and protected from moisture, heat and light, with repeated freeze–thaw cycles avoided. Reconstituted material is described as suitable for short-term laboratory use at 2–8°C. Allow vials to reach room temperature before opening, work in a clean environment, and remove only the amount required for the experiment. Buy enough individual vials that each is opened once for the window rather than repeatedly sampled; the shop states that it does not supply blended peptides and recommends buying peptides individually and combining only within a controlled experimental design. Keep reconstitution firmly inside an in-vitro workflow — diluent volume and target assay concentration — and note that the free reconstitution calculator is for laboratory research use only and must not be used for human or veterinary dosing.
Practical Checks on Supply, Documentation and Timing
Most of the confirmation work is a short email rather than a lengthy investigation: which CoA applies to this reference, what figure it states, what storage conditions are published for the item, and when dispatch is expected. On fulfilment, the site states that orders are dispatched the next working day via Royal Mail Tracked 24, which usually delivers the following working day as a Royal Mail estimate, with a tracking number issued after dispatch; delivery times are estimates and may vary in peak periods. The homepage “24hr UK Delivery” line is marketing wording rather than a guaranteed arrival, so build slack into your window. Because returns are not accepted once dispatched, with refunds limited to damage, incorrect supply or quality issues under the Refunds & Returns Policy, it is better to resolve documentation questions first. Payment is described as Pay-By-Bank / Open Banking through providers such as Wallid, regulated by the FCA; the shop states that it does not accept card payments for these research-use-only materials.
When you review the catalogue, start from the all-products listing and then open each individual product page for its batch documentation — you can Buy peptides only after you have matched the specification, storage instructions and expiry to your study design. Catalogue examples include Tesamorelin 5mg, MT-1 10mg, TB-500 5mg, Ipamorelin 5mg, CJC-1295 (No DAC) 5mg, GHK-Cu 50mg, BPC-157 10mg, a Storage Container, and 10ml Bacteriostatic Water / Mixing Water, with published specifications and storage guidance varying by listing.
Every material discussed here is supplied strictly for controlled laboratory and analytical research. These products are not for human or veterinary use, are not medicines, medical devices, injectables, treatments or food supplements, and are labelled “For Research Use Only – Not for Human Consumption” as the shop’s stated position in line with MHRA guidance. The purchaser is responsible for lawful use, safe handling, storage and disposal, and for compliance with relevant UK regulations including COSHH and laboratory safety standards. Treat a “typically ≥99%” headline as the beginning of your confirmation checklist, not the end of it — and verify it again, batch by batch, against the certificate that travels with the vial.
Kraków-born journalist now living on a remote Scottish island with spotty Wi-Fi but endless inspiration. Renata toggles between EU policy analysis, Gaelic folklore retellings, and reviews of retro point-and-click games. She distills her own lavender gin and photographs auroras with a homemade pinhole camera.