Who this checklist is for
This guide is written for researchers, laboratory managers and purchasing teams at UK universities, research institutes, contract research organisations and company R&D laboratories who buy synthetic peptides as research reagents. It is general information, not legal advice, and it applies to material bought for analytical and in-vitro laboratory work only.
1. Check how the supplier presents its products
Under UK law, a substance presented as having properties of preventing or treating disease in human beings is a medicinal product, whatever it is labelled as [1]. MHRA guidance explains that the agency looks at the claims made about a product, explicit and implicit, and at how it is presented through labelling, packaging, promotional literature, websites, social media and customer reviews [2].
For a buyer, the practical consequence is simple: a research-reagent supplier should describe products by identity – name, sequence, CAS number, molecular data – and by analytical results, not by what they might do in a person. Dosing tables, administration advice, before-and-after images or testimonials about effects are signs that material is being presented for human use rather than research. Our article on what research use only means in the UK covers the framework in more detail.
2. Ask for a lot-specific certificate of analysis
Peptide quality is normally specified in terms of identity, purity (related substances) and content, and a review of pharmacopoeial approaches proposed a consistent structure along those lines [3]. A research certificate of analysis is simpler, but it should still tie analytical results to one production lot.
- The lot number on the certificate should match the lot printed on the vial.
- Identity should be supported by mass spectrometry, with the observed mass compared with the theoretical value.
- Purity should be reported as an HPLC result, ideally with the chromatogram and method details.
- The certificate should say who performed the analysis and when.
A generic certificate that is not linked to a lot – or a single document reused across many batches – tells you little about the vial in front of you. Our guide to reading a peptide COA goes through each field.
3. Understand what the purity figure does and does not cover
Synthetic peptides carry characteristic related impurities – deletion and insertion sequences, diastereomers, incompletely deprotected sequences and degradation products – and a review of peptide impurities notes that these can influence experimental results [4]. That is why an HPLC purity figure matters.
HPLC purity is not the same as peptide content, however. Lyophilised peptides also contain water and counter-ions such as acetate or trifluoroacetate, which an HPLC area percentage does not capture [3][4]. If your experiment depends on an accurate molar concentration, ask whether net peptide content has been determined, or plan to measure it. The article on HPLC and mass spectrometry explains the difference.
4. Check storage, packing and delivery
Freeze-dried peptides are considerably more stable than peptides in solution, but residual moisture and storage temperature still govern how well the solid keeps [5], and chemical pathways such as deamidation, oxidation and hydrolysis proceed faster at higher temperatures [6]. Look for vials that are sealed, labelled with the lot number and a storage condition, and dispatched by a tracked service so that transit time is short and known.
On arrival, record the lot number and date of receipt and move vials to the stated storage condition. Our guide to storing lyophilised peptides summarises the degradation pathways and good laboratory practice.
5. Check the business behind the website
- Are company details, terms of sale and UK contact details published?
- Does the supplier ask for research-use declarations, and does it refuse questions about dosing or administration?
- Is delivery limited to the jurisdiction the supplier operates in?
- Are prices, delivery charges and dispatch times stated before you order?
- For institutional buyers: are quotations, purchase orders and invoice terms available?
How Britpep approaches each point
For transparency, this is how we handle the checklist above. Product pages give identity data and a referenced summary of the published literature, never human-use information. Each lot has a certificate of analysis reporting HPLC purity and mass-spectrometry identity, which can be looked up by the batch number on the label in our COA checker; our minimum purity specification is ≥98% by HPLC, with the measured value stated on each certificate. Orders are prepared to order – allow approximately seven days – and dispatched by Royal Mail Tracked 24 to UK addresses only.
Universities, institutes and companies can apply for a trade account for quotations and invoice terms, and our quality and testing page describes how lots are released. The full catalogue is on the shop page. All products are supplied strictly for laboratory research use only.
References
- The Human Medicines Regulations 2012, regulation 2: medicinal products. legislation.gov.uk. www.legislation.gov.uk/uksi/2012/1916/regulation/2
- Medicines and Healthcare products Regulatory Agency. Borderline products: how to tell if your product is a medicine. GOV.UK guidance. www.gov.uk/guidance/borderline-products-how-to-tell-if-your-product-is-a-medicine
- Vergote V, Burvenich C, Van de Wiele C et al.. Quality specifications for peptide drugs: a regulatory-pharmaceutical approach. J Pept Sci. 2009; 15:697-710. doi:10.1002/psc.1167. PubMed 19750489
- D'Hondt M, Bracke N, Taevernier L et al.. Related impurities in peptide medicines. J Pharm Biomed Anal. 2014; 101:2-30. doi:10.1016/j.jpba.2014.06.012. PubMed 25044089
- Wang W. Lyophilization and development of solid protein pharmaceuticals. Int J Pharm. 2000; 203:1-60. doi:10.1016/s0378-5173(00)00423-3. PubMed 10967427
- Manning MC, Chou DK, Murphy BM et al.. Stability of protein pharmaceuticals: an update. Pharm Res. 2010; 27:544-75. doi:10.1007/s11095-009-0045-6. PubMed 20143256
References were checked against PubMed and official UK sources at the time of writing. Summaries describe what each source reports; they are not claims about Britpep products.
