Lab methodology
From synthesis to your bench: how every Alphex batch gets tested.
Each compound passes a four-stage verification pipeline before it ever reaches a vial. Stage one is solid-phase peptide synthesis under controlled humidity to a known target molecular weight. Stage two is reverse-phase HPLC at 220nm against a reference standard - our acceptance threshold is >99.80% purity, well above the ~98% industry default.
Stage three is ESI-MS for identity confirmation. The mass spectrum must match the theoretical molecular weight within 1 Da. Stage four is Karl Fischer for water content and, where stability allows, LAL chromogenic assay for bacterial endotoxin.
The results from all four stages go onto the Certificate of Analysis that ships in the box with your order. Same batch number on the COA as on the vial label. Every order. Every batch.
For procurement
How to read a research peptide COA (and what to spot when it's fake).
Most COAs supplied with UK research peptides fail one of four checks. First: the batch number on the COA doesn't match the vial label. Second: the test date on the COA is more than 6 months old, suggesting the lab tested a precursor lot, not your specific batch.
Third: the COA shows no chromatogram, just a numeric purity claim. Without the trace, you can't verify the peak shape or related-substance shoulders. Fourth: the issuing lab isn't named, or the contact details are scrubbed.
An Alphex COA includes: batch number matching the vial label, test date within 30 days of synthesis, the full HPLC chromatogram at 220nm, identity confirmation by ESI-MS, Karl Fischer water content, and the issuing third-party lab's name and address.
Purity standards
Why >99.80% matters: the difference between research-grade and the rest.
The industry default for "research-grade" peptides is 98% purity. That sounds high until you look at the maths: a 98% sample is 2% something else. On a 10mg vial that is 200 micrograms of unknown impurities, related substances, deletion sequences, or oxidation products.
At >99.80% the impurity ceiling is 20 micrograms. The difference matters because related substances are often structurally close to the parent peptide and can confound assay readouts. If you are running a binding study, a 1.5% deletion sequence reads as the parent.
The cost difference between 98% and >99.80% comes down to longer HPLC purification runs and tighter cut criteria. We absorb that cost so your results are not contaminated by it.
Handling guide
Reconstitution, storage, and shelf life: protecting peptide integrity.
Lyophilised peptides are stable for 24 months at −20°C in their sealed vial. Once reconstituted with bacteriostatic water (0.9% benzyl alcohol), most peptides hold for 28 days at 2-8°C. Outside that window degradation accelerates.
Best practice: reconstitute only what you need, draw with a sterile needle each time, and never freeze-thaw an aqueous solution. Light-sensitive compounds (BPC-157, GHK-Cu) should be stored in their original vial or wrapped to exclude light.
If you suspect degradation, the chromatogram will show new peaks adjacent to the parent. We can re-test a returned sample by HPLC and replace at no cost if purity has fallen below our shipped threshold.
UK regulations
UK research peptide compliance: what you can and cannot do.
Research peptides supplied by Alphex are unlicensed substances. They are not authorised for human or veterinary use, and we do not supply them for that purpose. They are intended for use by qualified researchers in laboratory environments under appropriate institutional governance.
The Human Medicines Regulations 2012 and the Misuse of Drugs Act govern what can be supplied and to whom. Most research peptides we list are not controlled substances, but the legal framing is that they are unlicensed medicines: lawful to supply for research, unlawful to supply for human administration.
By ordering you confirm you are a qualified researcher, the materials are for laboratory research only, and you accept responsibility for compliant use within your jurisdiction and institution.
Procurement checklist
Choosing a UK research peptide supplier: the 12-point checklist.
1. Do they ship from UK domestic stock? 2. Do they supply a batch-matched COA with the order? 3. Is the COA from an independent third-party lab (named)? 4. Is the HPLC threshold stated and above industry default? 5. Does the chromatogram appear on the COA, not just a number?
6. Will they email you the in-stock batch's COA before you order? 7. Is the company UK-registered with a Companies House number? 8. Is the contact a named person, not a shared inbox? 9. Do they reply within working hours?
10. Vacuum-sealed packaging? 11. Tracked next-day courier? 12. Refund policy if purity falls short on independent verification?
Alphex meets all twelve. Most UK suppliers meet four to seven. Use the checklist before you order from anyone, including us.
