Common mistakes first-time peptide buyers make
Twenty mistakes from procurement to first reconstitution, each with the fix, and the short version at the end.
A first research peptide order involves a handful of decisions that are easy to get wrong and inconvenient to undo. This note collects the mistakes we see most often, from procurement through to the first reconstitution, with the fix for each. All Alphex products are for laboratory and in-vitro research only.
Buying
- Comparing prices per vial instead of per mg, landed. Add import VAT, courier fees and salt-form differences before concluding anything. See how pricing works.
- Accepting a COA after purchase. Ask for the current batch's certificate before ordering; if it cannot be produced, that is the finding. See requesting a COA.
- Reading a purity figure without the chromatogram. A number is a claim. See reading a chromatogram.
- Assuming "UK supplier" means UK stock. Ask where the parcel ships from. See spotting a drop-shipper.
- Not checking the compound is the compound. TB-500 is not thymosin beta-4; GHK-Cu is not GHK. Check mass and CAS. See CAS numbers.
- Buying one small vial for a long project. Batch consistency matters; buy the requirement together where you can. See vial sizes.
On arrival
- Opening a cold vial. Condensation onto the powder. Warm sealed to room temperature first.
- Not recording the batch number. It is the thread to the certificate and to any later question. See record keeping.
- Storing in the fridge door, or in a frost-free freezer without a box. See long-term storage.
- Panicking about an empty-looking vial. Milligrams of freeze-dried peptide can be an invisible film. See what lyophilised means.
Reconstitution and use
- Shaking or vortexing to dissolve. Foam denatures peptide. Slow addition down the wall, then patience. See the method.
- Using sterile water for a stock that will be sampled for weeks. Use bacteriostatic water, or accept a short life. See water comparison.
- Assuming nominal mass is peptide mass. See net versus gross.
- Not aliquoting. Repeated freeze-thaw and repeated punctures both cost material. See aliquoting.
- Diluting to working concentration in ordinary plastic and leaving it. Adsorption. See adsorption.
- Using a cloudy stock. Aggregated peptide is not at nominal concentration. See recognising degradation.
- Omitting the vehicle and scrambled controls. The result becomes uninterpretable. See controls and design.
- Treating GHK-Cu like an ordinary peptide. Light, chelators and phosphate all matter. See the GHK-Cu guide.
- Treating GLP-3 (RT) like a short peptide. Slow, gentle, buffered, low-binding. See lipidated peptides.
- Reading supplier summaries as evidence. Go to the primary literature. See reading the literature critically.
The short version
Get the certificate before you buy, check the mass matches the compound, keep it sealed and cold until the day you need it, add diluent slowly, aliquot, write the batch number on everything, and run the controls. That covers almost all of it.
Alphex research peptides are supplied for laboratory and in-vitro research by qualified researchers only. They are not authorised for human or veterinary use.
Research use only. Alphex products are supplied exclusively for laboratory and in-vitro research by qualified researchers. They are not authorised for human or veterinary use, and nothing in this note is advice on any such use.
Published 26 March 2026. Alphex reviews research notes when the testing method, the catalogue or UK guidance changes.