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🇬🇧 Dispatched from the UK
Vials assayed to > 99% HPLC purity
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Hello Peptides
Buying 3 min read

Buying research peptides in the UK

Peptides for sale online vary enormously in quality, and the label tells you very little. Five checks tell you most of what you need to know about a supplier.

HP Written by the Hello Peptides lab team · Updated October 2026

Why the supplier matters more than the price

A research peptide is only useful if it is what the label says, at the purity the label says. A vial that is 85% product and 15% synthesis by-products will not announce itself. It just produces results nobody can repeat. The cost of a bad batch is the experiment, not the vial.

Five things to check

  1. 01
    A certificate for the batch, not the productA certificate of analysis should carry the batch number printed on your vial. A single undated PDF used for every order is a sample, not a test result.
  2. 02
    Independent testingThird-party tested means a laboratory other than the seller ran the assay. Look for the laboratory name on the certificate.
  3. 03
    Both HPLC and mass spectrometryHPLC gives the purity figure. Mass spectrometry confirms the molecule is the right one. You want both.
  4. 04
    A UK dispatch addressParcels sent from overseas spend days in transit and customs at whatever temperature the season provides. UK stock shipped cold arrives the next day.
  5. 05
    No medical claimsA supplier promising results in people is selling an unlicensed medicine, and is unlikely to be careful about anything else.

Our guide to reading a batch certificate explains each line of a certificate of analysis, and the COA library holds ours.

Red flags

  • One certificate shown for every batch, or a certificate with no batch number or date.
  • No laboratory named on the certificate.
  • No batch number printed on the vial itself.
  • Dosing charts, treatment claims or before-and-after pictures anywhere on the site.
  • No contact address, and no answer to a direct question about testing.
  • A price far below everyone else for the same stated purity.

Any one of these is a reason to ask questions. Several together are a reason to buy elsewhere.

Vials, pens and what pre-mixed means

Most suppliers sell lyophilised vials: a freeze-dried powder that has to be reconstituted before use. Everything in our range is supplied pre-mixed instead, in solution and ready to use. The trade-off is storage. A solution must stay refrigerated and must not be frozen. See peptide pens and vials for how the formats compare.

LyophilisedPre-mixed
Arrives asFreeze-dried powderSolution
PreparationReconstitution with bacteriostatic waterNone
ConcentrationSet by the water you addFixed, and stated on the label
StorageStable unopened, refrigerated once mixedRefrigerated throughout, never frozen

What an order from us includes

  • Compounds assayed to over 99% purity by an independent laboratory before the batch is released
  • A batch-specific certificate of analysis in the box and in the COA library
  • Cold-chain packing with a temperature indicator, dispatched from the UK
  • Same-day dispatch on weekday orders placed before 2pm, and free UK shipping over £100

The full range is in the shop. Laboratories and clinics ordering at volume can apply for a wholesale account.

Research peptides can be lawfully bought in the UK for laboratory research. They are not medicines and cannot be sold for human use. Are peptides legal in the UK? sets out where the line sits.

Research use onlyProducts are supplied for laboratory research and are not for human or animal consumption, diagnosis or treatment. Questions about a batch? Contact the lab with the batch number.
Keep reading All guides →
Quality Reading a batch certificate What the HPLC trace, mass spec and purity figure actually tell you. 5 min read Regulation Are peptides legal in the UK? What UK law says about buying and selling research peptides, and where the line sits. 4 min read Delivery Cold chain and unboxing What arrives in the box, the temperature indicator and what to do if it tripped. 3 min read
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