How research peptide pricing works

Research peptide prices vary by a factor of five or more for the same nominal product, and the cheapest listing is rarely the cheapest peptide. Understanding what goes into the price of a vial (synthesis, purification to specification, testing, vialling, holding stock, and the supplier's accountability) makes it possible to compare like with like and to see where a low price is a saving and where it is a warning. This note explains the cost structure and gives a method for comparing suppliers on a per-mg basis. All Alphex products are for laboratory and in-vitro research only.

What goes into the price of a vial

• Synthesis. Cost scales with length and difficulty: a 5-residue peptide is cheap per mg; a 39-residue lipidated peptide with unnatural residues is not. Bulk synthesis is much cheaper per mg than small lots.
• Purification to specification. Reaching 98% needs one preparative HPLC pass; 99+% often needs a second, or a slower gradient, and each pass discards material in the shoulders. The cost of the last percentage point rises steeply with length. See 98% versus 99+%.
• Independent testing. HPLC and MS per batch at an accredited laboratory is a fixed cost per batch, so it is proportionally larger for small batches and for suppliers who test every batch rather than one a year. See third-party versus in-house testing.
• Vialling. Filling, lyophilisation, stoppering under vacuum, crimping and labelling are largely fixed per vial, which is why per-mg cost falls with vial size. See vial sizes and per-mg cost.
• Holding stock. Freezer inventory in the UK ties up capital and carries the risk of ageing stock; drop-shipping avoids both, which is why drop-shippers can be cheaper and why the saving is not free. See how to spot a drop-shipper.
• Accountability. A UK company with a replacement guarantee, a real address and UK legal exposure carries costs a website does not.
• Margin, VAT and shipping. UK prices include 20% VAT; foreign prices do not, and import VAT arrives later. See UK versus US versus China suppliers.

Comparing per mg, properly

1. Convert every price to £ per mg of nominal peptide: price divided by vial mass.
2. Add import VAT (20% of goods plus shipping), courier fees and exchange margin for foreign suppliers.
3. Adjust for salt form if stated: a TFA salt has lower net peptide content than an acetate salt of the same peptide. See acetate versus TFA.
4. Adjust for purity specification: 98% versus 99+% is a real difference in what you receive.
5. Add the cost of independent testing if the certificate is manufacturer QC only, and the cost of a failed experiment if you skip it.
6. Then compare.

On that arithmetic, a UK-stocked, independently tested acetate salt at 99+% is frequently the cheapest usable peptide, even where its invoice price per vial is higher.

What a suspiciously low price usually means

One or more of: TFA salt, 95-98% specification, manufacturer QC only, drop-shipped, generic COA, or a smaller net content than the label suggests. Occasionally it means a genuine bulk buy passed on; ask the questions in questions to ask before ordering and the difference becomes clear.

How Alphex prices

Prices include VAT and are per vial, with per-mg cost falling with size (the specification table and product page show sizes; the product page shows live prices). What the price includes: acetate salt, 99+% HPLC at 220 nm, ESI-MS identity, independent laboratory testing of every batch, batch-numbered vials, UK stock, same-day dispatch before 2pm Monday to Friday, tracked next-day delivery, and the purity guarantee. Repeat and multi-vial terms are in bulk and repeat orders.

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 24 April 2026. Alphex reviews research notes when the testing method, the catalogue or UK guidance changes.

Alphex Research Team

Alphex Limited, UK research peptide supplier

The Alphex research team writes and maintains these notes for UK laboratories buying research peptides. Every batch Alphex lists is verified by reverse-phase HPLC with a batch-matched Certificate of Analysis. Content covers laboratory and in-vitro research only.