Looking for a Peptide Sciences Alternative? A Practical Comparison

What happened to Peptide Sciences

For years, Peptide Sciences was one of the most recognized names among U.S. suppliers of research peptides. Its catalog ran from single peptides such as BPC-157 and ipamorelin to multi-peptide blends, bioregulators, capsules and topical cosmetic peptides (archived catalog, February 2026).

In early March 2026, the company replaced its storefront with a short notice saying it had decided to voluntarily shut down operations and discontinue the sale of its research products. The notice is widely reported as dated March 6; the earliest copy in the Internet Archive was captured on March 8, 2026 (archived notice). It gave no reason for the closure, and we won't guess at one.

By April the notice had been expanded (archived April 15, 2026). It now says the company keeps all rights to its name and trademarks, and that any website, platform or person claiming to be affiliated with Peptide Sciences, to be its successor, or to sell its products is unauthorized. That is worth taking seriously: a site using the Peptide Sciences name or branding to sell to you today is not Peptide Sciences.

To be plain about our own position: Northbridge Research Labs is an independent U.S. company. We have no affiliation with Peptide Sciences, we did not acquire its inventory, and we do not sell its products. This page exists because many researchers who ordered there are now choosing a new supplier, and we think that choice should be made on evidence.

What researchers who relied on them need now

Losing a long-standing supplier in the middle of a project creates practical problems. Most labs need three things: material close enough to what they were using that ongoing work stays comparable, documentation that proves identity and purity for the specific lot they receive, and a supplier they can reach when something looks wrong. The rest of this page is organized around those three needs.

What to look for in a replacement vendor

These are the questions we would ask of any supplier, including us. None of them require taking a vendor's word for anything; each one can be checked before you place an order.

Peptide Sciences vs Northbridge Research Labs

For Peptide Sciences we list only what its own archived pages show; where we could not verify something, the cell says so. Since the company is closed, the useful question is less how it compared than whether your next supplier meets the standards above.

Peptide Sciences details from its archived product pages and closure notice. Northbridge details as of September 23, 2026; see shipping & returns and the COA library.

Peptide Sciences products and their Northbridge match

The left column lists compounds from Peptide Sciences' archived catalog, with the sizes it listed (February 2026; the capsule products from October 2025). The other columns show the closest Northbridge product, the sizes we carry, and whether a lot-specific certificate is published in our COA library yet. “Independently tested” means the batch was tested by an outside lab but its certificate has not been added to the public library.

Two of our catalog names are coded: RT-3 is our retatrutide-type research material and TZ-2 is our tirzepatide-type research material. Tirzepatide is the active ingredient in the approved drugs Mounjaro and Zepbound; the research material sold here is not those products and is not for human use.

Published lots and purities as listed in our COA library on September 23, 2026. New lots are added as batches are certified, so check the COA library for the lot printed on your vial.

Peptide Sciences carried a much wider range than we do. We don't currently offer equivalents for several of its lines, including GHRP-2, GHRP-6 and hexarelin, the 20mg bioregulator series, and its topical cosmetic peptides. If a compound you need isn't in the table, check the full catalog or ask us directly; we would rather tell you we don't carry something than suggest a substitute that isn't one.

How to switch suppliers without losing continuity

Changing suppliers mid-study is manageable if you treat it as a documented change rather than a like-for-like swap.

1. 1

   Match the compound, then the amount

   Start from the compound name, then compare milligrams per vial. Our sizes differ from the old ones for many products, so a lab that used a 5mg vial may now be working from a 10mg vial and should update its preparation records to match. For blends, compare the amount of each component, not the total on the label; two blends with the same name can be built in different ratios.

2. 2

   Confirm the format

   Our peptides are supplied as lyophilized powder in sealed vials, and a handful of products are capsules or solutions. If your work depended on a particular format, confirm it on the product page before ordering.

3. 3

   Look up the lot before you open the vial

   Find the lot number on the label and search it in our COA library. Check that the compound, size and lot on the certificate match the vial, and file a copy with your records. If your lot is not listed yet, email support@northbridgerl.com with the lot number.

4. 4

   Store it correctly on arrival

   Move lyophilized vials into storage as soon as the parcel arrives. Most of our peptide product pages list −20°C; keep vials sealed, dry and away from light until use, and follow the storage line on each product page. Tracking updates make it easier to be there when the parcel lands.

5. 5

   Note the change in your lab records

   A new supplier is a new variable. Record the supplier, lot number and certificate alongside any data generated with the new material, so results can be traced back if a question comes up later.

Frequently asked questions