Where to buy research peptides in the US: the eight checks that separate a supplier from a reseller

A research peptide supplier sells synthetic peptides as laboratory reagents. The object it ships is specific: a glass vial with a rubber septum and an aluminum crimp cap, containing a stated mass of lyophilized powder, carrying a printed label with the compound name, the quantity in milligrams, a lot number and the words research use only. With each lot comes a certificate of analysis from an independent laboratory.

That is the whole product. A supplier describes it — composition, purity, storage, formats, documentation — and stops there. The pages you land on that describe anything else are not describing a reagent.

Research use only. Not for human or veterinary use.

Run every candidate through the same list. Most listings fail at the first line.

1. A verifiable, supplier-branded batch COA. An independent lab, a test number that resolves on the lab's site, and a photo of the supplier's own labeled vial. How to read one, field by field: how to read a peptide COA.
2. The lot number on the vial matches the certificate. A certificate for another lot covers nothing you hold.
3. Quantity stated in milligrams on the label. "1 vial" is not a quantity.
4. Tracked domestic delivery in 2–5 days. Long international transit is where parcels get heated, lost or held. OXpeptides ships tracked to the United States.
5. A product page that describes only the product. Composition, size, purity, storage, COA. A supplier whose pages say anything more is a supplier that can be shut down mid-order — and the order in transit at that moment is the one that pays for it.
6. A price at or above the market floor. Third-party testing costs a few hundred dollars per lot. A price well under everyone else's did not pay for it.
7. Traceable payment. Card or bank transfer with an invoice. A supplier that only accepts untraceable payment cannot be held to anything.
8. A written replacement policy for parcels that arrive damaged or never arrive.

The middle column is where the volume is — and where most of the complaints come from.

Every compound in the catalog ships the same way: lyophilized powder in a sealed, labeled glass vial, with a lot number, a batch certificate from Janoshik Analytical linked from the product page, and tracked delivery to the United States. Prices are listed per vial on each product page and are never repeated in these guides, so what you read there is what is in force today.

Sealed vials travel at ambient temperature; how they are kept afterwards is in lyophilized peptides: storage and shelf life.

Each guide follows the same plan: what the compound is, how it is supplied, what its certificate must show, how it is stored, and how to choose a supplier.

• GHK-Cu (copper peptide) — the copper tripeptide, blue-violet powder, 100 / 200 / 300 mg.
• AHK-Cu — the alanine copper tripeptide, 50 / 100 / 150 mg.
• BPC-157 — the 15-amino-acid pentadecapeptide.
• TB-500 — the synthetic fragment of thymosin beta-4.
• MOTS-c — the 16-amino-acid mitochondrial-encoded peptide.
• NAD+ — the coenzyme, as a lyophilized powder.
• Selank — the heptapeptide derived from tuftsin.
• Semax — the heptapeptide analog of ACTH(4-10).
• Bacteriostatic water — sterile water with 0.9 % benzyl alcohol.

Two things go wrong with peptide parcels: transit damage (a cracked vial, a crushed box) and a hold by a carrier or customs office. A supplier's answer to both should be in writing before you order.

• Damage: photograph the box and the vial as received, keep the packaging, contact the supplier the same day. A research supplier replaces the vial; the COA and lot are re-issued with the replacement.
• Hold or loss: tracked shipping exists so the position of the parcel is known. A supplier with domestic stock reships; one shipping from overseas often cannot.

The absence of a written policy is itself the answer.