How we buy the sample.

Why blind-purchased samples are the baseline

Published third-party testing on peptide suppliers routinely uses vendor-provided "golden samples" — a vial the vendor picks and ships directly to the lab. Those results describe what a vendor can produce on a good day. They do not describe what arrives when an anonymous researcher places an order from the retail site. The gap between the two is where most of the supply-chain risk in this category lives.

Every assay Open Assay publishes is tagged either blind-purchase or vendor-provided, and only blind-purchase results feed the composite supplier rank. Vendor-provided results are published, attributed, and labeled — they are useful context, but they are not what we ultimately trust.

The purchase itself

A blind purchase, for our purposes, means every step of the transaction replicates what an anonymous retail customer would experience:

1. The order is placed through the vendor's public storefront — the same URL, the same product listing, the same cart flow a new visitor lands on. We do not use any wholesale, bulk, or researcher-portal pricing tier.
2. The shipping address is a generic residential address or a commercial mail receiving agency (CMRA) mailbox that is not associated with Open Assay on any public record. The name on the order is a purchasing alias we maintain specifically for this work; it is not "Open Assay" and it is not any staff member's real name.
3. Payment is made with a prepaid card or a business card that does not carry the Open Assay billing descriptor. Cards are rotated between purchases so a single BIN pattern does not identify us.
4. We do not email the vendor in advance. We do not ask about batch selection, lot numbers, or QC documentation before ordering. We do not claim academic affiliation for a discount. The purchase is the entire interaction.
5. When a vendor offers loyalty points, referral bonuses, or repeat-customer discounts, we accept whatever a default customer would be offered and no more. The buyer alias has no relationship with any vendor outside the transactions recorded in its purchase log.

Each order generates a purchase record with: order number, timestamp, vendor URL at time of order, product listing screenshot, payment instrument last four digits, shipping address used, and tracking number. That record is retained in an append-only internal log and referenced on the public assay page as a purchase ID. Researchers who want to audit a specific assay can request the purchase record by assay ID.

Receiving and inspection

When a package arrives, it goes through an intake workflow before anyone touches the contents:

• The outer packaging is photographed sealed, on all six sides, with a timestamped placard showing the assay ID. If the outer box is damaged, compromised, or shows evidence of opening in transit, the intake is halted and a new sample is ordered.
• The inner packaging — typically a vacuum-sealed mylar pouch or a padded envelope — is photographed before opening. Cold-chain indicators, if present, are photographed in place.
• Each vial is photographed against a neutral background with a scale reference. Labels, lot numbers, fill volumes, stoppers, and crimp seals are documented.
• The intake technician signs and dates a chain-of-custody form assigning the sample a barcode. From this point forward every movement of the vial is logged against that barcode.

Freezer storage before shipment to the lab

Lyophilized peptides are stable at room temperature for short periods but degrade measurably under repeated temperature cycling or prolonged ambient exposure. Between intake and handoff to the analytical lab, samples are stored in a dedicated −20 °C laboratory freezer that is not shared with household or food items. The freezer is on a monitored circuit with a continuous temperature logger; the log is retained and is attached to the assay's chain-of-custody record.

Reconstituted samples, when a test requires reconstitution before shipment, are held at −80 °C and aliquoted to minimize freeze-thaw cycles before analysis. Any sample that experiences a freezer excursion outside its documented range is either re-ordered or, if analyzed, has the excursion noted in the published COA. The analytical lab is informed of the storage history when the sample is transferred, and that history becomes part of the lab's intake record.

What would compromise a blind purchase

The integrity of this process depends on the vendor having no signal that a given order is destined for independent testing. A single slip — an email from a work address, a shipping address that resolves to our office in a public records search, a staff member placing an order under their own name — taints the blind status of that sample. If we discover mid-process that a purchase was not fully blind, the sample is either re-labeled as vendor-aware (and excluded from the composite rank) or discarded and re-ordered from a different alias. That determination is made before the sample leaves our custody.

When we re-purchase

A fresh blind purchase is initiated whenever: (a) a supplier formally disputes a failing result and we agree to re-test; (b) two or more independent community reports contradict our published result for the same product within thirty days; (c) a vendor changes manufacturer, upstream API source, or compounding facility; or (d) internal QA flags an anomaly in the original sample's chain of custody. Re-tests are ordered against the same public product listing the original came from, at our expense, and both results remain on the supplier page — the re-test does not overwrite the original.

See the lab chain-of-custody page for what happens after the sample leaves our freezer, and the editorial policy for the full re-test trigger list.