Writing a supplier corrective action request (SCAR) for a peptide nonconformance

A SCAR is not a damage claim

A damage or shortage claim is a commercial request: something arrived broken or missing, and you want a replacement, credit or refund. A SCAR asks a different question. It asks why the problem happened, whether other lots are affected, and what the supplier will change so it does not happen again.

The idea comes from quality systems. ICH Q10 says a company should have a system for corrective and preventive actions arising from complaints, product rejections, nonconformances, deviations and audits, using a structured investigation whose objective is the root cause. The effort and documentation should match the level of risk. [1] A small research lab is not bound by Q10, but borrowing its structure gives the supplier a clear request and gives you a record that holds up later.

In practice you often send both. File the claim first so you stay inside the supplier's window, then send the SCAR. Omni Peptides says claims must reach support within 48 hours of delivery and that later claims cannot be reviewed. [6] Peptides-EU asks for an email within 48 hours of delivery for damaged or missing parcels, and asks for photos and the order reference for incorrect or non-conforming items, without a stated deadline for those. [5]

Which problems justify a SCAR

Reserve the SCAR for problems where the cause could repeat or could affect other material. A single cracked vial in a crushed box is a claim. A certificate that names a different lot from the vial label, or a product sold as an acetate salt whose certificate reports trifluoroacetate, points to a system problem at the supplier.

GMP texts give a useful benchmark for when a certificate stops being trustworthy. ICH Q7 says a supplier's certificate of analysis can replace other tests only if the buyer has a system to evaluate suppliers, that the reliability of certificates should be checked at regular intervals, and that at least one identity test should be done on each batch. [2] The US drug CGMP rule likewise requires at least one identity test and validation of the supplier's results at appropriate intervals before a supplier's report can be relied on. [3] When your own check contradicts the certificate, that is the moment to ask for a SCAR.

• Salt form or counterion on the certificate differs from the product listing or quote.
• No certificate for the lot received, or a certificate for a different lot number.
• Independent mass result does not match the expected identity.
• Independent purity or content result falls outside the specification the supplier stated.
• The same type of problem on two or more orders, even if each was settled as a claim.
• The supplier is a reseller and cannot name the manufacturer. ICH Q7 expects a manufacturer to know the name and address of the original manufacturer when the supplier of a critical material is not the one who made it. [2]

The fields a SCAR should contain

Keep the request to one or two pages. The supplier should be able to see the problem, the requirement it breaks, the evidence and what you are asking for, with dates. The US CGMP rule on investigations is a good model for scope: an unexplained discrepancy must be investigated, the investigation must extend to other batches that may be affected, and a written record must include conclusions and follow-up. [4]

Template text you can adapt

Plain, factual language works best. Do not speculate about cause in the request; ask the supplier to investigate. Keep the claim and the SCAR in separate messages so the commercial remedy is not held up by the investigation.

• Subject: Supplier corrective action request SCAR-2026-003, order [number], lot [number].
• Problem: On [date] we received [quantity] units of [product, size], vial lot [x]. The certificate supplied for this order is for lot [y] and reports the [salt form] salt. Your product page and our quote dated [date] state [salt form].
• Evidence: Attached are photos of the vial labels, the certificate as received, the quote and our receiving record.
• Containment: Please tell us whether other stock of lot [x] or recent lots carry the same discrepancy, and hold or correct that stock.
• Root cause: Please investigate and tell us why the certificate and label differ.
• Corrective action: Please describe the change you will make and the first lot it applies to.
• Dates: Please acknowledge by [date], confirm containment by [date], and send root cause and planned action by [date].
• This request is separate from claim [reference] filed on [date] for replacement or refund.

Due dates and verification of effectiveness

No regulation sets due dates for a supplier's reply to a research lab, so set your own and write them down. A staged schedule is easier to hold a supplier to than a single deadline. The intervals below are our suggestion for a small lab, not a rule; adjust them to how much material is at stake. Omni Peptides says its support team typically responds within one business day, which makes a short acknowledgement window reasonable for that supplier. [6]

Verification is the step most often skipped. A promise is not evidence. ICH Q7 suggests full analysis at appropriate intervals compared with the certificate as the ongoing check on a supplier. [2] For a small lab, a practical version is to compare the certificate, label and invoice on the next lots received, and to commission an independent identity test on the first corrected lot if the original problem was identity or salt form.

A nonconformance log for a small lab

A SCAR only works if you can see patterns. Keep one log for every nonconformance, whether it became a claim, a SCAR, both or neither. ICH Q7's list of what a complaint record should hold is a good starting point: the nature of the problem including product name and batch, the date received, the initial action with date and person, and any follow-up action. [2]

The rows below are invented to show the format.

What you can and cannot expect

A research-use supplier has no obligation to run a corrective action process for you, and many small sellers will not have one. Peptides-EU, for example, says it will investigate and offer a replacement or refund where appropriate, and that opened or used products cannot be returned. [5] That is a remedy, not a root-cause commitment.

Decide in advance what you will do with each outcome. A full response with a credible cause and a verified fix supports keeping the supplier. A remedy without a cause may be acceptable for a one-off. No response, or the same problem again, is a reason to stop using the supplier for that material and to record why in your supplier file.