What a Lot Number Tells You, and How to Use Ours

Every compound we ship carries a lot number on its label. It is the one piece of information that connects the material in your hand to the batch it came from, to the testing done on that batch, and to your order with us. This post explains what a lot is, how we test each one, and how to use the number if you have a question.

What a lot is

A lot is a single production run of a compound. Peptide synthesis is a batch process, and two runs of the same compound can differ in purity and in the impurities present. That is normal chemistry rather than a fault, and it is why testing has to be done per lot to mean anything. A result for one lot says nothing about the next.

Where to find the number

The lot number is printed on the product label. When an order arrives, note the lot number of each item alongside your order number. Those two numbers are all we need to trace anything about the order.

How we test

Every lot we supply has been tested by a third-party laboratory. We also send each lot for our own independent re-test, by HPLC for purity and, where the laboratory offers it, mass spectrometry for identity, and post those reports by lot number on our Lab Reports page as they come back.

HPLC measures how much of the sample is the named compound. Mass spectrometry confirms that the compound is what the label says by matching its measured mass to the expected one. A report that shows one without the other is incomplete; our guide to reading a certificate of analysis explains both in detail and what else a complete report contains.

Matching a report to your compound

When you have a report in front of you, check four things against the label: the lot number is the same, the compound name is the same, the test date is consistent with when you bought it, and the report names the laboratory that ran the tests. If the lot numbers do not match, the report does not describe your material, however good its numbers look.

How we use lot numbers

We record which lot went out on each order. If you contact us about an order, we can see which lot it came from, and if a question arises about a lot, we can see which orders it went to.

If something does not match

Contact us with your order number, the lot number and a description of the issue. For a damaged, incorrect or missing item, tell us within 48 hours of delivery with photos of the package and the product label. If you believe a product does not match the identity, purity or quantity stated in the lab report for its lot, tell us within 30 days of delivery, with any analytical data you have. We may ask for the unused material back, at our expense, for evaluation. The Refund, Return & Cancellation Policy sets out the remedies.

What a lot number does not tell you

It tells you about the identity and purity of a specific batch. It says nothing about what the compound does, and neither do we. Researchers seeking information about a compound and the research being conducted with it should consult primary sources: government scientific and regulatory agencies, accredited institutions of higher education, and established research institutions.

All products are supplied for laboratory research use only, not for human or animal consumption. Purchasers must be 21 or older.