How do I compare BCH and SWB on lead time to South Africa?

The particulars: BCH · SWB · South Africa.

Both of these get recommended confidently by different people, which suggests neither is obviously right.

My constraints are cost, measurement resolution and how much handling I am prepared to do — in roughly that order.

What is the actual trade-off, and does it matter at the scale I am working at?

The short version: same compound, same laboratory, same method, ideally same week — otherwise you are comparing laboratories rather than suppliers.

Publish the method with the result. A comparison without the laboratory named and the submission dates given is not reproducible by anyone.

In practice, content is the more discriminating measurement than purity for supplier comparison, because purity clusters tightly among competent suppliers and content does not.

The ratings on this site are a community opinion average on a ten-point scale and are not reconciled with any other community's figures.

The caveat is that a comparison is a snapshot of the lots compared, and lots change.

Use a fixed documentation checklist rather than an impression.

Answering this needs the axis. A supplier that is best on paperwork and a supplier that is best on price are both correct answers to different questions.

Compare documentation on a fixed checklist rather than by impression: lot specificity, method section, chromatogram availability, quantified content, water and counter-ion figures, and whether the code is on the vial.

To compare properly: order the same compound at the same nominal strength from each supplier, submit all samples to the same laboratory in the same submission if possible, and ask for the same test set on each.

Price per milligram of measured peptide, not per milligram of label claim.

This is the question where methodology matters more than the conclusion.

Cost per milligram of actual peptide is the honest price comparison, which means dividing by measured content rather than by label claim.

Content assay results across the published datasets vary considerably more between suppliers than purity does, which makes content the more discriminating axis.

Name the laboratory and the dates or the comparison cannot be reproduced.

The relevant detail is that ratings on this site are ours alone and are deliberately not reconciled with anyone else's.

Sample size matters. One order each is an anecdote about six vials; three orders each over a year is the beginning of a comparison.

Nothing here is medical advice, and research-use compounds are not approved for human use.

One laboratory, one method, one submission. Otherwise it is not a comparison.