Is BCH worth the price difference against GL Biochem (Shanghai) on measured results?

Details up front: BCH · GL Biochem (Shanghai).

I suspect the honest answer is that it depends, in which case I would like to know on what.

Assume I can obtain either option without difficulty, so availability is not the deciding factor.

Under what conditions does the answer flip?

Ratings on this site are ours alone and are deliberately not reconciled with anyone else's.

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

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

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.

No supplier on this site pays for its position, and the storefront links are marked nofollow and sponsored.

Use a fixed documentation checklist rather than an impression.

edited 2 Jul 2026 by loss_on_drying — removed a claim I could not source

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

Submitting to different laboratories introduces a method difference that commonly exceeds the supplier difference. Gradient slope alone can move a reported purity figure by a per cent in either direction.

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.

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

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

Worth being precise here: a single member running three suppliers on one method is worth more than thirty members running one supplier each.

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

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

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

The honest answer is that most claimed differences between reputable suppliers are inside inter-laboratory noise.

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

Inter-laboratory spread on identical peptide material is routinely half a per cent to a per cent by RP-HPLC, which is the noise floor for any cross-laboratory comparison.

Compare content, not purity. Purity clusters and content does not.