A blend is not a compound. It is two or more separate peptides dried into the same vial, and almost everything that makes a certificate meaningful gets more complicated when you do that.

A purity figure for a mixture is not a number

Purity means the fraction of the material that is the thing you wanted. In a vial containing two peptides, both are the thing you wanted, and a single figure covering both tells you nothing about either. A blend certificate should report each component separately, with its own peak and its own percentage.

The weights have to be separate too

A vial described as 10/10 mg should say which ten is which. CJC-1295 with ipamorelin at twenty milligrams total is a different product from one at twenty milligrams of something else, and the only way to know which you have is a certificate that breaks it out.

Why blends exist

Mostly convenience and price: one vial, one reconstitution, one shipment. The KLOW blend is four peptides that would otherwise be four vials and four separate lots.

What you give up

• You cannot change the ratio. The proportions are fixed at the point of manufacture.
• One component degrading takes the vial with it, and they do not degrade at the same rate.
• A single lot number now covers several different syntheses, so a problem with one component is invisible in the lot as a whole.