How the Tested Index scores vendors

Which batches count

• Only vials Tested.ph buys anonymously, through the vendor's normal checkout. Vendor-submitted and buyer-submitted records are published but never scored, because the sender chose the vial.
• Only batches published in the last 12 months.
• A batch with no identity, purity or amount result is left out, except an identity failure, which always counts.
• Vendors that share an owner with Tested.ph are never ranked. Their records are published and labelled.

How one batch is scored

Identity failure scores 0. If the vial holds the wrong molecule nothing else about it matters.

Otherwise the batch gets four components, each out of 100, weighted as follows:

• Purity, 35%. 0 at or below 90% HPLC purity, 100 at or above 99%, linear in between.
• Amount accuracy, 35%. 100 within 2% of the label. Beyond that each percentage point under the label costs 4 points and each point over costs 2. Underfilling costs twice as much because the buyer pays for milligrams they do not get.
• Consistency, 20%. How much the measured-to-label ratio varies across the vendor's passing batches. Each percentage point of coefficient of variation costs 10 points. With fewer than two passing batches it is set to 50.
• Transparency, 10%. Whether the vendor publishes batch-specific, verifiable reports, names its lab and answers right-of-reply requests, scored 0 to 1.

From batches to a vendor score

The vendor score is the weighted average of its batch scores. Recent batches count more: a batch's weight halves every 6 months. A vendor is ranked once it has 3 scored batches in 12 months; below that it is listed as insufficient data, without a grade.

Grades