How we check

Every number on this site comes from a brand's own label, run through the same math. Here it is, so you can check our work.

1. Read the label. We record each active ingredient and its amount per serving exactly as printed, and the dose the label gives for each dog weight. We read the brand's site, a retailer page, or the label photo on the product listing, and link the one we used.
2. Per serving. Many labels list amounts per 2 chews. We divide by the number of chews in that serving. If a label only gives amounts for the whole jar, we don't use it for per-day math.
3. Per day. Amount per serving times the label's own number of servings a day for that weight. We use the maintenance dose; a "loading" dose for the first weeks is shown separately where it matters.
4. Cost per day. Amazon price divided by the servings in the container, times servings a day. We use only listings sold by Amazon.com or the brand's own store, and show the date we read the price.
5. Compared with studies. Where a published study used a dose, we show it next to the label dose and link the study or the review we read.
6. NASC Quality Seal. From NASC's own member list: members with a green check have passed NASC's quality audit and may show the seal.

Medical advice

• We don't give medical advice. Supplements can interact with medicines; ask your vet before starting one, especially for a dog with a health problem.

Last updated October 28, 2026.