Front-of-bag claims are marketing. The back is where you find out what you are actually buying. Five things to check, in order.
1. Is there a proprietary blend?
If the active ingredients are grouped under one total — 'Calming Blend 480 mg' — you cannot know how much of anything you are giving. That formatting exists to hide low doses of expensive ingredients behind high doses of cheap ones.
Look for a per-ingredient amount on every active.
2. Where does melatonin sit?
Melatonin is a sleep signal, not a calming agent. If it is high on the list, expect a drowsy pet rather than a settled one, and expect the effect to disappear when the drowsiness does.
3. Are the doses meaningful?
Chamomile at 5 mg is decoration. It is there so the word can appear on the front of the bag. Compare the number against what studies actually used, not against the other product on the shelf.
4. What is the serving size?
A bag of 120 chews sounds generous until you read that a 60 lb dog needs three per day. Always convert to cost per day before comparing prices.
5. Who made it, and is it tested?
Look for manufacture in a GMP-certified facility and third-party batch testing. Supplements for animals are not pre-approved by the FDA, which puts the burden of proof on the manufacturer — and on you.
One more thing: the guarantee
A 30-day guarantee that requires you to ship the product back tells you the company does not expect you to still be using it at day 30. Anything working on a stress baseline needs longer than that to judge.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.