The page is unusually candid about this.
What it says
It states that no published finished-product clinical trial was located for Quiet Nerves itself and that ingredient amounts are not printed.
What it means
Evidence is indirect: studies on individual ingredients at their own doses. That is common for supplements, but it should shape your expectations. It does not mean the product is unsafe or useless. Use the guarantee and ask your doctor.
Educational note: This guide is general information based on the Quiet Nerves page. Statements have not been evaluated by the Food and Drug Administration. The product is not intended to diagnose, treat, cure or prevent any disease. Individual results vary.