The ingredient list is the real spec sheet
Ingredients are listed by weight, largest first. That order is the honest summary of what a formula emphasizes, and it is the one part of the packaging that is hard to write around. A product with ginseng first and Ginkgo biloba last leans toward ginseng. If the front label promises stamina but the list is thin, the list wins.
This habit alone separates an informed purchase from an impulse one. Reading supplement labels takes about a minute once you know what you are looking for: scan the order, note the two or three ingredients that carry the product, then check whether the front of the bottle actually matches what is inside.
One habit worth keeping
Read the list from the top and stop at the first ingredient you cannot identify. If the two or three leading ingredients are not the ones the product is sold on, the formula is not aimed at the goal the front label implies.