Price tags on supplements are designed to be hard to compare, and the defense is a single piece of arithmetic you can do in your head: cost per serving. It is the great equalizer, because it strips away bottle size, capsule count, and front-of-label theater, and leaves one number you can line up against any competitor.
The formula is just the total price divided by the servings per container. Note that it is servings, not capsules, not grams, not days unless a serving happens to be a day. A forty-five dollar bottle with ninety servings is fifty cents per serving. Hold that number. It is the only one that matters for the value question.
Here is where bottles play tricks. Imagine two generic products. The first is twenty dollars for thirty servings, which is sixty-seven cents per serving. The second is thirty-five dollars for seventy servings, which is fifty cents per serving. The second costs more at the register and less per serving. The sticker price ranked them backwards, and only the division told the truth.
Now layer in the normalization from comparing forms and amounts. If one product needs two servings to reach the amount another delivers in one, double its cost per serving before you compare. A product at thirty cents per serving that requires two servings is really sixty cents per effective unit. The cheap-looking option just doubled.
Be suspicious of any value framing that uses cost per capsule or cost per bottle instead of cost per serving. Cost per capsule flatters products with tiny capsules. Cost per bottle flatters big bottles regardless of how concentrated they are. Both are chosen precisely because they hide the serving denominator, which is the one that makes products comparable.
Finally, remember that cheaper per serving is not automatically better, and pricier per serving is not automatically a rip-off. The math tells you what you are paying, not whether you should buy it at all. Whether a given supplement belongs in your routine is a decision for a qualified healthcare professional. Cost-per-serving math just makes sure that, once that decision is made, you are not overpaying for the same thing in a fancier jar.