Most of the time you don't start from ingredients. You start from a customer who wants Euphoric, or a mix you saw someone post, and you need to know what produces it. Working that out by hand means guessing combinations in the Mixing Calculator until something lands.
The Effect Finder does it the other way round. Name the effects you want, and it searches every combination of the 16 ingredients across the 7 products to find the recipes that produce them - then ranks what it finds by profit, margin, cost or ingredient count.
How the search works
The finder runs the same transformation rules as the game, in the same order. It builds mixes one ingredient at a time, and keeps the ones whose final effects contain everything you asked for.
Two mixes that end up identical are only explored once, and ingredients that would change nothing at that point are skipped. That is what makes the search finish in a fraction of a second instead of enumerating the hundreds of millions of possible orderings.
Order matters, so the shortest recipe is rarely the obvious one. Getting Euphoric onto OG Kush takes Gasoline then Cuke: Gasoline adds Toxic, and Cuke turns Toxic into Euphoric. Cuke alone would never produce it.
34 of the 35 effects can be reached this way. Lethal is the exception - no ingredient produces it, by default or through any transformation - so it is left out of the picker rather than returning an empty search.
Using the finder
Mark the effects you want with the check, and the ones you want to avoid with the cross. Avoided effects are useful when a mix keeps picking up something that drags the price down or that your buyer refuses.
Optimize for and Sort by are not the same control. Optimize for decides which recipes the search keeps when it hits the results limit; Sort by only reorders what came back. Searching for Euphoric optimized by margin surfaces recipes above 2,000% that a profit-optimized search drops before you ever see them - so if you care about return on spend, set it before searching, not after.
The mix slider caps how many ingredients a recipe may use. Lower values return cheaper, faster recipes; higher values open up combinations that need several transformations to line up. If a search comes back empty, raising it is usually the fix.