No. You can buy Quercetin with Zinc.
Side note: Just because 2 things are in the same pill doesn’t mean they should be. I have read conflicting info about zinc+calcium, but I used to have pills with zinc+calcium+magnesium.
I have no opinion/knowledge on whether Quercitin and zinc can/should be taken together. That’s on my list for future research along with the magnesium and calcium issues.
So my point is not about what should/should not be taken together, but just that I wouldn’t trust the vitamin/mineral manufacturers putting them together as a sign that they are ok together.