[steveBK123]

Love a good conspiracy & not a biologist / chemist, but I don't thing such a drug is even possible in our current state of technology.

Treatments that are "one (or N) & done" tend to be surgical procedures which physical change your body or vaccines which train your immune system (which has a sort of viral memory bank).

Most other regular drug treatments are introducing chemicals into the body which your body consumes/breaks down/etc. The body is always self repairing, replacing cells, etc.

As a layperson, I conceptualize altering brain chemistry via a drug is a temporary thing the way adjusting your pools chemistry is. You have to constantly replenish with new chemicals as everything is constantly breaking down and changing.