This medicine is no magic bullet — don't expect to be cured the moment you take it.
Tips
history
From the Yuan play 《玩江亭》 (anonymous): "灵丹妙药都不用,吃的是生姜辣蒜大憨葱" — no need for magic elixirs; what we eat is ginger, garlic, and scallions. The phrase comes from Taoist alchemy (丹 refers to cinnabar-based elixirs) but is now mostly figurative.
usage
Most often used in the negative (没有…的灵丹妙药) to push back against "one-shot" thinking. Also common with 把…当作灵丹妙药 — "treat X as a cure-all."