Laughter isn't the best medicine because laughter can't halt an allergic reaction or dry up that infection that's been brewing for months. In a less literal sense, laughter doesn't bring your boyfriend back or help you lose 20 lbs before your reunion.
The best medicine is whiskey or meditation - anything that takes you away from the itching, the heartbreak and the weight gain. A Z-pack is also really handy for sinus infections or bronchitis.