It's hard to say. Hangover patches have never been put to a clinical study, as far as we could ascertain.
"The ingredients used in making these are commonly found in multivitamins," Richard Honaker, M.D., chief medical officer, Your Doctors Online, says in an email. "When it comes to medical research, there is no scientific evidence that these patches work. There is also little evidence to prove that vitamins can effectively absorb through the skin. Hence, the idea of their delivery through a patch is more of a placebo effect, in my opinion."
Although definitely not a scientific study, HowStuffWorks enlisted our social media manager Khiry Clements, who put a RallyPatch sample to the test. He applied the patch, then imbibed on a work night, consuming two shots and a drink, totaling 9 ounces (266 milliliters) of alcohol.
"The experience seemed normal. It was like a regular night of drinking and a regular morning waking up. It seems to have worked," Clements reports. "If I know I have a night of heavy drinking ahead, I'd probably do it again."
It's also important to note that products like these aren't scrutinized by the Food and Drug Administration (FDA) in the same manner as medications. "Since RallyPatch is not intended to prevent, diagnose, cure or treat any medical illness or disease, the FDA does not evaluate the statements of the product," the company's website states. "RallyPatch is manufactured at a FDA regulated pharmaceutical company which always adheres to strict quality control procedures."