A residual drug or alcohol phenomonon in which, during a period after a heavy binge, only a small amount of the recently-abused substance is needed to re-activate your buzz. So named after what happens in the shower when you "rinse and repeat": only a tiny bit of shampoo is needed the second time around to achieve a full sudsy lather.

When because of recent use, a little goes a long way. Usually referred to when re-gaining an alcohol buzz. (If you shampoo your hair and ever "repeat", you know how just a tiny bit of shampoo will cause instant lather? that's the shampoo effect)

what happens when you drink alcohol after previously drinking alot the night before and you get buzzed faster, similiar to when you shampoo your hair and if you wash it twice in a row the second time it gets alot foamier faster the second time

(noun) The effect of having that first drink the next day, after a long night of drinking, and it gives you a good buzz right away. Much like how quickly the shampoo lathers as you apply it the second time.

The effect when you drink alcohol the day after getting extremely drunk and it only takes you a quarter of the amount of alcohol to get you equally as drunk as the night before.