I beg to differ. I recall splitting a 5th of jager with a buddy many years ago, during a ride up to NH (we were chilling in the back, btw) from NC. I believe we started somewhere ~Connecticut, and this was back when I could drink with limited ill effects.
I did not have a fun morning.....
However, if there is something in the jager to limit the hangover effects, I wouldn't be too surprised. The rumor (well, it is a rumor), is that it has traditional medicinal uses in Germany. I couldn't confirm this when I was there, so I'm just saying. There are other similar liquers in other countries that have a very long-standing history of medicinal use, however.
Balzams, which comes from Latvia, can be found in just about every house in the country, and tends to be reserved as a salve for wounds and a teaspoon tonic for just about any illness that comes about. It's basically jager on crack--super spicy and harsh. ....and tasty
(and if you read that wiki article, you'll learn that it may have been used to cure Catherine the Great of illness, thus allowing her a quick and speedy recovery from all that horse-fucking

)