Doppelherz is German for "Double Heart".
It is also the
brand name for a line of
food supplements that are supposed to be good for your
cardiovascular system with ingredients like
lecithin,
garlic,
ginseng and diverse
vitamins. They are not classified as "real"
drugs, meaning they can be sold at any store, not only in a
pharmacy with a
prescription from a doctor.
The original "Doppelherz Energie Tonikum" was invented in 1919 (claims the website) - the manufacturer is the Queisser Pharma GmbH based in
Flensburg. The Doppelherz
logo is quite well known (at least in
Germany, that is) - take a look at www.doppelherz.de.