A student cut off his penis and tongue with garden shears while tripping on an hallucinogenic drug.
Doctors were unable to re-attach either his penis or tongue.
The student has been named only as Andreas, from Halle.
His mother said: “Andreas was behaving normally the whole day until he left the house and disappeared into the garden for a couple of minutes.”
When he returned to the house he was wearing a towel wrapped around him and was bleeding heavily from his mouth and between his legs.
Angels’ Trumpet is the latest drugs craze to sweep Germany.
Doctors said the teenager would need years of support.
Dr Andreas Marneros, from the local psychiatric hospital where the student was admitted to, said: “Andreas will have to receive psychological help for years.
“Tea from Angels’ Trumpets is extremely dangerous as the drug cannot be dosed.”