The 43-year-old beautician, of Lippstadt, injected her 29-year-old client with several syringes of anaesthetic during a hair-removal session in mid-January, the district attorney's office in the city of Paderborn in North Rhine-Westphalia said on Friday.
The injections nicked a vein, according to prosecutors, sending the anaesthetic into the woman's bloodstream. She went into cardiac arrest and died a week later in the hospital.
Investigators said they were unable to determine whether the woman had agreed to the injections, but even if she had, the beautician was not authorized to perform them. The 43-year-old faces charges of doing bodily harm with fatal consequences and violating laws that govern alternative medicine.
The beautician has not commented on the charges. A trial date has not yet been set.
Germany's parliament discussed stronger government oversight of cosmetic surgery last month, with both the conservative Christian Democrats and the center-left Social Democrats saying rules should be more strict, especially for minors.