Oneal Ron Morris, 32, accepted a plea deal for one count of illegal practice of health care in what became known as the "toxic tush" case, in Miami Gardens, Florida.
Another suit is pending against Morris, involving the death of a woman who was one of her patients.
Prosecutors said Thursday they could not determine exactly what substances Morris injected in women, many of whom were transgender.
"I think the media picked up on a key word and ran with it," her lawyer, Michael Mier, told the court. "There was no evidence of Fix-a-Flat or Super Glue."
An image that circulated widely in the US press last year showed the woman at question, whose face was altered and who had a grossly swollen rear end.
Photos of Morris, who apparently injected herself with the same toxic mix as evidenced by her large, misshapen hips, also gained traction in the media.
Morris must surrender to authorities on January 7. For the moment, it is not clear what will happen with the murder charge Morris faces for the death of a patient in Broward County, north of Miami.
Morris first came to the attention of authorities in May 2010, when a woman who paid $700 for an operation to increase the size of her buttocks ended up in the hospital with pneumonia and grossly deformed hips, among other issues.
At the time, doctors said her buttocks had been injected with adhesive, tire sealant, mineral oil and cement.
After the story was publicized by the press, Miami Gardens Police reported last year that they had received hundreds of calls from victims of Morris and other supposed doctors who perform the same type of operation in private homes and even hotel rooms in Florida.