The 1980s pop star sued Harley Street surgeon Dr Maurizio Viel after suffering swelling and blisters caused by the treatment.
Last week the doctor's legal team admitted to the High Court that Pete was not properly warned of potential side-effects of the product called Outline Original.
Dr Viel also failed to observe guidelines about its use in conjunction with other products, and gave an excessive number of follow-up injections.
Pete claims he was forced to sell his musical back-catalogue because he was unable to work, and will also be suing Dr Viel for financial losses.
Auriana Griffiths, from firm Irwin Mitchell, said: "The barrister representing Dr Viel confirmed last week in court that the allegations of negligence set out in the original documents filed at court have been admitted.
"At this stage, the investigation into the value of the case is ongoing and no figure has been agreed."