Delayed nodules after Sculptra are a known complication, and they follow a timeline. This page covers how often they appear and when.
How often they occur
NCBI PMC reports that if a 3:1 dilution of Sculptra is used for injection, the occurrence rate of the late-onset Sculptra nodule is 1%.
That figure applies to one dilution. Ask your provider how your product will be prepared.
Early and late nodules
NCBI PMC states that nodule formation after injection of poly-L-lactic acid does occur and can be classified into an early-onset nodule, appearing 1 to 3 months after injection, and a late-onset nodule, appearing 6 to 36 months after injection.
The same source says the early type responds poorly to corticosteroids, while the late type responds well to intralesional corticosteroid injection.
Wider safety reading
For comparison with another injectable, a systematic review of adverse events reported after hyaluronic acid filler injections to the face shows how complication data is gathered. The FDA's dermal filler dos and don'ts is a plain consumer checklist.
If you find a lump
If you notice a lump after treatment, tell your provider rather than waiting. The timing of the lump helps them sort which type it is.
The one-to-thirty-six-month window
The answer changes with the calendar. Early nodules show up in the first 1 to 3 months, and late ones can appear anywhere from 6 to 36 months after injection.