The large gap time doesn't make sense.
How Does a Study Conclude That Radiesse Can Last from 6 Months to 5 Years?
Doctor Answers 3
When someone talks about duration, it’s important to know what they mean
When someone talks about how long something lasts, it depends on what they mean. If you look at nasolabial fold correction, it may start to go away in as soon as 6 months. However, if you look at a biopsy of the product, you can find evidence of the product still present 5 years later (even though the appearance of the correction may be gone). So when someone talks about duration, it’s important to know what they mean.
Radiesse can last more than a year
When the company first launched the product there was mention of it lasting up to two years or more. Clincially we tend to see it lasting somewhat longer than 12 months, but as with all fillers that are not permanent or semipermanent fillers, the product will continually decrease in volume so that it is important to say what percent of the product persists at the time frame indicated. As an example, if one were to say that 5% of the Radiesse still existed at three years, would that make the patient or the physician say that is a good clinical outcome? The practical consideration dictates that most people need to have Radiesse injected about one year after treatment. I see some patients that retain 10 - 20 % of their Restylane or Juvederm after one year too.
There are anecdotal reports that in some patients radiesse have lasted more than one year.
I am not aware of a scientific study.