I have tried Volufiline products. If you read the marketing part, it claims to increase the size and number of fat cells. Then if you read the studies they cite, the increase is something like 0.08%, which is less than 10% of 1%.
The fillers are along the lines of silicone that are injected into the tissue. It does get absorbed or degraded over time, so maintenance injections are needed. I have considered this option many times. My non-VA dermatologist does them in her office. Because they are a cosmetic procedure, the VA won't cover it. I will have to save up for the out-of-pocket costs.