My recent visit to a new plastic surgeon produced great results (well, after 2 follow ups with additional product needed) using Juvederm XC in the cheeks, nasolabial folds, and lips. However, 2 months later, the product is completely gone!! That's a lot of money for 2 months of results! I've been using Juvederm for several years in those areas, but using a different practitioner---with my prior practitioner the results lasted 6-8 months. My recent dr must have diluted the product. Possible?