If the layers of connective tissue beneath the skin on the thighs are indeed the main cause of cellulite (along with excess or poorly formed fat deposits), then improving skin structure should, theoretically, make a difference. There is growing evidence proving this to be the case. Retinol (the entire vitamin A molecule) or the prescription derivative tretinoin found in Renova or Retin-A, make up a group of ingredients known to help improve skin structure. When it comes to cellulite there are limited studies showing tretinoin to have benefit, though even then only a small improvement, but theoretically it should help and it’s absolutely better than most other topical alternatives.
Of all the ingredients to look for in a cosmetic cellulite product, retinol should be at the top of the list. However, most cellulite products contain (at best) teeny amounts of retinol, and are often in packaging that won’t keep this air-sensitive ingredient stable. One other point: Johnson & Johnson has a study showing the combination of retinol, caffeine, and ruscogenine can reduce the appearance of cellulite. Of course J&J-owned company RoC sells cellulite products with that combination of ingredients. (Sources: Journal of Cosmetic Science, July-August 2001, pages 199-210; American Journal of Clinical Dermatology, November – December 2000, pages 369-374; and Journal of the European Academy of Dermatology & Venereology, July 2000, page 251.)