Heres some stuff that i found on the web about caffine in cosmetic products:
Caffeine is used as an ingredient in cellulite creams because of its distant relationship to aminophylline. Aminophylline is a modified form of theophylline, and both are bronchodilators (Source: Yale New Haven Health Library, Alternative/Complimentary Medicine,
www.yalenewhavenhealth.org); caffeine contains theophylline (Source: Progress in Neurobiology, December 2002, pages 377–392). There is no research to prove or disprove that theophylline can affect cellulite. Only its association with aminophylline and subsequently its relation to caffeine makes it a good, natural-sounding candidate for a cellulite cream. There are two studies showing caffeine to have benefit for cellulite, but one was conducted by Johnson & Johnson, which owns RoC and Neutrogena, both companies that sell cellulite creams that contain caffeine, and the other was conducted by cosmetic ingredient manufacturers that sell anti-cellulite compounds (Source: Journal of Cosmetic Science, July-August 2002, pages 209–218). There is no other independent research showing that caffeine provides any benefit for treating cellulite, nor research pointing to how much caffeine is needed to produce results. Besides, if caffeine were the answer, wouldn't consuming tea and coffee (without cream and sugar, of course) daily have an internal effect on cellulite? Couldn’t you just rub coffee on your legs or make a coffee ground scrub and get results? Wouldn't Starbucks have a whole new marketing angle to entice customers?
It also said that caffine can reduce puffyness.