Well here is an abstract from a study i found. The study goes back a long ways, maybe you can find more recent stuff. (asprin seemed to enhance E's effectiveness, but did little by itself. Dunno if similar effect w/ C):
American Journal of Clinical Nutrition, Vol 45, 564-569, Copyright © 1987 by The American Society for Clinical Nutrition, Inc
ORIGINAL RESEARCH COMMUNICATIONS
Aspirin as a promoter of ephedrine-induced thermogenesis: potential use in the treatment of obesity
AG Dulloo and DS Miller
Chronic administration of aspirin to obese mice had no effect on energy balance and body composition. In contrast, ephedrine increased energy expenditure by 9% and reduced body weight and body fat by 18% and 50%, respectively: obesity, however, was reduced but not reversed. In the presence of both ephedrine and aspirin, increase in energy expenditure found during treatment with ephedrine alone was doubled, and the obese group lost greater than 75% of body fat: obesity was reversed. These studies indicate that although aspirin administered alone has no influence on energy balance it can markedly potentiate thermogenic properties of ephedrine, effects which led to a normalization of body composition of the obese to that of the lean. Such ephedrine-aspirin mixtures, often found in over-the-counter preparations for asthma and bronchial disorders, could be put to new use as aids for treatment of human obesity.
Please Scroll Down to See Forums Below 
