Beginning next week, PepsiCo Inc. will start shipping aspartame-free Diet Pepsi to stores following concerns that the artificial sweetener can cause health problems including cancer. 
The reformulated Diet Pepsi will contain sucralose and acesulfame potassium, which are ‘less controversial sweeteners.’ The front of the new Diet Pepsi can declares “Now Aspartame Free” and PepsiCo will continue to announce the change on in-store advertising trumpeting the company’s sponsorship of the National Football League. The beverage maker will also remove all remaining aspartame-containing products from stores.
PepsiCo says it will market the new Diet Pepsi “aggressively” via sampling campaigns at stores around the country starting next week.
The company decided to make the switch after its consumer surveys showed that aspartame – also known as Equal and NutraSweet – to be the No. 1 reason that Americans are drinking less diet cola. Research has shown that aspartame causes tumors in rats, but the FDA has continually defended the substance, saying it is perfectly safe.