Upon ingestion, aspartame is metabolized to formaldehyde in the body and has been reportedly associated with systemic contact dermatitis in patients exquisitely sensitive to formaldehyde.

Aspartame can be found in instant breakfasts, breath mints, cereals, sugar-free chewing gum, cocoa mixes, coffee beverages, frozen desserts, gelatin desserts, juice beverages, laxatives, multivitamins, milk drinks, pharmaceuticals and supplements, shake mixes, soft drinks, tabletop sweeteners, tea beverages, instant teas and coffees, topping mixes, wine coolers, yogurt.