Stimulants are sometimes referred to as uppers and reverse the effects of fatigue on both mental and physical tasks. Two commonly used stimulants are nicotine, found in tobacco products, and caffeine, an active ingredient in coffee, tea, some soft drinks, and many non-prescription medicines. Used in moderation, these substances tend to relieve malaise and increase alertness. Although the use of these products has been an accepted part of U.S. culture, the recognition of their adverse effects has resulted in a proliferation of caffeine-free products and efforts to discourage cigarette smoking.