Caffeine

People over the age of 16 years can use caffeine to increase alertness, reduce fatigue and malaise, and enhance pain relief when used with acetaminophen.

Caffeine works by blocking the actions of adenosine, a natural chemical the body produces to signal tiredness. It is often included in many over-the-counter cold and flu remedies due to its effects of reducing fatigue caused by cold or flu, and in combination with other medications such as pain relief. It can be purchased in tablet form either as synthetic caffeine or as guarana (plant-based caffeine).

Caffeine should not be used by children under 12 years when it is found in cold, flu, or pain relief products. Caffeine alone is not recommended for use by anyone under 16 years. Caffeine should also be used with caution in those taking stimulant attention deficit hyperactivity disorder (ADHD) medication as it can increase the side effects of their medication.

As with any medication, some people are bound to get some unwanted side effects. Some of the common ones include insomnia, anxiety, irritability, nausea, headaches, and diarrhea.