Caffeine is one of, if not the most, used drug in our lives, and it is commonly found in drinks, specifically, coffee. While some research has proven that including caffeine into our diet can provide multiple health benefits, such as increased alertness and vigilance, it is still important to manage our consumption of the addictive drug, as the complications of consuming it excessively can be quite detrimental. 
Effects of excessive caffeine:
Increased heart rate (and blood pressure in strenuous exercises)
Increased loss of calcium and magnesium which could eventually lead to muscle contraction and muscle cramping, respectively.
May cause anxiety or panic disorder
Possible mood swings
Osteoporosis (caffeine can lead to bone fracture if consumed too excessively)
So, how much caffeine would be considered too much that it would risk our health? While there has yet to be an accurate measurement of how much caffeine an individual can safely consume, experts recommend a moderate intake of 400mg per day (300 mg per day or less for pregnant women). It is also important to never go beyond 10 grams of caffeine as this is a lethal dose of caffeine for humans.  Some symptoms of excess caffeine include:
Additionally, if you decide to withdraw from caffeine, it must also be done gradually to avoid unwanted complications, such as headache, fatigue, decreased vigor, increased stress, and lethargy. [2, 3]
Despite these mentioned precautions, caffeine is still deemed as a harmless drug, if consumed moderately. It has been known to enhance performance in sports, improve mental functioning, such as vigilance and responsiveness, facilitate the performance of impulsive individuals, and impair the performance of non-impulsive individuals. [2, 3] As long as we are aware of how much caffeine we are consuming each day and how our body reacts to it, caffeine calls for no necessary warnings in our day to day lives.
1. Smith, A. (2002). Effects of caffeine on human behavior. Food and chemical toxicology, 40(9), 1243-1255. http://cedec.umfcv.ro/files/e/f/Effects%20of%20caffeine%20on%20human%20behavior.pdf
2. Nawrot, P. Jordan, S., Eastwood, J. Rotstein, J., Hugenholtz, A., & Feeley, M (2003). Effects of caffeine on human health. Food Additives & Contaminants, 20(1), 1-30.
3. Sinclair, C. J., & Geiger, J. D. (2000). Caffeine use in sports. A pharmacological review. J Sports Med Phys Fitness, 40(1), 71-79.
Author: Georgia Sukendro
Editor: Lauryn Agron
Health scientist: Keeana Bacchus