How much caffeine is too much? We all drink caffeine through coffee, sodas, and teas to help us get an edge on a sleep deprived day or perhaps just enhance our performance. Consider the fine line between too much caffeine or too little. Performance, whether intellectual or fine motor skills, can be increased to an optimal level. There is a happy median between too little caffeine and too much. This can go for all stimulants in general, but for the purposes of this article, I will focus on caffeine. Have you even had one cup of coffee and felt alert to the point of being at an optimal level of intellectual performance? Then on the other hand, had too much coffee and felt frazzled/ unorganized? This isn’t your imagination and can be explain in the graph below:

Image source: Fig. 6.4 of

Ksir, C., Hart, C.L., & Ray, O. (2008) Drugs, society, and human behavior (12^th Ed.). Boston: McGraw Hill.

As caffeine levels rise, you become more alert and performance appears to increase (Both intellectually and physically). Caffeine levels continue to rise and you become more excited. Performance starts to fall at this point and drops dramatically furthermore as dose increases. Examples of this can include jumpy selective attention, jittery body movements, and increased heart rate. It’s also very hard to concentrate on a complex cognitive task. ie: reading/writing/critical thinking.

In conclusion, be aware of your fine line between under stimulation and over stimulation. If you are planning to get something done and think the more caffeine you have the better, be aware of this model. Performance and organization can suffer with an overabundance of caffeine. This idea is further illustrated with a non caffeinated and caffeinated spider pictured below making its web:

Image Source

Content Source:

Ksir, C., Hart, C.L., & Ray, O. (2008) Drugs, society, and human behavior (12^th Ed.). Boston: McGraw Hill.