Black Insomnia, a coffee company based in Africa exceeds the Food and Drugs Administration (FDA) - recommended 400mg per day limit of caffeine. The coffee contains 702 mg of caffeine per 12-ounce cup surpassing Death Wish coffee with 660mg.

Black insomnia coffee therefore over 1.7 times the recommended daily caffeine limit. According to Forbes, the caffeine limit pertains to the point at which an individual experiences side effects such as insomnia ( a basis of the coffee's name), peeing, upset stomach, headaches, diarrhea, heartburn, nervousness, anxiety, increased heart rate, and abnormal heart rhythms.

Black Insomnia and Death Wish coffee are not the only companies competing for the most caffeinated coffee. Companies such as Biohazard, Killer Coffee, Banned Coffee, Shock Coffee, Bone's Coffee High Voltage and Perk Coffee are also playing on top. Coffee is taken by millions of people for stimulation, alleviating fatigue, and improving concentration and focus.

Up to 400mg of caffeine is safe for healthy adults, which will account to four cups of brewed coffee. Black Insomnia, therefore, is not recommended to individuals suffering from underlying diseases such as hypertension, gastro-esophageal reflux disorder (GERD), ulcer and arrhythmia. Caffeine is safe for adults but not with children.

As reported by Coffee and Health, European Food Safety Authority (EFSA) advised that caffeine intakes from all sources including coffee and cola should only be limited to 400mg per day. Furthermore, 100 mg of caffeine may increase sleep latency and reduce sleep duration in some adults. In recent years, concerns were raised regarding the caffeine consumption especially in coffee among adolescents.

Cases of caffeine overdose prompted the FDA to raise warning regarding intake of caffeine in some beverages. In the first half of 2015, the case of overdose summed up to 1,675 involving energy drinks with close to two-thirds in the population of individuals aging 18 years and younger. On the other hand, coffee has also some benefits as it is considered to be an antioxidant fighting free radicals in the body.