A coffee drink has been introduced in the US which is described as probably the strongest coffee in the world. A cup of this drink could reportedly put you over the daily caffeine limit. 

Sean Kristafor, the creator of the so-called Black Insomnia, admitted that he would like to be the "-est" in the world looking for only the best.

"If you want to stand out, you need to be the 'est' -- the biggest, smartest, strongest, or cheapest," he said during an interview with CNN. "So when we wanted to compete in coffee, as a caffeine product, we had to be the strongest, but obviously, we don't exceed the world guidelines."

Black Insomnia was first made available in Cape Town, South Africa. Because of its unique offers, about least three tons of the coffee was sold in August. This is way greater than the performance of other local shops in Cape Town. Now, Black Insomnia is being shipped to 22 countries worldwide.

Black Insomnia has also been listed on Amazon and is confirmed to have sold five to six tons of coffee per month.  

Despite its popularity, experts have warned consumers to be cautious of Black Insomnia. The said coffee could contain up to 702 mg of caffeine, which is high compared to the usual intake of 400 mg daily.

On the other hand, Aquaspresso has stated that Black Insomnia is the strongest coffee ever.  Researchers have stated some of the effects that the have coffee could give to its drinkers.

"This makes it easier to consume more caffeine than you intend to and effects can range from mild to severe, for example, jitteriness, nervousness, restlessness and trouble sleeping. The most serious effect would be cardiac arrhythmia (irregular heartbeat)," Mary Sweeney, a researcher from Johns Hopkins School of Medicine, said.