Mar 28, The company says it packs milligrams of caffeine into 12 ounces of coffee. With mg of Caffeine, Black Insomnia Coffee is The World's Strongest Coffee, certified by Caffeine Informer and other science people. Apr 3, Black Insomnia Coffee claims to be the "strongest coffee in the world," with percent more caffeine than your morning Starbucks. ADDERALL VS. THE STRONGEST COFFEE IN THE WORLD Apr 3, The "world's strongest coffee" is now available in the US, but just one cup could spill you over the daily caffeine limit. Apr 12, Death Wish Coffee: Call us biased, but being 'The World's Strongest Coffee' means so much more to us than caffeine content. You can find. thecoffeedrops.com: Death Wish Ground Coffee, The World's Strongest Coffee, Fair Trade and USDA Certified Organic, 16 Ounce: Grocery & Gourmet Food.