He's become one of biohacking's greatest hype men, spreading the gospel through a massive podcast, a best-selling how-to book, and an annual conference that increases in size every year.

After a few sips, I started to feel giddy, and almost high - as if I could run a marathon and deliver a keynote lecture and do my taxes, all at once.

If you're the kind of person who requires caffeine before conversation in the morning then perhaps you might be tempted to try a buttery new brew to increase your brain power.