Is Four Sigmatic for real, or is it BS? That’s the question that the editors at OutwitTrade.com have answered in this excellent review of Four Sigmatic. Here’s the conclusion: there’s plenty of scientific evidence that Four Sigmatic can be good for your body, but there’s still plenty more work to be done. In fact, there’s yet to be a real independent study on Four Sigmatic, and in any case, it can’t be considered any kind of magic bullet.
Four Sigmatic’s main product, and best-seller, is their “mushroom coffee” which was fairly well received. According to the review linked above, it’s a great tasting coffee.
One of the interesting things about Four Sigmatic is that it was recommended by Tim Ferriss, and that’s probably what got the company off the ground. That, along with their fancy marketing around “superfoods”.