I love this product. Since I've been adding one dropper full to my coffee every morning I have noticed a serious improvement in my "sharpness" (for lack of a better word). At work and in meetings, my mind just seems to work more quickly. Plus, since I've been using Slipstream Farms mushroom tinctures (I started with Lion's mane), I've only *almost* gotten sick once. And that was when I was traveling and did not bring it with me. The 2 oz. bottle seems to last a long time too!