Lion's mane mushrooms are a potent nootropic, potential antibiotic and anti-cancer agent, powerful antioxidant, and an immunostimulant. One of the most powerful nootropics I have ever used and a compound I personally enjoy.
If you want to try an extract from these I recommend FourSigmatic and if you use the code "scinutrient" at checkout you will get 10% off. Full disclosure, I do receive a small commission if you do this.