I'm halfway thru the 42 day cycle, also taking with animal stake and I'm impressed with the results. Noticing strength gains and increased endurance and stamina. I will cycle m-stake when finished, I was sketchy about the animal products, but I've been sold a solid product and am a satisified customer. I have noticed slight headaches lately but very manageable. I'm also taking animal pak and pm, highly recommended by uys I lift with. I'm very happy with this.