N2Guard=milk thistle. Read the label and dose it how it tells you. Androgen receptor sensitivity is effected 4 hours after you take it so figure out what works best with your schedule.You can always take something like liv52 which is a great support supplement that lacks Milk Thistle. I would suggest preloading with milk thistle 2 weeks before your cycle though as to prepare your liver.
Also, Helladrol common cycling protocol is for 6 weeks. I hope you are educated on this pro hormone and you have a proper PCT. If you don't know what I'm talking about,start researching.