D Aspartic Acid is a very good legal and effective testosterone booster. Recent human studies suggest that 3 grams daily for 12 days will elevate testosterone up to 40% and LH up to 33%. The problem is that is testosterone increases there will always be the chance of aromatazation and especially if this happens this fast.
I would use DAA at 1.5g daily for 24 days then take a break and use some sort of PCT or do a 12 day cycle then do a mini PCT then cycle again.
I like this compound because there is human studies to back it up, also