First dose

How much should I take for first dose? I’ve been sitting on some powder for a while but have never taken it, due to not knowing where to start. I take a lot of 7, some days like 500mg, over 120mg per dose. So I figured starting with like 30-50mg of this would be good for the first time. I just didn’t want to take too much because I heard this lasts a lot longer. Thanks so much, happy dosing.