I don't like the premixed sustanon powder, I prefer to use all separate compounds and mix them myself. The premixed stuff is usually made with test base instead of test iso, so make sure you have test iso sustanon and not test base sustanon. The reason is test base will crash after a certain dosage, and another thing is test base is cheaper than test iso, this is why a lot of premixed will be test base sustanon, it gets the manufacturer more profit of that product than it would if it was test iso. I would suggest you ask the supplier you got the premix from and find out if it is test base or test iso so you use the right recipe and so you will know how to do your calculations in regards to dosage so it wont crash. If you get separate compounds and mix them together yourself you could control which compound gets raised higher to get a higher dosage and not have it crash by raising all of them in a premix and possibly having it crash on you.
Thanks
TMM