you can- but your test levels will fluctuate drastically and it may effect your mood. it really depends on the amount you are injecting as well. test suspension has a half-life of 8 hrs., so when you inject, you will get a nice boost within that time constraint (up to 16-18 hrs.), but the next day, when you don't inject, your test levels will drop back to pre-injection levels (or below, once your testes shut down) and you won't get the positive effects of heightened test levels- you will gain some, but is really like taking 1 step forward, 1 step back