Notes: The second needle equalizes the pressure as the solution enters the vial. Apply pressure to the syringe plunger to the filter the mixture. This is the most important part of this entire process as it is what sterilizes your product. All finished steroids from any steroid lab must go through this very one may find that the filter gets blocked or that the process slows drastically-it is acceptable to replace the filter with a new one if this occurs to save time. The time it takes to filter steroids depends on which steroid is being filtered and how much is being filtere, as well as the mg/ml of the the product is filtered in the sterile vial the process is complete.