Heat sterilization is the simpliest way to sterilize injectable AAS. The typical way to do so is to place the AAS vial in the oven for 30 min at 250 degree F. Leave a needle sticking through the rubber stopper to equilize pressure inside the vial, or it may break. This should kill most bacteria, and can be regarded as a viable harm reduction strategy.
Other choose to use the top of the stove to heat sterilize. You submerge the AAS vials in a pot of boiling water 212 degrees F. Keep the vial kept in the water for approximately 20-30 minutes. Though this will kill many forms of bacteria and microorganisms it is not considered the best method of doing so. A higher temp should be used. Also if the vial sits on the bottom of the pot it will be in direct contact with the heat source which will make it hard to control the temp in the vial.
Note that tren breaks down at fairly lover temps. It begins to degrade even at 212 degrees F. Tren should be heat sterilized under different conditions . Typically baking the vial in an oven for two hours at 175 degrees F. Again an unattached needle should be placed in the rubber stopper.
Another way to sterilize is to use a syringe filtration. .22 micron filters allow for the removal of all most all forms of bacteria. If you want me to go into detail of how to do this let me know and I will post it up.
Keep in mind these methods are not without flaw. For example you have to be careful not to contaminate your own gear while doing filtering your AAS. Also many forms of bacteria are small and hardy enough to survive these techniques. The safety methods I stated are highly effective, but not necessarily complete. To be safe it is best to use legitamite pharmaceutical products.