Use some sterile cottonseed oil. Cut it down to 250 mg/ml. That should be easy as you will just be about doubling the volume of the solution. The amount you add will be a little less than the volume you have now since the test powder itself takes up some volume. I forget how you figure that. YOu should be able to figure that out by doing some searching.
yea bro you gotta cut it in half. I tried some high does SHIT one time from china and it fuckin hurt so bad , first shot in the glute was sore for 7-8 days and left a big knot for 2 weeks , second shot opposite glute same shit !! i ditched it after that.
You want to add the exact amount you have now if you want 250/ml, as the powders already been accounted for.
so if you've got 10ml every 1ml is 500mg test so you'll still need to add 1ml each ml to make it 250mg so another 10ml in total.
One problem you could have, you may make it crash as you'll be halving the solvents, but I assume there so much solvent in it already to keep it from crashing at such high mg per ml that you'll be ok.
Are you using other AAS with this or only the sus? If you are using more you can draw another oil based AAS into the syringe with the sus and that can definitely help. Also you can purchase sterile oil and mix with that. It has worked for me in the past.
My bro and I came across some 400 a few years ago...and yes the gains were good and sollid but the pain was something else (and I thought I had some good pain tolerance)...in the end we ended up mixing with another AAS so that we could not only squat again but to make walking and sitting a little less obvious.