Insulin can be utilized effectively in 4 week periods. Most dont reccommed any longer without a break in between. The types you want to use are fast acting insulins. Humalog or Humulin-R. 10 grams of carbs per I.U. injected is considered standard. Injecting post workout is when Insulin is effective. Now that that's out of the way, wait a little while on the insulin, its possible your brother is on a much longer acting insulin, and tampering with longer acting insulins is dangerous and unnecessary, plus i dont agree with using a substance that one doesnt have a functional understanding of. There are great threads in the educational forum on Insulin. Take the time to read them.