Benzyl alcohol is used as a bacteriostatic preservative ,without BA ,it's almost impossible to keep the oil in sterile .However ,too much BA would make it painful to inject ,and may also cause post inject soreness.

One client told us he feel so pain when injecting test prop ,and he is thinking if he could lower the BA ratio ,maybe to 1% ,would that work OK ? He has used test E ,but feel no pain.

Any opinion is welcome.