This is unusual since 400 MG of any testosterone ester would not be soluble in a single milliliter of any oil. From the injection site irritation users reported it is very likely that the manufacturers have increased the benzyl alcohol content as a means of increasing total testosterone esters possible, dosage wise, for solubility. More bang for your dogy’s buck, but more burn also. Athletes who experienced higher sensitivity to injection site irritation from benzyl alcohol usually mixed "Test 400" with Synthol, Protest, or another oil based AAS to reduce irritation. But doing so required a siteinjection type protocol.
As said several times prior, testosterone is testosterone regardless of brand or ester the active drug is joined to. The question is a matter of chosen active-life and dispersion profile, with the chosen blood serum or plasma level desired. Sounds confusing but it is not. For example: Testosterone Enanthate and Cypionate are testosterone joined to an ester to create a time-release effect. For this reason, Testosterone Enanthate provides 144 MG of free testosterone per 200 MG dosage and Testosterone Cypionate provides 140 MG of free testosterone per 200 MG dosage. So actually 200 MG of Testosterone Suspension is about 30% more powerful simply due to the fact that suspension is raw free testosterone in sterile water, and 200 MG is 200 MG. The rest is a matter of dividing the active-life by the dosage to decide how many milligrams of free testosterone (or simply use the dosage as a base number for less accuracy) the ester releases or disperses daily. Okay…Testosterone Cypionate has a 16 day active-life, so 200 MG/16=12.5 MG daily (including ester) or 140 MG of "actual" free testosterone released or dispersed daily. Got it? Faster acting testosterone esters such as an Acetate do "seem" to be more potent for the same reason!
Per milliliter Test 400 provides:
Testosterone Cypionate 187 MG /15-16 day active-life.
Testosterone Enanthate 188 MG/7-8 day active-life. Total MG per ML= 400 MG
Testosterone Propionate 25 MG /72 hour active-life.
*Some have stated both cypionate and enanthate have the same actual active-life. My experience with "real" products shows this to be untrue, though some underground drugs are mislabeled. As are some legit products for black market sales purposes. Go figure!
L. Rea (2002) - Chemical Muscle Enhancement Bodybuilders Desk Reference