I have used this 6 times at 1cc over the last 1.5 weeks. You can varify this by the level of vial(left some so you guys could see the color). This prop works great however gave me serious PIP. This PIP was not prevelant until the following day when Inject site showed bruising and swelling(small round ball). Within 3 days lump and bruising gone. Injected mostly in buttocks however tried once in mid thigh (not recommended) with this Test-prop. I also injected Eurochem Deca in oppposite mid thigh to compare reaction. The next day my thigh with T-prop felt like a horse kicked it , my knee was buckling all day, very painful. Thigh with deca only small irritation slight pain. Both legs had no bruising or bump. My body was getting used to it over the week so irritation was supsiding getting less skin reactions. I have used 3 X 10ml vials of genesis prop in the last 10 weels and never had any bruising or PIP. This could be because they use different oils/it's under dosed or hormones used are different etc. This Test-prop felt a lot stronger and I had stronger gains while using. If PIP is a indicator of strength this brand is very strong. Yes I know not all test-prop gives PIP. I will order this product again from site.