I taken 450mg blends before in the glute once a week, no problem. I like primo and decided to try the 200mg concentrated blend. I pinced a nerve so couldn't self inject in the glute, so I starting injecting in the upper thigh around the Rectus Femoris I would say. First week I started off with 400mg of Primo and 200 of Test Cyp everything was fine, but leg was very swollen and felt a bruise like pain. The next week I jumped up to the same 200mg of Cyp but 800mg of Primo 2cc on Monday and 2cc on Wednesday. I was sick as a dog and laying in bed all weekend. I had a fever, tren cough it was horrible. In addition my thigh had a huge knot and felt like I it got hit by a baseball bat. The next week I oviously decided to being it back down to 400mg but my thigh still felt bruised so I injected 1cc between both shoulders and 1cc in my tricep. My arm blew up. I could not straighten my arm. I could not work out. Now it looked like I got hit in the arm with a baseball ball. It was like that for over a week. I contacted the manufacturer and he said any high concentrated oils and blends should only inject into the glue muscle and start off with 1/2 a cc to see how your body reacts to it. He said the high concentration in the oils makes it harder for the body to brake it down and some people get bad reactions from it. I think im done with high concentrations oils after that experience, but I hope this helps one of you guys from going through what I did. Remeber start small 1/2 cc and work your way up. Always in the glute or large muscle of the body.