I just discovered that there are diferent formulas for the Progesstrone in Oil and I've been taking the thick formula all this time. I just switched insurance companies and previously had to get my PIO from Freedom Fertility. My nurse said their PIO is made with sesame oil. It is so thick and I can feel the medication as it is going in. I needed a refill and my new insurance allows me to go to whichever pharmacy I like, so I switched to Mandell's. They make their PIO with a thinner oil. Just had my first injection with the new PIO and it was so much easier!