Well, I have had two vials of 20ml. It works great the problem is that it is very tempermental. It is very thick and it separates too easily even after warming it up under warm water. The separation is a problem because by the time u get the pin in the suspension is already separating from the water. I tried drawing with an 18 gauge pin and inject with 20 but it gets clogged too easily. Now I just inject with 18 and after I have pushed the pin in I flick the syringe a few times to mix it up and this method has been the best. I may never go with supra again just because of the hassle, plus I don't like anything thicker than 20 gauge. Like I said though the results are great when you actually get it in you.