It's wouldn't go anywhere, you're not going to get it done with a 28g pin - simple as that. Even with 6% bodyfat (back in the day) I still had to do a 25g minimum.
The needle would be in your ass for an hour with that size. 2 hours to draw it out of the vial. 23g is perfect, if its still running to slow for your comfort heat up the test.