I currently use both Lantus and Novolin R. At random times I experience painful burning or stinging when the insulin is being injected, but at other times I feel nothing. I keep both of my in use vials of insulin at room temperature, so it's not that I'm injecting cold insulin. My Lantus dose is 38 units, my Novolin R varies from 5 units to 15 ... More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.