The CDC keeps pretty good stats, as of 2011, there were about 6 million diabetics taking insulin;<p><a href="http:&#x2F;&#x2F;www.cdc.gov&#x2F;diabetes&#x2F;statistics&#x2F;meduse&#x2F;fig1.htm" rel="nofollow">http:&#x2F;&#x2F;www.cdc.gov&#x2F;diabetes&#x2F;statistics&#x2F;meduse&#x2F;fig1.htm</a>