Nat Jeffries' Blog

This summer I got the chance to try a sample pack of the inhalable insulin Afrezza. Afrezza claims to be “the only ultra rapid-acting inhaled insulin that starts lowering blood sugars in ~12 minutes for adults living with type 1 or type 2 diabetes”. It is able to act so rapidly because it’s absorbed straight into the bloodstream from the lungs, whereas insulin is typically infused into subcutaneous fat and takes much longer to reach the bloodstream.

There are two key benefits to this rapid acting insulin; it starts acting quickly and it clears the system fast. Rapid action means that I’m no longer waiting for hours to see if I sized my meal dose or correction accurately. It also means that I can counteract high glycemic index foods effectively with little or no postprandial hyperglycemia. Quick clearing means that I’m no longer experiencing hypoglycemia hours after a correction or meal bolus. Also, it makes managing my blood glucose during exercise easier since I have little or no insulin on board hours after my last meal. Previously, the only time I reliably had only basal insulin on board was before breakfast. Now if i eat lunch at 1pm and run at 3pm it’s like running in the morning except that I have fuel on board – a real game changer that I haven’t heard other Afrezza users mention.

I have been using Afrezza for many meal boluses and leaving background basal rates up to my pump since November 2025.

There are a few potential drawbacks to using Afrezza. Most importantly are lung related side-effects. During the clinical trials for Afrezza’s approval some users had decreased lung function and there was a non-statistically-significant increase in lung cancer risk. With the information available now, I feel the improvement in my glycemic control and the increased ability to exercise without experiencing hypoglycemia makes the tradeoff worth it, but as more information comes out this could change. I’ve personally not experienced any side effects yet during my six months of use. Another, admittedly smaller, drawback is that I no longer have all insulin dosing information available to me on my pump. This will make it harder for me to effectively share data with my endocrinologist, and to collect data for my own research. Afrezza’s 4-unit dosing may seem limiting, but since carb estimates are often inaccurate and insulin sensitivity changes, simpler dosing could be beneficial. Finally, Afrezza can be expensive. I am lucky that my endo is experienced prescribing Afrezza, and that the inexpensive private insurance plan I use covers Afrezza with an out-of-pocket of only $35/month. According to Mannkind’s website, around 70% of private plans cover Afrezza for T1D.

Make sure to only use Afrezza on relatively fast-acting meals and be cautious with dosing. I’ve had 8 or 12 units of Afrezza send me low quickly when I have a low GI breakfast like eggs on toast. Afrezza has the potential to send you low faster than regular insulin, and it’s not always possible to out-eat like it typically is with other insulins.

I’ve found that Afrezza improves my glycemic control. I can recover more quickly from missed boluses, fully dose for meals before exercise and avoid post meal spikes. I’d recommend it to anybody who wants to improve control, especially athletes.