Inhaled insulin is a newer, needle-free option that helps people with diabetes manage their blood sugar. Like many treatments, it comes with questions and misconceptions. Some people worry about how it works, who can take it or whether it’s safe for the lungs.
Research and patient education resources show that while there are real considerations — like avoiding use for people with certain lung conditions — many concerns are based on myths rather than evidence. For example, current studies haven’t found a clear link between today’s inhaled insulin and cancer, and it’s generally well tolerated when used appropriately.
This article aims to help you better understand inhaled insulin and how it may fit into care — especially for people living with cancer and diabetes — by covering:
- What is inhaled insulin?
- Does inhaled insulin cause lung cancer?
- What to ask your doctor about inhaled insulin
- Why injectable insulin and medications remain the standard of care
- How City of Hope is accelerating advancements in diabetes and cancer
What Is Inhaled Insulin?
Inhaled insulin is a rapid-acting form of insulin that you breathe in through your lungs instead of injecting with a needle. Today, the only inhaled insulin approved by the U.S. Food and Drug Administration is Afrezza®, which is used to help adults with type 1 or type 2 diabetes manage blood sugar levels, especially around mealtimes.
Afrezza comes as a dry powder that you breathe in using a small inhaler device. The insulin travels quickly through the lungs and into the bloodstream, where it begins lowering blood sugar within minutes. Because it works so quickly, it’s considered an “ultra rapid-acting” insulin, helping control the rise in blood sugar that happens after eating.
For some patients, inhaled insulin offers a more effective, convenient option without injections. But like any treatment, it isn’t right for everyone, and it should always be used under the guidance of a healthcare provider.
Does Inhaled Insulin Cause Lung Cancer?
One of the most common misconceptions people hear about inhaled insulin is that it causes lung cancer. This idea largely comes from early studies of older inhaled insulin products like Exubera®, where a small number of lung cancer cases were reported, raising understandable questions.
Here’s what we know today:
Current evidence doesn’t show a clear or proven increase in lung cancer risk with modern inhaled insulin (Afrezza), but research is ongoing and doctors recommend caution for some patients. That’s why regulators and clinicians still monitor this closely.
Inhaled insulin has now been studied in thousands of patients, and the most reliable research is reassuring. For example:
- A large pooled analysis of 13 clinical trials involving more than 5,000 people found that rates of lung cancer were similar between those using inhaled insulin and those using other treatments, with no clear increase in risk
- A more recent 2024 review of clinical data also concluded that there’s no established link between inhaled insulin and cancer, while still recommending ongoing monitoring as more long-term data become available
Because early studies raised questions — and because lung cancer may take many years to develop — doctors take a careful approach. This includes:
- Avoiding inhaled insulin in people who currently smoke or recently quit
- Not using it in patients with chronic lung diseases like asthma or chronic obstructive pulmonary disease (COPD)
- Monitoring lung function before and during treatment
What to Ask Your Doctor About Inhaled Insulin
If you’re considering inhaled insulin, it’s important to have an informed conversation with your care team.
“Inhaled insulin can be a good option for some patients, but it isn’t right for everyone,” explains Ping H. Wang, M.D., an endocrinologist and chair of the Department of Diabetes, Endocrinology & Metabolism at City of Hope®. “It’s important that your diabetes and cancer care are working together safely.”
Here are some helpful questions to guide a discussion with your doctor or oncologist.
Is inhaled insulin safe for me based on my lung health? Dr. Wang says: “Your healthcare provider should perform lung function tests, known as spirometry, before starting treatment and monitor you over time to make sure your lungs are healthy enough for inhaled insulin.”
How would inhaled insulin fit into my current diabetes care plan? Inhaled insulin is a fast-acting (bolus) insulin, meaning it’s used to control blood sugar spikes when you eat. It’s not a replacement for long-acting (basal) insulin, which helps keep blood sugar steady between meals and overnight.
Will I still need other types of insulin? Many people, especially those with type 1 diabetes, still need a separate, longer-acting insulin (basal) along with inhaled insulin to maintain overall blood sugar control.
Are there any reasons I shouldn’t use inhaled insulin? Afrezza isn’t recommended if you have asthma, COPD or other chronic lung conditions. It’s also not for people who smoke or recently quit smoking.
How could my cancer treatment affect my blood sugar or insulin needs? “Chemotherapy and other medications used during cancer treatment, such as steroids, can affect how your body handles blood sugar and may even contribute to diabetes,” Dr. Wang says. “Your diabetes monitoring and management plan may need adjustments.”
What are potential side effects? Some people experience low blood sugar (hypoglycemia), mild cough or throat irritation when using inhaled insulin. Your care team will explain what’s expected and when to report a side effect.
Why Injectable Insulin and Medications Remain the Standard of Care
For cancer patients with diabetes, inhaled insulin isn’t regarded as a first-line treatment. Instead, it’s considered an alternative option in select situations. This is because inhaled insulin has limitations. For instance, it doesn’t allow for the same level of precise dosing as injectable insulin, and only moderate amounts may be delivered at a time. Many cancer patients require higher or more flexible insulin dosing, which inhaled devices may not be able to provide.
In addition, inhaled insulin works through the lungs, so experts recommend avoiding it for people with underlying lung conditions or increased lung-related risks. For example, it’s not recommended for individuals who smoke or have chronic lung diseases like asthma or COPD, as these conditions can affect how the medication is absorbed and may increase the risk of side effects.
For these reasons, the primary diabetes management options for cancer patients include:
- Insulin delivered by injection or through an automated insulin pump (artificial pancreas)
- Non-insulin medications (depending on the type of diabetes and overall health)
Because these options allow for more precise dosing and don’t rely on lung function, they are generally the preferred and safest choice — especially for patients with complex medical needs.
“While medications like insulin are critical tools, they work best when paired with a strong foundation of healthy eating and daily habits,” emphasizes Dr. Wang. “Diet and lifestyle changes are essential to managing diabetes — we can’t rely on medication alone.”
City of Hope: Accelerating Advancements in Care
As research continues to evolve, City of Hope is leading the way at the intersection of diabetes and cancer research and care — from inventing the technology behind human synthetic insulin to driving innovation forward through clinical trials and new therapeutic approaches.
Today, through initiatives like the Wanek Family Project, researchers are developing next-generation therapies aimed at improving how diabetes is treated.
“At City of Hope, we’re investigating the root cause of diabetes among cancer patients and developing new technologies to improve diabetes management for this population,” adds Dr. Wang.