Humulin R and Breastfeeding
From what is known about Humulin R (regular insulin) and breastfeeding, the medication appears to be safe for breastfeeding women and their infants. Although it is not known whether Humulin R passes through breast milk, the insulin would be destroyed in the digestive tract of the infant even if it does. Before using Humulin R, breastfeeding women should ask their healthcare providers about the benefits and potential risks.
It is not clear if Humulin® R (regular insulin) passes through breast milk; however, it is not expected to cause problems when used during breastfeeding. Most healthcare providers consider Humulin R to be safe for breastfeeding women and their infants, much safer than most oral diabetes medications and possibly safer than some of the newer insulins (at least as far as breastfeeding is concerned). You should talk with your healthcare provider before taking Humulin R if you are breastfeeding or plan to start.
There is conflicting information available about whether or not insulin passes through breast milk. However, even if it does pass through breast milk, it would be destroyed in the digestive tract of the infant. Insulin (including Humulin R) is a protein that is digested and inactivated when taken by mouth. This is why insulin cannot be taken by mouth.
It should be noted that Humulin R is identical to the insulin that is produced naturally in the human body. As long as blood sugar levels are kept under control (not too high and not too low), there is no reason to expect that Humulin R would cause problems for a breastfeeding woman or her infant.
You should talk with your healthcare provider about Humulin R and breastfeeding. Each woman's situation is different, and you and your healthcare provider understand your situation best. After considering what you want and expect, as well as your current health situation, the two of you can make a shared decision about Humulin R and breastfeeding that is right for you.