Tips On Humalog®
The fast insulin from Indianapolis
by John Walsh, P.A., C.D.E. and Ruth Roberts,
M.A.Copyright © 1997 by Diabetes Services, Inc.

Regular or High Octane?

Humalog is the new, fast-acting insulin that provides greater flexibility and better blood sugar control. Produced by Lilly, this insulin offers a quicker action time than Regular insulin, with both a higher peak activity and a shorter working time. Many people who've tried it report that their control is improved and that they feel better. 

Why is Humalog often better than Regular, how can you improve its effectiveness, and what does the latest clinical research reveal about this insulin? 

Humalog Compared To Regular

Like Regular, Humalog is used to cover meals and snacks. Most meals raise the blood sugar for only 2 to 3 hours after the meal. Once injected, Regular insulin takes 30 minutes to begin working, peaks between 2 and 4 hours and hangs on for 6 to 8 hours. Humalog, on the other hand, begins working in 10 minutes, peaks at 1 to 2 hours and is gone in about 3 and1/2 hours. 

The great advantage of Humalog is that it matches the "action time" for most meals. You can take Humalog as you begin eating, rather than the 30 to 45 minutes prior to eating required of Regular. No longer do you need to accurately anticipate when you (or your young child with diabetes) will begin eating. In addition, Humalog leaves your body faster so you don't have residual insulin causing low blood sugars in the late afternoon or, even worse, in the middle of the night. 

For most meals, Humalog is lowering the blood sugar at the same time the food is raising it. The rise in the blood sugar seen in the first hour after eating is much lower, and by the end of the second hour the blood sugar is often back to its starting point. Humalog's shorter action time eliminates its action well before the next meal begins, and most importantly for many, before going to bed. 

With Humalog you're better equipped to prevent spiking blood sugar between meals, while avoiding the lows that result from the combined buildup of Regular and long-acting insulins. The clearly defined action time of Humalog also makes it easier to adjust meal doses as well as long-acting insulin doses. 

Humalog is also an excellent insulin to use to lower high blood sugars. Its faster action means that less time is spent at high blood sugar levels, with less residual insulin triggering low blood sugars later. 

Techniques To Improve Humalog's Effectiveness

Test often. Test your blood sugar often to determine how Humalog works best for you. As you start using Humalog, it is wise to test before eating, 2 hours after eating, and anytime you experience unusual symptoms. Test often and use special caution when lowering high blood sugars. 

Cover food differently. The greatest contribution Humalog offers is its convenience. You take an injection with the first bite of food. No more waiting to eat for 30 to 45 minutes after injecting, which can lead to low blood sugars. Of course, with Humalog's quick action, do not delay eating! If the premeal blood sugar is high and eating is delayed to allow the blood sugar to drop, the food must be eaten as planned to avoid a low blood sugar. 

Foods with a high glycemic index that raise the blood sugar quickly, like cold cereals or a scone for breakfast, are easily covered with Humalog. However, low glycemic carbohydrates, like pasta al dente or a bean burrito, that digest slowly can present a problem. Hypoglycemia may occur before these foods completely digest. Or Humalog may cover the food during the first two hours after eating, but then the blood sugar may go high as the food continues to digest and enter the blood stream long after Humalog's action has peaked. 

As a possible solution for covering low glycemic foods, split the Humalog dose in two and take the second half of the dose an hour or two after eating. Another option is to mix Humalog with Regular to better match slow carbohydrates. 

Meals with a high fat content may also be best covered by taking Humalog after the meal is eaten to better match the slow digestion of these meals. And, of course, if your blood sugar is low or on the edge of low at mealtime, eat the meal and then take Humalog afterwards. 

Some people have noticed unexpected high blood sugars with Humalog and report that Humalog may deteriorate faster in hot weather than Regular. These contol problems could be occurring because the short and long-acting insulins are not set up correctly to cover the body's need for insulin. But, as always, test often and if your insulin does not apear to be having its full effect, try opening a new bottle. 

Treat lows differently. Because of Humalog's fast action, using fast carbs for lows becomes even more important. Fast carbs like glucose tabs, honey, candies with dextrose like Sweet Tarts work best. Low blood sugars experienced on Humalog usually occur within 3 hours of the injection. If the blood sugar goes low 3 or more hours after the injection, only a small amount of carbohydrate, usually 10 to 15 grams, is needed to remedy the situation. 

Another great benefit of Humalog is that it has been shown to decrease the chance of a low during the night. With Regular, many people find they have nighttime lows because its extended action time is several hours longer than the digestion time for most foods. They often need a bedtime snack when using Regular to avoid a low during the night. In contrast, Humalog can be used at dinner with less need for a bedtime snack. 

Use Short and Long-acting Insulins Differently.

Many people on multiple injection programs use a single injection of long-acting insulin at bedtime, and then use Regular insulin before each meal. When Regular is used to cover meals, its long action time lets it work almost as a background insulin to cover much of the day. But if Humalog is used with only a dose of long-acting insulin at bedtime, insulin levels often drop too low during the day. Humalog often disappears before the next meal is eaten, and the blood sugars will often rise between meals as the insulin level drops before the next Humalog dose is taken. Generally at least two injections of a long-acting insulin are needed on Humalog. 

Even when a long-acting insulin is taken at breakfast and bedtime with Humalog, some people find their blood sugar rises near bedtime or at bedtime. Because no dinner Regular is covering the early nighttime hours, they need to add some long-acting insulin at dinner to keep the blood sugar from rising after dinner when the dinner Humalog has disappeared, the morning long-acting insulin is no longer active, and the bedtime insulin has not begun to work. 

One current trend is to use smaller, more frequent doses of long-acting insulin for a more stable background level of insulin through the day. Either Lente, Ultralente, or NPH can be used depending on their effectiveness for a particular person. Some people use two injections, but many are going to three injections a day. One research study from Italy reported at the 1997 ADA meeting in Boston found that NPH added to Humalog at all 3 meals produced good results. 

Many research studies have reported that insulin doses remain the same when people switch from Regular to Humalog. However, there are several reasons to be alert for changes in insulin doses. Because meals are covered more precisely with Humalog, look for less insulin needed for meals. Because Humalog has less action time between meals than Regular, with Humalog there may be more need for long-acting insulin during the day.

In research on Humalog's biologic activity, two of six studies found that Humalog was as much as 10% more effective than Regular in lowering blood sugars, while the other four found its activity was identical to Regular. So be alert if a unit of Humalog seems to go farther. Any change in insulin doses should only be attempted after discussing them thoroughly with your physician and testing during the night to see their effect. 

Pump differently. Because Humalog controls blood sugars better than Regular, some pumpers report needing less overall insulin. Boluses may need to be reduced by as much as 20 to 30%. Basal rate amounts generally don't change, although some find they need to raise the basal rate in the late evening and early nighttime hours because the action of the bolus of Regular taken for dinner is no longer working into the nighttime hours. With Humalog's greater speed, any basal rate changes will be made closer to the actual time they are needed. For instance, on Regular, if the basal rate is raised at 2 a.m. to offset a Dawn Phenomenon, this rise is typically delayed until 3 a.m. or 4 a.m. on Humalog. 

For safety's sake, do not use the suspend feature with Humalog for exercise or low blood sugars. Because of its short action time, insulin levels typically drop within 60 to 90 minutes, followed by rising blood sugars. For the same reason, take Humalog by injection at the FIRST high blood sugar reading over 300 mg/dl (17 mmol). If any delivery problem occurs with Humalog in your pump, blood sugars can begin to rise as early as 60 to 90 minutes later, and ketoacidosis could start within 4 to 5 hours. 

Clinical Research Results

Results from 23 clinical research studies using Lispro (Humalog) in Europe, Canada and the United States were reported at the yearly American Diabetes Association meeting in Boston in June, 1997. Our analysis of these studies found positive results in four areas when comparing Humalog with Regular: 



Humalog gives better readings 1 to 2 hours after meals.Usually Humalog was given at the start of a meal,but even when taken 15 minutes after a meal Humalog gives better postmeal readings compared to Regular taken 40 minutes before a meal.


Blood sugars are improved through the entire day due largely to improved readings after meals.


The HbA1c is lowered by an average of 0.5%. 


Humalog improves quality of life.


Other results in individual studies were also positive. In one study, two people who had hypoglycemia unawareness regained warning symptoms of a low blood sugar. In a study of adolescents, incidents of nighttime hypoglycemia decreased. 

No change in the total daily dose of short and long-acting insulin was required to attain better control, and no change in the incidents of hypoglycemia resulted from lowering overall blood sugars. (But be aware of our cautions about the possible need to alter doses, as mentioned earlier.) 

The subjects in most studies were Type 1's on long term intensive management who had good control with HbA1c's in the 7's or 8's before using Humalog in the study. But one study followed people with "brittle diabetes" with erratic blood sugars and high HbA1c's. On switching to Humalog from Regular, their diabetes improved in all four areas listed above. Another study using people with Type II diabetes also reported these improvements and the subjects had no weight gain. 

Two recent studies used Humalog in insulin pumps, one with 39 people and the other with 113. Results were again similar to those mentioned above. No changes were noted in the frequency of hypoglycemia, in infusion line clogs, or in other adverse events. 

In summary, the majority of people who have tried Humalog have chosen to stay on it. Most have been impressed by improvements in their control and in the convenience of taking their insulin when they eat. 


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