Whether they have Type 1 diabetes, Type 2 diabetes, or gestational diabetes, millions of Americans with diabetes take insulin on a regular basis. For diabetics, insulins such as Humalog and Novolog are essential for controlling blood sugar levels. But what’s the difference between these insulin products?
Diabetes is not a curable condition, but it can be managed with treatment and lifestyle changes. According to the Centers for Disease Control and Prevention (CDC), normal fasting blood sugar is under 99 mg/dL, whereas fasting diabetic blood sugar level is higher than 126 mg/dL. It is important to regularly screen blood glucose levels during check-ups with your doctor to monitor whether you are at risk for diabetes. Type 1 diabetes is usually diagnosed early during youth so it is also called juvenile diabetes.
Type 2 diabetes can be diagnosed at any age, although it is more common in adults. A blood sugar level between 100-125 mg/dL can indicate prediabetes, and with certain lifestyle changes, it can be prevented from developing into type 2 diabetes. Since in both type 1 and 2 diabetes the body cannot make insulin itself, diabetic patients have to take artificial insulin for the rest of their lives.
Insulin
Insulin is a hormone produced by the pancreas that regulates blood sugar levels. It allows cells in the body to absorb glucose from the bloodstream, where it’s used for energy or stored for future use. Insulin plays a critical role in metabolism by facilitating the uptake of nutrients into cells, inhibiting the production of glucose by the liver, and promoting the storage of excess glucose as glycogen or fat. Insufficient insulin production or ineffective insulin use leads to high blood sugar levels (hyperglycemia), a hallmark of diabetes mellitus. Managing insulin levels is essential for maintaining normal metabolism and preventing complications associated with diabetes.
How Insulin Works
Insulin regulates blood sugar levels by facilitating the uptake of glucose into cells from the bloodstream. Released by the pancreas in response to elevated blood glucose levels after meals, insulin promotes the storage of excess glucose as glycogen in the liver and muscles, lowering blood glucose concentrations. It also inhibits the liver’s production of glucose and enhances cellular uptake of amino acids for protein synthesis, while promoting the storage of fats as triglycerides in adipose tissue. In diabetes, insufficient insulin production (Type 1) or reduced sensitivity to insulin (Type 2) leads to chronically high blood glucose levels, requiring management through medication, diet, and lifestyle changes to mitigate health risks associated with hyperglycemia.
Type of Insulin
There are several types of insulin, each with different characteristics and durations of action:
- Rapid-Acting Insulin
- Begins to work within 10-15 minutes after injection.
- Peaks in about 1-2 hours.
- Examples: Insulin lispro (Humalog), insulin aspart (Novolog).
- Short-Acting Insulin
- Takes effect within 30 minutes to an hour.
- Peaks in 2-4 hours.
- Examples: Regular insulin (Humulin R, Novolin R).
- Intermediate-Acting Insulin
- Onset is 1-2 hours after injection.
- Peaks in 4-12 hours.
- Examples: NPH insulin (Humulin N, Novolin N).
- Long-Acting Insulin
- Provides a steady level of insulin over a longer period.
- Generally lasts 18-24 hours or longer.
- Examples: Insulin glargine (Lantus), insulin detemir (Levemir), insulin degludec (Tresiba).
- Ultra-Long-Acting Insulin
- Provides a basal insulin level for more than 24 hours.
- Examples: Insulin degludec (Tresiba), and insulin glargine U-300 (Toujeo).
Humalog and Novolog: What’s The Difference?
Humalog is a rapid-acting insulin that received FDA approval in 1996. It mimics human insulin and has a similar chemical structure. Known by its generic name, insulin lispro, Humalog is available as a subcutaneous injection solution.
Humalog comes in 10 mL and 3 mL multi-dose vials, as well as 3 mL cartridges and pre-filled pens (Humalog KwikPen, Humalog Tempo Pen, Humalog Junior KwikPen). All Humalog formulations contain 100 units/mL (U-100) of insulin, except for the Humalog KwikPen, which also comes in a 200 units/mL (U-200) version.
Novolog, another rapid-acting insulin analog, is known by its generic name, insulin aspart. It is chemically similar to human insulin, with aspartic acid replacing a proline amino acid in its structure. Novolog was FDA approved in 2000.
Similar to Humalog, Novolog is available in a 10 mL multi-dose vial for use with a syringe. Novolog also comes in 3 mL cartridges (PenFill cartridges) and pre-filled pens (Novolog FlexPen, Novolog FlexTouch), all containing 100 units/mL of insulin aspart.
Which Is More Effective, Novolog or Humalog?
Humalog and Novolog are both fast-acting insulins that provide effective blood sugar control when administered correctly. These insulins are injected into the abdominal area, thighs, upper arms, or buttocks and are equally effective at lowering blood sugar levels.
While both insulins act quickly, Novolog has a slightly faster onset. Novolog can be injected within 5 to 10 minutes before a meal, whereas Humalog should be injected within 15 minutes before eating.
Compared to other types of insulin, rapid-acting insulins like Humalog and Novolog are often better for controlling glucose levels around mealtimes. Rapid-acting insulin is more effective than regular insulin for managing blood sugar levels at mealtimes in people with Type 1 diabetes. The study also found that rapid-acting insulins are more effective at improving HbA1c levels in individuals with Type 1 diabetes.
The choice between Humalog, Novolog, or another type of insulin depends on individual health conditions. It is important to consult a healthcare provider to determine the best insulin option for your needs.
Common Side Effects of Humalog vs. Novolog
Both Humalog (insulin lispro) and Novolog (insulin aspart) share similar side effects due to their rapid-acting nature and use in managing blood sugar levels. Here are the common side effects for both:
Humalog Side Effects
Humalog can cause hypoglycemia (low blood sugar), which manifests with symptoms such as shakiness, dizziness, sweating, hunger, irritability, headache, and rapid heartbeat. Injection site reactions are also common, including redness, swelling, itching, or pain at the site of the injection. Some users may experience weight gain over time. Allergic reactions, although rare, can occur and may present as rash, itching, swelling, severe dizziness, and trouble breathing. Additionally, Humalog may cause lipodystrophy, which involves changes in fat tissue at the injection sites, either as fat accumulation (lipohypertrophy) or loss (lipoatrophy).
Novolog Side Effects
Novolog shares many of the same side effects as Humalog. Hypoglycemia is a primary concern, with similar symptoms such as shakiness, dizziness, sweating, hunger, irritability, headache, and rapid heartbeat. Injection site reactions like redness, swelling, itching, or pain are also common. Users might experience weight gain over time. Allergic reactions, though rare, can include rash, itching, swelling, severe dizziness, and trouble breathing. Novolog can also lead to lipodystrophy, causing either fat accumulation or loss at the injection sites.
Additional Potential Side Effects
Both Humalog and Novolog can cause skin thickening or pits at the injection site. Peripheral edema, which is swelling of the hands and feet, may occur. Over time, some patients may develop insulin resistance, where the body’s response to insulin diminishes.
Drug Interactions Between Novolog and Humalog
Both Novolog (insulin aspart) and Humalog (insulin lispro) can interact with other medications, which can affect their efficacy and safety. Patients must be aware of these interactions to manage their diabetes effectively and avoid complications. Here are some key drug interactions for both insulins:
Other Antidiabetic Agents
- Medications like glipizide, glyburide, and repaglinide can increase the risk of hypoglycemia when used with Novolog or Humalog.
- These medications can be used together with rapid-acting insulins, but close monitoring is necessary to avoid hypoglycemia.
Beta-Blockers
- Beta-blockers, such as propranolol and metoprolol, can mask the symptoms of hypoglycemia, making it harder for patients to recognize low blood sugar levels. They can also affect blood sugar levels directly, leading to either hyperglycemia or hypoglycemia.
ACE Inhibitors and Angiotensin II Receptor Blockers (ARBs)
- Medications like lisinopril (an ACE inhibitor) and losartan (an ARB) can enhance the glucose-lowering effects of Novolog and Humalog, increasing the risk of hypoglycemia.
Diuretics
- Thiazide diuretics, such as hydrochlorothiazide, can raise blood sugar levels, potentially requiring an adjustment in the dosage of Novolog or Humalog.
Corticosteroids
- Corticosteroids like prednisone can increase blood sugar levels, potentially necessitating higher doses of Novolog or Humalog.
Hormonal Contraceptives
- Some hormonal contraceptives can affect blood sugar levels, requiring adjustments in insulin dosing.
Monoamine Oxidase Inhibitors (MAOIs)
- MAOIs, such as phenelzine, can enhance the hypoglycemic effect of insulin, increasing the risk of low blood sugar.
Thyroid Medications
- Thyroid hormones like levothyroxine can affect blood sugar control, potentially requiring adjustments in insulin dosage.
Final Thought
Humalog (insulin lispro) and Novolog (insulin aspart) are both rapid-acting insulins used to manage blood sugar levels in people with diabetes. While they share many similarities, including their effectiveness in lowering blood sugar levels, onset, and duration of action, there are some key differences. Novolog has a slightly faster onset than Humalog, making it suitable for injection closer to mealtime. Both insulins have similar side effect profiles and can interact with a range of medications, necessitating careful management under a healthcare provider’s guidance.
Ultimately, the choice between Humalog and Novolog depends on individual health needs, response to the insulin, and insurance coverage. Consulting with a healthcare provider will help determine the most suitable insulin for your diabetes management.
For convenience, you can purchase Humalog or Novolog from USA Script Helpers, a trusted pharmacy partner.
