Human Insulin: Uses, Types, Pros, and Cons for Diabetes Care
A scientific look at human insulin, how it works, and how it compares to insulin analogs for managing diabetes.
What to Know About Human Insulin and How It Works
Insulin is a vital hormone that regulates your blood sugar by moving glucose from the bloodstream into your body’s cells. For people with type 1 diabetes and many with advanced type 2 diabetes, administering insulin is essential to keep blood sugar within a healthy range. This article provides an in-depth overview of human insulin, covering its function, history, types, practical use, advantages, limitations, and how it compares with insulin analogs.
Understanding Insulin: Function and Importance
Insulin is produced by beta cells in the pancreas. It is released in response to rising blood sugar, typically after eating carbohydrates. Its primary role is to signal cells to absorb glucose for energy or storage, maintaining stable blood sugar levels.
If insulin production or effectiveness drops—as in diabetes—blood sugar can rise to dangerous levels, leading to complications that may affect organs and blood vessels.
- Type 1 diabetes: The body cannot produce enough insulin due to autoimmune destruction of pancreatic beta cells.
- Type 2 diabetes: The body does not use insulin effectively (insulin resistance) and may eventually make less of it.
Both types may require insulin therapy to prevent high blood sugar (hyperglycemia).
Historical Background: From Animal to Human Insulin
Before the 1980s, insulin was extracted from the pancreases of animals—primarily cows and pigs. While effective, animal insulin sometimes provoked allergic reactions and other issues due to its non-human origin.
A revolutionary step came in 1978, when scientists were able to produce synthetic human insulin using recombinant DNA technology—growing insulin proteins within specially designed E. coli bacteria. This form of insulin closely mimics what human bodies naturally produce, with far fewer risks of immune reactions.
What Is Human Insulin?
Human insulin is a laboratory-engineered version of natural insulin that has the same chemical structure as the body’s own hormone. It helped transform diabetes care by offering a safer, more consistent alternative to animal-based products.
Main Characteristics:
- Made using genetically modified microorganisms (often E. coli bacteria).
- Matches human insulin’s amino acid sequence precisely.
- Lower risk of allergic reactions compared to animal insulin.
- Divided into different types based on onset (how quickly they work) and duration (how long effects last).
Types and Brand Names of Human Insulin
Human insulin products can be categorized into regular (short-acting) and intermediate-acting forms. Each type has unique characteristics to match individual treatment needs.
What others are reading
| Insulin Type | Onset of Action | Peak Effect | Duration | Common Brands |
|---|---|---|---|---|
| Regular (Short-acting) | 15–30 min | 1–3 hours | 6–8 hours | Humulin R, Novolin R, Actrapid, Myxredlin |
| Intermediate-acting (NPH) | ~2 hours | 4–6 hours | 12–18 hours | Humulin N, Novolin N, Insulatard |
Other human insulin brand names: Actraphane, Entuzity, Insuman, Afrezza, etc.
How NPH Modifies Insulin Timing
NPH (Neutral Protamine Hagedorn) insulin is a form of human insulin to which a compound like protamine or zinc is added. This causes the insulin to be absorbed more slowly, extending both its onset and duration of action—making it suitable for background (basal) glucose control.
How Human Insulin Is Used in Diabetes Treatment
Human insulin is a cornerstone of care for people with:
- Type 1 diabetes: Insulin is required from diagnosis onward, as the body no longer produces its own insulin.
- Advanced type 2 diabetes: As insulin production wanes or resistance increases, some individuals may require insulin (alone or combined with other medications).
Modes of Administration
- Syringes: Drawing insulin from a vial for injection.
- Insulin pens: Pre-filled, portable devices for easier, more convenient dosing.
- Insulin pumps: Wearable devices that deliver steady (basal) and on-demand (bolus) insulin throughout the day. Not all forms of human insulin are pump-compatible.
- Inhalable insulin (e.g., Afrezza): A rare formulation designed for rapid absorption via the lungs.
Dosing and Combination
Doses are individualized based on blood glucose patterns, body weight, physical activity, diet, and insulin sensitivity. Human insulins can be used alone or in combination, and may be supplemented with oral anti-diabetes medications—especially in type 2 diabetes management.
How Human Insulin Differs from Insulin Analogs
While human insulin remains an effective therapy, insulin analogs—genetically engineered insulin variants—have become popular for their tailored properties.
Comparison Table: Human Insulin vs. Insulin Analogs
| Feature | Human Insulin | Insulin Analogs |
|---|---|---|
| Structure | Identical to human insulin | Modified for different absorption profiles |
| Onset of Action | Slower (short-acting: 15–30 min; NPH: 2 hr) | Ultra-rapid (minutes) to long-acting (24+ hrs) profiles |
| Peak Effect | Pronounced peak (possibility of hypoglycemia) | Some have reduced/little peak (smoother action) |
| Duration | 6–18 hrs, depending on type | Vary widely; some last up to 42 hrs |
| Cost | Generally less expensive | More expensive |
| Accessibility | Widely available | Sometimes limited by insurance/cost |
| Brands | Humulin, Novolin, Actrapid, etc. | Humalog, Novolog, Lantus, Tresiba, etc. |
Key Difference: Analogs are engineered for either more rapid absorption, slower release, or more predictable activity, aiming to reduce the risk of blood sugar extremes and offer dosing flexibility.
Benefits of Human Insulin
- Proven effectiveness: Decades of use in controlling diabetes.
- Lower cost: Typically more affordable than insulin analogs, making it accessible for many patients globally.
- Wide availability: Readily prescribed and found in pharmacies worldwide.
- Biological compatibility: Structure matches your own insulin, reducing risk of allergy.
Potential Downsides of Human Insulin
- Slower action compared to analogs: Requires dosing 30–45 minutes before meals, which can be inconvenient and lead to blood sugar lows if meals are delayed.
- Pronounced peak: Both regular and NPH forms have noticeable peaks, increasing the risk of hypoglycemia (especially if meals are skipped or delayed).
- Less dosing flexibility: Compared to some analogs, timing and meal planning can be more rigid.
- May cause variable absorption: Greater fluctuation in blood glucose compared to flatter-acting analogs.
Who Is Human Insulin Best For?
Human insulin remains a mainstay for many people with diabetes. It may be especially suitable for:
- People with stable meal patterns.
- Those seeking a lower-cost insulin option.
- Individuals who experience side effects or complications with insulin analogs.
- Situations where analogs are not available due to insurance or supply issues.
However, for some patients, especially those with unpredictable schedules, frequent hypoglycemia, or a need for flexibility, insulin analogs may be preferable.
Safety, Side Effects, and Precautions
Like all medications, human insulin may cause side effects. The most common of these include:
- Hypoglycemia (low blood sugar): Symptoms may include shakiness, sweating, irritability, rapid heart rate, and confusion.
- Allergic reactions: Rare but possible, especially at injection sites.
- Weight gain: Common with all insulins due to increased glucose uptake and storage.
- Injection site reactions: Redness, swelling, itching, or lipodystrophy (fat tissue changes).
Important Safety Tips
- Rotate injection sites to prevent tissue damage.
- Store insulin as recommended (typically refrigerated until use, then at room temperature for a limited period).
- Never use expired insulin.
- Coordinate timing of meals and insulin dosing to avoid hypoglycemia.
Frequently Asked Questions (FAQ)
What is the difference between human insulin and insulin analogs?
Human insulin is structurally identical to the body’s natural insulin, while analogs have slight modifications to alter how quickly or slowly they act. Analogs can offer faster or longer action profiles for more flexibility, but typically cost more.
Can you still get animal insulin?
Most insulin used today is human insulin or insulin analogs. Animal insulin is rarely used and may be available in special circumstances for those with allergies or resistance to other formulations.
How often do you take human insulin?
It depends on the specific type and your prescribed regimen. Some require multiple daily injections for optimal control, combining short-acting (mealtime) and intermediate-acting (basal/background) insulins.
Is human insulin as effective as insulin analogs?
Human insulin is highly effective, but insulin analogs offer some advantages in dosing flexibility and reduced risk of hypoglycemia (especially at night). Choice depends on individual needs, access, and cost.
What are the most common side effects of human insulin?
The most common side effect is hypoglycemia (low blood sugar), especially if you skip meals, exercise more than usual, or use too much insulin. Other side effects include mild allergic reactions, injection site irritation, and weight gain.
Key Takeaway
Human insulin remains a vital tool for diabetes control, providing safe, effective, and often more affordable blood sugar management. While insulin analogs offer some improvements in convenience and flexibility, human insulin continues to be accessible and lifesaving for millions of people worldwide.
References
- https://www.medicalnewstoday.com/articles/326319
- https://www.healthline.com/health/diabetes/human-insulin
- https://www.healthline.com/health/type-2-diabetes/insulin
- https://www.medicalnewstoday.com/articles/323774
- https://www.healthline.com/health/video/the-complete-guide-to-insulin-and-how-to-use-it
- https://www.healthline.com/health/video/insulin-resistance-diet
- https://my.clevelandclinic.org/health/diseases/7104-diabetes
- https://www.healthlinedme.com/Resource-Center/Medical-Health-Issues?issue=Diabetes
- https://www.news-medical.net/health/Insulins-role-in-the-human-body.aspx
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