Insulin
FDA ApprovedInsulin
The most well-known peptide hormone. A 51 amino acid hormone produced by the pancreas that regulates blood sugar. Multiple forms are FDA-approved. Fundamental to metabolic health research.
Dose
Highly variable, ranges from less than 0.1 U/kg to over 1.0 U/kg per day, depending on individual needs and type of insulin.
Route
SubQ injection, Inhaled, IV
Cycle
Continuous for individuals with insufficient endogenous insulin production.
Storage
Insulin is one of the few compounds here genuinely supplied as a sterile solution rather than lyophilized powder, so there is no powder stage to store — refrigerate unopened vials or pens at 2-8°C, protected from light.
What is Insulin?
Insulin is a 51-amino acid peptide hormone produced by the beta cells of the pancreatic islets. It plays a central role in the regulation of carbohydrate, fat, and protein metabolism. Its primary function is to lower blood glucose levels after meals by promoting glucose uptake into insulin-sensitive tissues (e.g., muscle, adipose tissue) via GLUT4 transporter translocation. It also inhibits hepatic glucose production, glycogenolysis, and lipolysis, while promoting glycogen synthesis, fatty acid synthesis, and protein synthesis. The peptide has two chains (A and B) linked by disulfide bonds. Multiple forms, including human insulin and various analogs with modified pharmacokinetic profiles (rapid-acting, intermediate-acting, long-acting), are widely used in research and clinical settings.
Key Benefits
- Blood glucose regulation
- Anabolic effects on muscle
- Essential for life in type 1 diabetes
- Studied for body composition at low doses
Mechanism of Action
- Insulin receptor activation
- GLUT4 transporter upregulation
- Promotes glucose uptake
- Anabolic signaling in muscle and fat
Best For
- Diabetes management
- Metabolic research
- Educational reference
Body Systems
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Molecular Information
Molecular weight
5808 Da (human insulin)
Length
51 amino acids (21 in A-chain, 30 in B-chain)
Type
Peptide Hormone
Amino acid sequence
Chain A: GIVEQCCTSICSLYQLENYCN; Chain B: FVNQHLCGSHLVEALYLVCGERGFFYTPKT
Human insulin sequence. Analogs have slight modifications to alter pharmacokinetic properties.
Pharmacokinetics
Time to peak
Highly variable depending on type of insulin: Rapid-acting (e.g., lispro, aspart): 0.5-2.5 hours; Regular (human): 2-5 hours; NPH: 4-12 hours; Long-acting (e.g., glargine, detemir): often no pronounced peak, or peak 6-8 hours.
Half-life
0.08 h
Time to clear
Highly variable depending on type; some analogs provide basal coverage for up to 24-42 hours.
Varies by specific insulin type/analog, typical endogenous insulin half-life is approximately 5-6 minutes.
Research Indications
Blood Glucose Regulation
Fundamental in research studying glucose homeostasis, diabetes mellitus (Type 1 and Type 2), and glucose clamp techniques.
Energy Metabolism
Used to investigate pathways of glucose, lipid, and protein metabolism, and their dysregulation in disease states.
Research Protocols
| Goal | Dose | Frequency | Route |
|---|---|---|---|
| Acute Glucose Lowering (Glucose Clamp Study) | Variable, often an initial bolus (e.g., 1 mU/kg/min) followed by a continuous intravenous infusion titrated to maintain target glucose levels. | Continuous IV infusion for several hours. | Intravenous (IV) |
| Metabolic Homeostasis in Diabetes Models | Adjusted to achieve target blood glucose levels, e.g., 0.1-1.0 U/kg/day, divided into multiple doses. | Multiple times daily (e.g., 2-4 times), or continuous subcutaneous infusion via pump. | Subcutaneous (SubQ) |
| Anabolic Effects (Muscle Protein Synthesis) | Low, physiological doses, often 0.05-0.1 U/kg, sometimes in conjunction with amino acid administration. | Single administration or spaced doses (e.g., pre/post-exercise). | Subcutaneous (SubQ) |
| Pharmacokinetic/Pharmacodynamic Studies of Insulin Analogs | Standardized dose, often 0.1-0.2 U/kg, or unit-based doses depending on analog. | Single administration followed by blood sampling over several hours to days. | Subcutaneous (SubQ) or Intravenous (IV) |
| Inhaled Insulin Research | Unit-based doses, e.g., 4-12 units per inhalation, adjusted to achieve post-prandial glucose control. | Pre-meal administration. | Inhaled |
Protocols for insulin research are highly individualized based on the specific type of insulin, the research objective (e.g., acute glucose clamp studies, long-term metabolic studies), and the model system (in vitro, in vivo).
Peptide Interactions
- Use Caution
Sulfonylureas
Can increase the risk of hypoglycemia when used concurrently, requiring careful dose adjustment and monitoring.
- Use Caution
Beta-blockers
May mask symptoms of hypoglycemia (e.g., tremors, palpitations) and impair recovery from hypoglycemia.
- Monitor Combination
Corticosteroids
Can increase blood glucose levels, potentially requiring higher insulin doses. Close monitoring is essential.
- Monitor Combination
Thiazide Diuretics
May elevate blood glucose, necessitating increased insulin dosage.
- Use Caution
Alcohol
Can increase the risk of hypoglycemia, particularly when consumed without food, by impairing hepatic glucose production.
- Monitor Combination
Growth Hormone
Can induce insulin resistance and elevate blood glucose, potentially requiring higher insulin doses.
How to Reconstitute
- 1Verify product integrity and expiration date.
- 2Inspect the solution for clarity and absence of particulate matter.
- 3If using a multi-dose vial, clean the rubber stopper with an alcohol swab.
- 4Draw the prescribed dose into an appropriate syringe.
- 5Administer immediately as per research protocol.
What to Expect
- Week 1-2: Initial stabilization of blood glucose levels may be observed, with careful monitoring and dose adjustments frequently discussed in research contexts.
- Week 2-4: Continued adjustments to dosing protocols are commonly needed to optimize glycemic control and study specific metabolic parameters.
- Weeks 4-8: More stable blood glucose profiles might be achieved, allowing for observation of longer-term metabolic effects depending on the research design.
- Beyond 8 weeks: Long-term studies would continue to monitor metabolic markers, body composition, and any potential adverse effects.
Side Effects & Safety
| Effect | Frequency | Severity |
|---|---|---|
| Hypoglycemia | Very Common if misused | Potentially fatal |
| Injection site lipohypertrophy | With chronic use | Moderate |
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Open CalculatorPeptides discussed here are for research purposes only. Nothing on this page is medical advice. Always consult a qualified professional before making health decisions.