Generic name: Insulin injection or suspension.

Other brand names: Regular — Beef Regular Iletin II, Concentrated Regular Iletin II (Pork only), Humulin, Humulin R, Novolin R, Novolin R PenFill, Pork Regular Iletin II, Regular Iletin I, Regular Insulin, Regular Purified Pork Insulin, Velosulin, Velosulin Human. Insulin Zinc Suspension (Lente ) — Humulin L, Lente Iletin I, Lente Iletin II, Lente Insulin, Lente Purified Pork Insulin, Novolin L. Insulin Zinc Suspended, Extended (Ultralente) — Humulin U Ultralente, Ultralente Iletin I, Ultralente Insulin. Insulin Zinc Suspension, Prompt (Semilente) — Semilente Iletin I, Semilente Insulin. Isophane Insulin Suspension and Insulin Injection—Humulin 70/30, Mixtard, Mixtard Human 70/30, Novolin 70/30, Novolin 70/30 PenFill. Isophane Insulin Suspension (NPH) — NPH Iletin II, Humulin N, Insulatard NPH (Human), Insulatard NPH (Pork), Novolin N, Novolin N PenFill, NPH Iletin I, NPH Insulin, NPH Purified, Pork NPH Iletin II. Protamine Zinc Insulin Suspension (PZI) — Protamine Zinc and Iletin I (Beef and Pork), Protamine Zinc and Iletin II (Beef), Protamine Zinc and Iletin II (Pork).

Insulin is an antidiabetic. It is the hormone that regulates blood sugar levels. 

Quick Facts About Insulin


Used to treat diabetes mellitus.

Insulin Dosage

Take exactly as prescribed. Always carry a food product containing sugar to counter low blood sugar symptoms. Use disposable needles and syringes or sterilize reusable ones carefully. Carefully follow dietary instructions from your doctor and take insulin as prescribed; otherwise may result in serious or fatal complications.

  • Usual adult dose: determined by individual needs.
  • Usual child dose: determined by individual needs.
  • Missed dose: follow doctor’s instructions if you miss a dose or a meal. Keep extra insulin and syringes/ needles on hand.

Insulin Side Effects

Overdose symptoms:

low blood sugar (hypoglycemia) — depressed mood, dizziness, drowsiness, fatigue, headache, hunger, inability to concentrate, irritability, nausea, nervousness, personality changes, rapid heartbeat, restlessness, sleep disturbances, slurred speech, sweating, tingling, tremor, unsteady movements. More severe symptoms — coma, disorientation, low blood pressure, pale skin, perspiration, rash over entire body, seizures, shortness of breath, shallow breathing or wheezing. If you suspect an overdose, immediately seek medical attention.

Side effects are rare; allergic reactions or low blood sugar may occur. Mild allergic reactions — swelling, itching, or redness at injection site. More serious allergic reactions — low blood pressure, pale skjn, perspiration, rash over entire body, seizures, shortness of breath, shallow breathing, wheezing. Low blood sugar symptoms: abnormal behavior; anxiety; blurred vision; depressed mood; dizziness; drowsiness; fatigue; headache; hunger; inability to concentrate; light-headedness; nausea; nervousness; personality changes; rapid heartbeat, restlessness; sleep disturbances; slurred speech; sweating; tingling in the hands, feet, lips, or tongue; tremor; unsteady movement. Severe low blood sugar symptoms — coma, disorientation. Symptoms of insufficient insulin — drowsiness, flushing, fruity breath, heavy breathing, loss of appetite, rapid pulse, thirst. Insufficient insulin may lead to loss of consciousness or death.

No known less common or rare Insulin side effects.


Inform your doctor before combining Insulin with:

anabolic steroids; appetite suppressants such as Tenuate; aspirin in large doses; beta-blockers such as Tenormin and Lopressor; diuretics such as Lasix, Dyazide, and HydroDIURIL; epinephrine (EpiPen); estrogens (Premarin); MAO inhibitors (Nardil or Parnate); nicotine products such as Nicoderm, Habitrol; phenytoin (Dilantin); steroid medications such as prednisone; thyroid medications (Synthroid or Proloid); triamterene (Dyrenium).

Do not drink alcohol unless your doctor approves use.

Special Cautions

If pregnant or planning to become pregnant inform your doctor immediately. Insulin therapy is safe for pregnant mothers, although managing the diabetes is more difficult. Does not appear in breast milk. Strictly adhere to dietary and prescribing instructions.

No special precautions apply to seniors.

Follow doctor’s instructions carefully for children.

  • Only on the instructions of your doctor should you change the Insulin type or brand of syringe or needle. Wear ID stating you are diabetic and whether or not you are Insulin dependent
  • Immediately inform your doctor if you experience nausea and vomiting; doctor should perform a urine test You should continuously monitor your glucose levels with home blood and urine testing. Immediately contact your doctor if you have above normal sugar levels with the blood test or sugar in the urine.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Insulin side effects, please contact your healthcare provider.