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Generic name: miglitol (MIG li tol)
Brand name: Glyset
Dosage forms: oral tablet (100 mg; 25 mg; 50 mg)
Drug class: Alpha-glucosidase inhibitors

Medically reviewed by on Jul 30, 2021. Written by Cerner Multum.

What is miglitol?

Miglitol delays the digestion of carbohydrates (forms of sugar) in your body. This decreases the amount of sugar that passes into your blood after a meal and prevents periods of hyperglycemia (high blood sugar).

Miglitol is used together with diet and exercise to improve blood sugar control in adults with type 2 diabetes.

Miglitol may also be used for purposes not listed in this medication guide.


You should not use miglitol if you have inflammatory bowel disease (ulcerative colitis, Crohn's), a blockage in your intestines, a chronic intestinal disorder that affects digestion, or a stomach disorder that causes excess gas. Do not take miglitol if you are in a state of diabetic ketoacidosis.

Before taking this medicine

You should not use miglitol if you are allergic to it, or if you have:

  • an inflammatory bowel disease, ulcerative colitis, Crohn's disease;

  • a chronic intestinal disorder that affects your digestion;

  • blockage in your intestines;

  • a stomach disorder that causes excess gas; or

  • diabetic ketoacidosis (call your doctor for treatment with insulin).

To make sure miglitol is safe for you, tell your doctor if you have kidney disease.

Miglitol is not expected to harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using miglitol.

Miglitol can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

Do not give this medication to anyone under 18 years old without medical advice.

How should I take miglitol?

Miglitol is usually taken 3 times per day at the start of a meal. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Take each dose with the first bite of a main meal.

Low blood sugar (hypoglycemia) can happen to everyone who has diabetes. Symptoms include headache, hunger, sweating, irritability, dizziness, nausea, fast heart rate, and feeling anxious or shaky.

To quickly treat low blood sugar while you are taking miglitol, use a dextrose-based source of sugar (such as honey, dates, raisins, plums, or apricots). A sucrose-based source of sugar may not work because miglitol can inhibit the action of sucrose in the body. Sucrose-based sugar sources include cane sugar, candy, table sugar, chocolate, syrup, and non-diet soda or other sweetened foods.

Your doctor can prescribe a glucagon emergency injection kit to use in case you have severe hypoglycemia and cannot eat or drink. Be sure your family and close friends know how to give you this injection in an emergency.

Blood sugar levels can be affected by stress, illness, surgery, exercise, alcohol use, or skipping meals. Ask your doctor before changing your dose or medication schedule.

Miglitol is only part of a complete treatment program that may also include diet, exercise, weight control, regular blood sugar testing, and special medical care. Follow your doctor's instructions very closely.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take your dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking miglitol?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Miglitol side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

Common side effects may include:

  • stomach discomfort;

  • diarrhea;

  • gas; or

  • mild rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Miglitol dosing information

Usual Adult Dose for Diabetes Type 2:

Individualize dose based on efficacy and tolerability:

Initial dose: 25 mg orally 3 times a day
-After 4 to 8 weeks, may increase to 50 mg orally 3 times a day if needed; after 3 more months, may increase to 100 mg orally 3 times a day if needed based on glycosylated hemoglobin
Maintenance dose: 50 mg to 100 mg orally 3 times a day
Maximum dose: 100 mg orally 3 times a day

-Take orally at the start (with first bite) of each main meal; patients should be adhering to a diabetic diet to minimize GI side effects.
-Some patients benefit from starting at 25 mg orally once a day with subsequent titration to 3 times a day to minimize GI side effects.
-If no further reduction in postprandial glucose or HbA1c is observed with titration to 100 mg three times a day, consider lowering the dose.

Use: As an adjunct to diet and exercise to improve glycemic control in patients with type 2 diabetes mellitus.

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What other drugs will affect miglitol?

Certain digestive-enzyme supplements may decrease the effects of miglitol and should not be taken at the same time, including:

  • pancreatin (amylase, protease, lipase); or

  • products such as Arco-Lase, Cotazym, Donnazyme, Pancrease, Creon, Ku-Zyme, and others.

You may be more likely to have low blood sugar if you take miglitol with other drugs that can lower blood sugar, including insulin or other oral diabetes medications.

Tell your doctor about all your current medicines and any you start or stop using, especially:

These lists are not complete and many other medicines can increase or decrease the effects of miglitol on lowering your blood sugar. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.