Generic name: bromocriptine
Drug classes: Dopaminergic antiparkinsonism agents, Prolactin inhibitors

Medically reviewed by  A Ras MD.

What is Cycloset?

Cycloset is a prescription medicine that is used lower blood sugar in patients with high blood sugar (diabetes).

Cycloset may be given to you for other reasons. Talk to your doctor.


CYCLOSET Tablets contain micronized bromocriptine mesylate, an ergot derivative. Bromocriptine mesylate is chemically designated [Ergotaman-3′,6′,18-trione, 2-bromo-12′-hydroxy-2′-(1-methylethyl)-5′-(2-methylpropyl)-, monomethanesulfonate (salt), (5’α)-]. CYCLOSET is a single enantiomer with absolute configuration 5R, 8R, 2′R, 5′S, 11′S, 12′S.

The structural formula of bromocriptine is shown below:

Chemical Structure

Bromocriptine mesylate in CYCLOSET is a white or slightly colored micronized crystalline powder with a molecular formula of C32H40BrN5O5∙CH4SO3 and a molecular weight of 750.72. CYCLOSET Tablets contain bromocriptine mesylate USP in an amount equivalent to 0.8 mg. of bromocriptine. Each tablet contains the following inactive ingredients: lactose, corn starch, magnesium stearate, colloidal silicon dioxide, and citric acid.

Mechanism of Action

CYCLOSET contains bromocriptine mesylate, a sympatholytic, dopamine D2 receptor agonist. In patients with type 2 diabetes, timed morning administration of CYCLOSET is associated with increased insulin sensitivity and glucose disposal and reduced fasting and postprandial hyperglycemia throughout the meals of the day without raising plasma insulin levels.


Before taking Cycloset, tell your doctor:

  • If you are allergic to Cycloset; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
  • If you have high blood pressure.
  • If you have a rare hereditary problem of galactose intolerance, Lapp lactase deficiency, or glucose-galactose malabsorption.
  • If you take any drugs (prescription or OTC, natural products, vitamins) that must not be taken with Cycloset, like certain drugs that are used for mental or mood problems, migraines, or stomach or bowel problems. There are many drugs that must not be taken with Cycloset.
  • If you are pregnant or plan to get pregnant.
  • If you have just had a baby.
  • If you are breast-feeding. Do not breast-feed while you take Cycloset.
  • If you have fainting headaches.
  • If you have mental illness.
  • If you have any of these health problems: Acidic blood problem or type 1 diabetes.

This is not a list of all drugs or health problems that interact with this medicine.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take Cycloset with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Cycloset?

  • Tell all of your health care providers that you take Cycloset. This includes your doctors, nurses, pharmacists, and dentists.
  • Avoid driving and doing other tasks or actions that call for you to be alert until you see how Cycloset affects you.
  • If you have ever felt sleepy or have fallen asleep all of a sudden when taking Cycloset, avoid doing tasks or actions that may not be safe for you or others if you pass out. These are driving, climbing, and swimming.
  • To lower the chance of feeling dizzy or passing out, rise slowly if you have been sitting or lying down. Be careful going up and down stairs.
  • Talk with your doctor before you drink alcohol.
  • Check your blood pressure as you have been told.
  • Have blood work checked as you have been told by the doctor. Talk with the doctor.
  • If you have been taking Cycloset for many weeks, talk with your doctor before stopping. You may want to slowly stop Cycloset.
  • It may be harder to control blood sugar during times of stress such as fever, infection, injury, or surgery. A change in physical activity, exercise, or diet may also affect blood sugar.
  • Follow the diet and workout plan that your doctor told you about.
  • Check your blood sugar as you have been told by your doctor.

How is Cycloset best taken?

Use Cycloset as ordered by your doctor. Read all information given to you. Follow all instructions closely.

  • Take with food to prevent an upset stomach.
  • Keep taking Cycloset as you have been told by your doctor or other health care provider, even if you feel well.
  • Take within 2 hours of waking up.

What do I do if I miss a dose?

  • If you miss a dose, wait until the next day to take your normal dose.
  • Do not take 2 doses at the same time or extra doses.

What are the side effects of Cycloset that I need to call my doctor about immediately?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Signs of high or low blood pressure like very bad headache or dizziness, passing out, or change in eyesight.
  • Mental, mood, or behavior changes that are new or worse.
  • Low blood sugar can happen. The chance may be raised when Cycloset is used with other drugs for diabetes. Signs may be dizziness, headache, feeling sleepy or weak, shaking, fast heartbeat, confusion, hunger, or sweating. Call your doctor right away if you have any of these signs. Follow what you have been told to do for low blood sugar. This may include taking glucose tablets, liquid glucose, or some fruit juices.

What are some other side effects of Cycloset?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Headache.
  • Upset stomach or throwing up.
  • Constipation.
  • Feeling dizzy, sleepy, tired, or weak.
  • Runny or stuffy nose.
  • Diarrhea.
  • Not hungry.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at

If overdose is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Cycloset?

  • Store at room temperature protected from light. Store in a dry place. Do not store in a bathroom.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.




  • NDC 68012-258-21
    bromocriptine mesylate tablets
  • 0.8 mg
  • 21 Tablets
    Rx only
  • Professional Samples –
    Not For Sale
PRINCIPAL DISPLAY PANEL - 0.8 mg Tablet Bottle Label
Imprint C 9 - Cycloset 0.8 mg