Cystadane (Betaine) – Oral

What Is Cystadane?

Cystadane (betaine) is a prescription medication used to treat homocystinuria—a rare genetic disorder that causes a buildup of homocysteine in your body. 

Too much homocysteine is toxic and can lead to numerous complications. Cystadane helps lower homocysteine levels by converting it to a less harmful form.

Cystadane comes as a powder that you will need to mix with a liquid, such as water, juice, or milk, or food before taking.

Drug Facts

Generic Name: Betaine

Brand Name: Cystadane

Drug Availability: Prescription

Administration Route: Oral

Therapeutic Classification: Digestant

Available Generically: Yes

Controlled Substance: N/A

Active Ingredient: Betaine

Dosage Form: Powder for solution

What Is Cystadane Used For?

Cystadane is used to treat homocystinuria. People with homocystinuria have trouble breaking down certain amino acids (the building blocks of proteins) properly. This causes homocysteine and other toxic byproducts to build up in the body.

Symptoms of homocystinuria can vary depending on the cause. People with the most common form of homocystinuria may experience:

  • An increased risk of blood clots
  • Brittle bones (osteoporosis) that can lead to bone fractures
  • Developmental delays or learning problems
  • Nearsightedness or other eye problems

Homocystinuria may be diagnosed through newborn screening tests, although not all forms of the disease are detected with this test. Individuals with homocystinuria often develop symptoms within the first year of life, but some people with milder forms may not show signs until they are adults.

Several different gene mutations may cause homocystinuria by affecting enzymes involved in amino acid metabolism. The Food and Drug Administration (FDA) approved Cystadane to treat homocystinuria due to:

  • Cystathionine beta-synthase (CBS) deficiency
  • 5,10-methylenetetrahydrofolate reductase (MTHFR) deficiency
  • Cobalamin cofactor metabolism defect

Healthcare providers often prescribe Cystadane with vitamin B6 (pyridoxine), folic acid, or vitamin B12 (cyanocobalamin). A low protein diet may also be necessary. If you’ve been diagnosed with homocystinuria, you will need life-long treatment to keep you healthy and prevent complications. 

Cystadane (Betaine) Drug Information - Illustration by Zoe Hansen

Verywell / Zoe Hansen

How to Take Cystadane

Cystadane is typically taken twice per day, but be sure to follow the directions on your prescription. 

Cystadane is a powder that you will need to mix into a liquid or food before taking. Follow these steps to ensure you take the correct dose:

  1. Shake the bottle gently before removing the cap. 
  2. Use the measuring scoop provided with your prescription to measure your dose: One scoop equals 1 gram of Cystadane. 
  3. Mix the powder with 4–6 ounces (120–180 milliliters) of water, juice, milk, or formula until completely dissolved. You may also mix your dose in food. 
  4. Take your dose immediately after mixing. 


Cystadane should be stored at room temperature. Be sure to replace the cap on your bottle tightly to help protect the powder from moisture.

How Long Does Cystadane Take to Work?

After starting Cystadane, homocysteine levels begin to decrease within a few days, but the full effect may take up to a month. Your healthcare provider will monitor your homocysteine levels with a blood test and adjust your dose as needed.

What Are the Side Effects of Cystadane?

As with any medication, Cystadane has the potential for side effects, though it is generally well-tolerated and safe. Be aware of the following reactions, and be sure to contact your healthcare provider with any concerns.

This is not a complete list of side effects and others may occur. A medical professional can advise you on side effects. If you experience other effects, contact your pharmacist or a medical professional. You may report side effects to the FDA at or 800-FDA-1088.

Common Side Effects

Cystadane may leave a bad taste in your mouth, and some people find it difficult to take their dose because of this. It may be helpful to mix your dose into a different liquid or food until you find an option that works for you.

Other common side effects include:

  • Diarrhea 
  • Gastrointestinal problems
  • Nausea 
  • Psychological changes
  • Skin odor changes 

Other reported side effects include:

  • Dental disorders
  • Depression
  • Hair loss
  • Hives
  • Irritability
  • Loss of appetite
  • Sleep disturbances
  • Swollen tongue
  • Urinary incontinence

Severe Side Effects

Rarely, Cystadane can cause cerebral edema (swelling of the brain) and hypermethioninemia (an excess of the amino acid called methionine in the blood). Most cases occur shortly after starting Cystadane treatment or after increasing the dose.

Symptoms of cerebral edema can vary depending on which part of the brain is affected, but some signs include:

  • Changes in behavior and mental status
  • Headache
  • Lethargy
  • Nausea and vomiting
  • Seizures
  • Tiredness
  • Vision problems

Cerebral edema can cause serious complications if left untreated. Contact your healthcare provider right away if you think you are experiencing a severe side effect. Don’t hesitate to call 911 if your symptoms feel life-threatening.

Report Side Effects

Cystadane may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much of Cystadane Should I Take?

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The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (powder for solution):
    • To prevent buildup of homocysteine:
      • Adults, teenagers, and children 3 years of age and older—The starting dose is usually 3 grams taken two times a day with meals. Your doctor may adjust your dose as needed.
      • Children younger than 3 years of age—The dose is based on body weight and must be determined by your doctor. Betaine should be taken with meals.

Missed Dose 

If you miss a dose of Cystadane, take it as soon as you remember. If it’s almost time for your next dose, skip the missed dose and resume your regular dosing schedule. Don’t double up on doses.

Overdose: What Happens If I Take Too Much Cystadane?

There is no information available on the effects of a Cystadane overdose in humans. Do not take more Cystadane than prescribed by your provider.

What Happens If I Overdose on Cystadane?

If you think you or someone else may have overdosed on Cystadane, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses, has a seizure, has trouble breathing, or can’t wake up after taking too much Cystadane, call 911 immediately.


Drug Content Provided and Reviewed by IBM Micromedex®

Your doctor should check your progress at regular visits to make sure that this medicine is working properly.

What Other Medications Interact With Cystadane?

Cystadane is not expected to interact with any other medications. It’s always a good idea to keep an up-to-date list of all the medications you take—including over-the-counter products. Be sure to share this information with all your healthcare providers at every visit. 

What Medications Are Similar?

Cystadane is unique in how it works to treat homocystinuria, and there aren’t any other medications in the same class. Your provider may prescribe Cystadane with vitamin B6 (pyridoxine), folic acid, or vitamin B12 (cyanocobalamin) to help keep you healthy.

Frequently Asked Questions

  • What is Cystadane used for?

    Cystadane is used to treat homocystinuria—a condition that causes homocysteine levels to be too high. Homocysteine and its byproducts are toxic to the body.

  • How does Cystadane work?

    Cystadane lowers homocysteine levels by converting it to a less toxic substance.

  • How long does it take for Cystadane to work?

    Cystadane begins to lower homocysteine levels within a few days, but the full effect may take up to a month.

  • What are the side effects of Cystadane?

    Some people find that Cystadane leaves a bad taste in their mouth and may get nauseated. If this happens to you, try mixing Cystadane with a different recommended liquid or food until you find a combination that makes taking your dose tolerable. 

    Although rare, cerebral edema (swelling of the brain) has occurred with the use of Cystadane.

How Can I Stay Healthy While Taking Cystadane?

If you’ve been diagnosed with homocystinuria, you likely have concerns about how this condition will impact your life. Fortunately, effective treatments, including Cystadane, are available. 

Continuous, lifelong therapy is necessary to prevent complications from homocystinuria. Don’t hesitate to discuss any concerns you have with your healthcare team—especially if you’re having difficulties taking your medications as prescribed. Together, you can develop a plan that limits your symptoms and keeps you healthy.

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare professional. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Food and Drug Administration. Cystadane (betaine anhydrous for oral solution).

  3. U.S. National Library of Medicine. MedlinePlus. Homocystinuria.

  4. Morris AA, Kožich V, Santra S, et al. Guidelines for the diagnosis and management of cystathionine beta-synthase deficiency. J Inherit Metab Dis. 2017;40(1):49-74. doi:10.1007/s10545-016-9979-0

  5. Schwahn BC, Scheffner T, Stepman H, et al. Cystathionine beta synthase deficiency and brain edema associated with methionine excess under betaine supplementation: four new cases and a review of the evidence. JIMD Rep. 2020;52(1):3-10. doi:10.1002/jmd2.12092

  6. U.S. National Library of Medicine. MedlinePlus. Increased intracranial pressure.

By Christina Varvatsis, PharmD
Christina Varvatsis is a hospital pharmacist and freelance medical writer. She is passionate about helping individuals make informed healthcare choices by understanding the benefits and risks of their treatment options.