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Betaine Side Effects

Medically reviewed by Last updated on Jan 3, 2023.

Applies to betaine: oral powder for solution, oral tablet.

Serious side effects of Betaine

Along with its needed effects, betaine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Other side effects of Betaine

Some side effects of betaine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

Betaine may cause a body odor. Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

For Healthcare Professionals

Applies to betaine: compounding powder, oral powder for reconstitution.


Common (1% to 10%): Nausea, gastrointestinal distress

Uncommon (0.1% to 1%): Diarrhea

Postmarketing reports: Dental disorders, glossitis, stomach discomfort, vomiting[Ref]

Nervous system

Postmarketing reports: Cerebral edema[Ref]

Severe cerebral edema and hypermethioninemia have occurred with 2 weeks to 6 months of starting therapy, with complete recovery after discontinuation. All patients had cystathionine beta-synthase (CBS) deficiency with hypermethioninemia and severe plasma methionine elevations (1000 to 3000 micromol/L). The mechanism of action is postulated as secondary hypermethioninemia due to betaine therapy.[Ref]


Uncommon (0.1% to 1%): "Bad taste", "caused odor", questionable psychological changes, "aspirated the powder"

Postmarketing reports: Severe elevation in plasma methionine[Ref]


Postmarketing reports: Agitation, depression, irritability, personality disorder, sleep disturbed[Ref]


Postmarketing reports: Hair loss, hives, skin odor abnormality[Ref]


Postmarketing reports: Anorexia[Ref]


Postmarketing reports: Urinary incontinence[Ref]


1. "Product Information. Cystadane (betaine)." Recordati Rare Diseases Inc (2018):

Further information

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

Some side effects may not be reported. You may report them to the FDA.