Mulberry juice has a high sugar content, so should be ingested with caution by those on insulin. Mulberry juice side effects may be particularly acute in those taking cholesterol-lowering medications or from those suffering from gout, as the ingredients in the juice interact with those medications.

Persons using benzodiazepines, barbiturates, or antidepressants should drink the juice sparingly, and discontinue use if their medications seem to become less effective. There have been no systematic studies establishing either a safe or a toxic dosage of mulberry juice.

Although no scientific studies report significant mulberry juice side effects among pregnant or nursing women, elderly persons, or infants, use is discouraged as those groups tend to have underdeveloped or compromised immune functioning.

Mild diarrhea, dizziness, constipation, and bloating, may be signs of mulberry juice allergy.