What are the possible side effects of Crystal B-12 (Cyanocobalamin)?
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Call your doctor at once if you have a serious side effect such as: chest pain feeling short of breath, even with mild exertion swelling, rapid weight gain; or unusual warmth, redness, or pain in an arm or leg Less serious side effects may include: headache, dizziness, weakness nausea, upset stomach, diarrhea numbness or tingling pain, swelling, redness, or irritation where the injection was given fever joint pain; or itching or rash This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.