Let's take a minute to talk about your medication.

This is cyanocobalamin, which is more commonly known as Vitamin B12. There are 1,000 micrograms per 1 milliliter. This medicine is given to people who can't absorb enough vitamin B12 from foods. 

You should inject your dose only as directed by your doctor. The doctor will tell you if you should give it 'subcutaneously' which is under the skin, or 'intramuscularly' which is in the muscle. 
Before injecting it at home, you should demonstrate an injection to your health care provider, so you feel confident doing it on your own. You should also know how to dispose of needles. If you have questions, your doctor or pharmacist can help. 

This medicine is usually very well-tolerated.  Still, some side effects can occur, like itching, diarrhea or a short-lived rash. These effects are normal if they are mild and should go away.  If these or other side effects become reasons you want to stop taking this medicine, please talk to your doctor or pharmacist. But, don't stop taking it, unless your doctor says it's okay.

As with any medicine, rare but serious side effects can occur. You should call your doctor right away if you notice any unusual changes to your body, like swelling or shortness of breath. Also call if the injection site ever seems irritated, like if it feels hot or painful.

For best results, plan ahead for refills, and follow your doctor's advice for other vitamins that may help your condition.