b12 injection how long to take effect Does a Shot Last How Long Does It Take

But,some side effects can be serious

Depending on what is in the injections you receive, you could experience the following: Allergic reaction Anxiety Constipation Diarrhea Fatigue Headache Increased heart rate Insomnia Nausea Vomiting It is of note that anxiety, an increased heart rate, and insomnia typically occur only after receiving injections that contain medications like phentermine

Vitamin C should be in a separate phase or product

Within 48 hours after injection of 100 or 1000 mcg of vitamin B12, 50 to 98% of the injected dose may appear in the urine

It is injected once weekly, and the timing relative to meals does not significantly impact its effectiveness