Energy Crash After B-12 Shots: A Patient's Perspective

Last fall I started talking B-12, or Cyanocobalamin, shots on a weekly basis. My doctor assured me the shots would increase my level of energy, alertness and that I would probably type faster too. With those promises, I anxiously filled my prescription and began the weekly B-12 shots.

After ten weeks of B-12 shots, I was instructed by my doctor to start administering the shot on a monthly basis, if my levels increased. Blood tests confirmed that my level of B-12 was within a safe range, but still on the low end of the scale.

I was feeling great, and didn't think twice about decreasing my dosage. My energy levels had returned to normal, with the help of the shots, and I was more productive than ever at work.

B-12 Energy Crash
I began the monthly injections, and after two months began to feel what I am calling the B-12 energy crash. Although I was still taking the shots, the lapse between shots made it seem as if I weren't taking them at all. I began to feel lethargic, exhausted and physically drained by early afternoon. I would even notice my eyes drooping, and shutting while working at my desk. My body felt like it was going through withdrawal, and was even more fatigued than before I started the B-12 shot regimen last Fall.

After weeks of trying to tell myself I was just tired from long work days and sleepless nights, I decided to call my doctor's office and speak with the nurse. After discussing my symptoms with the nurse, and my doctor, they decided to put me back on the weekly dosage of B-12 shots.

Increased Dosage
After two weeks of the increased dosage, I am still fatigued. When I initially started the B-12 shots, it took at least five weeks before I noticed a difference. I am expecting it to take a similar amount of time to build up in my body again.

If you or someone you know currently uses B-12 shots, be aware of the potential for an energy crash when the dosage or frequency changes decreases. Although it seems like a logical occurrence, I was never informed how dramatic the withdrawal could effect my body. If you plan on starting B-12 shots, ask your doctor a lot of questions before starting the regimen, including long term plans and alternate options.