Seeing Red: Do B12 Injections Work?

Sometimes it seems like everyone is fighting fatigue with vitamin B12 injections. But do they do any good?


Almost a year after the birth of my second child, my body felt broken. Every virus my kids had, I caught, too, and sleep deprivation, lack of exercise, and a rotten diet—the trifecta experienced by all new parents—were taking their toll. With my immune system in the same place as my mood (severely depleted) I wandered the aisles of Whole Foods and filled my cart with promising-sounding nutritional supplements: Cat’s Claw Defense Complex, Rescue Remedy, Wellness Formula. As I swiped my credit card to pay the bill, it occurred to me that for that much money I could have gone to a specialist.

Two weeks later, still feeling sluggish, I went to see my internist, who gave me a full physical, some homeopathic cures of her own, and an injection of vitamin B12 in my butt. The effect seemed immediate. Driving home, I felt a faint electric buzz of energy, the sort of oomph an afternoon espresso can provide. But there was none of the edge I get with caffeine; the buzz stayed steady, a hum of vitality that took me through the rest of the day and into the evening until I powered down with ease, slipping into slumber like a lion with a belly full of prey. The next day I continued to feel great. I’d say the effect lasted about 24 hours.

B12 shots are massive doses of the water-soluble vitamin—found in foods such as shellfish, beef liver, and fortified breakfast cereals—that is essential for neurological function, red blood cell formation, and DNA synthesis. Most people get the recommended dietary allowance of B12 (2.4 micrograms for adults, more for pregnant or lactating women and the elderly) through their daily intake of food. The typical injection, a vial of neon red liquid that resembles the dyed sugar water I put in my hummingbird feeder, contains 1,000 micrograms of B12, or in excess of 400 times more than what the average person requires. Proponents of B12 shots claim they turbocharge the metabolism (read: make you thinner), strengthen the immune system, and help cure fatigue, insomnia, even depression.

But do they? Ever since B12 emerged in the ’60s, when it was often mixed with amphetamines, and then later, when everyone from Madonna to Margaret Thatcher was trying it out, its efficacy has been the subject of debate. Mostly the argument pits Western medical practitioners against those who favor homeopathic and alternative treatments. My internist, Sabena Toor, straddles that divide. A third-generation physician who has also studied ayurvedic medicine, she calls B12 injections “an integral part” of her practice. Toor says her patients rave about their benefits, and she herself relies on them when she needs a boost, like when she’s worn out from a long airplane flight or “when I haven’t been good—you can’t do everything perfectly all the time, and B12 helps.” For me she recommended shots every two weeks.


Nevertheless there is no medical evidence that injections of vitamin B12 promote health in anyone other than those who are suffering from a B12 deficiency. “It’s an old wives’ tale,” says David Heber, M.D., director of UCLA’s Center for Human Nutrition. According to Heber, the only reason to take extra B12—and it doesn’t have to be injected; it can be taken as a pill or under the tongue—is when there is a deficiency that can be caused by pernicious anemia, celiac or Crohn’s disease, or weight loss procedures such as gastric bypass surgery, which interferes with the body’s ability to extract vitamins from food. In addition, as we age, our ability to absorb B12 from food declines, which puts the elderly at higher risk of deficiency. According to The New York Times in 2011, as many as 30 percent of older adults may lack sufficient B12. That same year the National Institutes of Health indicated that 1.5 percent to 15 percent of the nation is deficient.

For that group a hit of B12 can seem like a magical cure. “As is true for many of the vitamins discovered in the early 20th century, the effects of B12 seemed miraculous,” Heber explains. “You had people suffering from anemia, and suddenly they were healed.” Heber remembers being at a hospital in Bishop, California, when a wheelchair-bound man who had undergone gastric bypass surgery came in complaining of fatigue. Shortly after receiving a B12 injection, he got up and walked. “Seeing that sort of experience, even for a doctor, stays with you,” says Heber.

If you’re wondering, as I did, how to find out whether you’re B12 deficient, don’t waste your time. The test isn’t covered by most insurance companies. And since having too much B12 isn’t harmful (the body simply excretes the excess), it’s easier and cheaper to just get a shot (B12 injectables cost $14 apiece if bought online or $20 to $70 at a spa or doctor’s office).

So how to explain all the anecdotal evidence that seems to prove B12 works for so many? Some research indicates that elevated doses of B vitamins improve sensory-motor control. A 1989 study published in the International Journal for Vitamin and Nutrition Research revealed that marksmen who received vitamin B shots improved their firing accuracy. Then there’s the placebo effect. Even if the extra vitamins themselves aren’t having a physiological impact, the ritual of getting a shot from a trained professional can help quell anxiety or provide a better sense of control.

“Sometimes just seeing an objective third party and unloading your issues makes you feel better,” says film director Peyton Reed, who once had a doctor give him a B12 shot on set when he was on the cusp of getting a cold—an injection that he believes kept the cold at bay. (Hollywood seems to love B12 shots; Sony Pictures keeps a physician and licensed nurses on its lot full-time who can administer them.) “Call it the Flintstones Vitamin Effect,” Reed says. “I take a multivitamin every day to stay healthy, but do I have empirical evidence it works? No, only that my urine is more yellow. Still, I feel better because I feel like I’ve done something positive for my body. That’s how I felt about the B12 shot.”

Humans aren’t the only ones getting their fix. When filmmaker Laura Nix’s elderly cat had an intestinal blockage, her vet suggested a B12 injection along with an enema. “Suddenly the old lady had pep in her step,” Nix reports. “Usually after a trip to the vet, she’d pass out asleep, but she was playing like a little kitten.” Nix credits the shot, not the enema. But ultimately it probably doesn’t matter: The cat got friskier, Reed didn’t catch a cold, and I had more energy—all after receiving big red shots. Whether we go to a doctor with decades of medical expertise or stroll the aisles of a health food store, in the end we’re paying to feel better—hopefully we are better, too—and to alleviate our illnesses, real or imagined, with a pill, a shot, or a poop. If you think a B12 shot will give you more stamina, help you lose weight, or make nodding off a bit easier at night—well, you might be right.

So why not play a little trickery on the body by curing what maladies you can with a harmless treatment that may, or may not, benefit you tremendously? Who cares if it’s all in your mind? My mother taught me to rub Vicks VapoRub on my feet when I felt I was catching a cold and to put a key down my back to stop nosebleeds; I’ll swear to the effectiveness of both even without a lick of scientific evidence. Which is why I’m adding another old wives’ tale to the list. Bottoms up—it’s time for my next shot.

Related Content

  • Susan

    For all of us who belong to the Pernicious Anaemia Society (whether or not we have been diagnosed as having Pernicious Anaemia or B12 Deficiency) the effects of B12 injections have been miraculous. Personally, I have gone from having intense pain 24/7 for 5 1/2 years, losing my job and becoming bedbound to being essentially pain free and returning to work part-time as a pharmacist with daily B12 injections.

    The shortcomings of the serum B12 test are numerous. For example, one study found 34% of deficiencies were missed when used along with MMA and Hcy. Another problem is due to genetic mutations to genes involved in the methylation cycle, these are only found upon genetic testing and serum B12 may appear normal.

    I recommend reading Could It Be B12?: An Epidemic of Misdiagnosis and watching this documentary called Diagnosing and Treating B12 Deficiency on YouTube:

  • Mrs Healthy

    I started getting B12 at the doctor’s but found that is was way too expensive! So guess what? I found a place that sold them online! That’s right! 30 injections for $34.95! Now that was a huge savings! I believe in paying forward!

  • Sally Pacholok

    Your article unfortunately downplayed the seriousness of B12 deficiency—and made it sound like a placebo. B12 is not an “old wives’ tale.” You did write a short paragraph giving way to some of the reasons a person could be B12 deficient, but did not touch on the essence of the problem in the U.S. and around the world. Patients are frequently misdiagnosed! Symptomatic patients are not being screened or treated. Are you aware that B12 deficiency causes depression, confusion, dementia, mental illness, balance problems, tremor, dizziness, vascular occlusions, and numbness to the extremities? It can progress to permanent nerve and brain damage. There are many malpractice cases where patients have been permanently injured. The American Journal of Clinical Nutrition reports that 16% (48 million) Americans have a B12 deficiency, other experts report it to be as high as 25%. Are you aware that many infants and children are injured from B12 deficiency, because during pregnancy their mom didn’t have enough B12? B12 deficiency causes developmental delay and if not recognized & treated, can lead to intellectual disabilities. The number one reason a person is B12 deficient is from a malabsorption issue, but certain medications, autoimmune disease, nitrous oxide, and the vegetarian/vegan diet also can cause it. Many people (and their doctor) don’t realize they have a problem. I would be pleased to be interviewed for an informative article about B12 deficiency and how Hollywood could help! I have co-authored Could It Be B12? An Epidemic of Misdiagnoses, Quill Driver Books (2nd Ed.-2011) which won the Indie Excellence Award for best health book. Our book has been translated in Dutch, Slovenian, and now being published in India. Our book was made into a documentary in 2012 and a screenplay has been completed to be made into a movie regarding my life-long battle to improve the country’s health care system and expose substandard care. We have started a national campaign regarding B12 deficiency and would love to educate your readers. Unlike Hollywood, who easily gets B12 injections from their doctors at an inflated price—the average American is being undiagnosed and not treated. Please visit
    Sally Pacholok, RN, BSN
    Jeffrey Stuart, DO

    • Jim Herd

      Indeed, Sally, as a result of similar articles, tragically even many doctors believe that b12 injections are a placebo. In the UK, people who have been diagnosed with B12 deficiency, the cause of which is often undiagnosed, receive only one injection every 3 months on the NHS. This treatment protocol was arrived at based on studies of people with pernicious anaemia and the rather dangerous assumption that no one could possibly need more frequent injections with B12 than someone with PA. At that time doctors simply did not understand enough about B12 and the methylation cycle to make that decision and, unfortunately, they still don’t know enough.

      Very many people with B12 deficiency of unknown aetiology actually do need far more frequent, possibly daily, injections or they continue to deteriorate and go on to develop other serious illnesses which typically aren’t linked to their B12 deficiency by doctors but, in fact, are. The consequences of the use of the failed serum B12 test on the health of a huge proportion of the world’s population is incalculable and when they do become clear some serious questions will need to be asked of the medical profession.

      It is becoming clear that many people have mutations of important genes involved in various aspects of the methylation cycle. Some may be live perfectly healthy lives even with these mutations but all it takes is an illness, drug treatment, stress or some other environmental factor to cause an imbalance in their vitamin stores, throwing their methylation cycle into chaos and leading to serious illness. In fact, I believe that even someone without such genetic problems can end up with methylation cycle issues and problem with vitamin B12, folate, B6 and other vitamins and minerals.

      It’s definitely time for this issue to be taken seriously by the media and the medical profession. It is causing a lot of unnecessary suffering and death.

  • Rebecca Loader

    “It’s an old wives’ tale,” says David Heber, M.D., director of UCLA’s Center for Human Nutrition. According to Heber, the only reason to take extra B12—and it doesn’t have to be injected; it can be taken as a pill, is when there is a deficiency that can be caused by pernicious anemia

    The above is WRONG!!!! People with pernicious anemia CANNOT just take a pill because we don’t absorb it in the gut. Yet another doctor who has little clue about PA and how to treat if effectively. But hey, as long as you are getting your massive pay check each week and Hollywood celebrities are being indulged, who cares about getting people well?

  • Andrea MacArthur

    I accept that you mentioned that B12 is fine for those with a B12 deficiency but that’s the whole problem – many people are not being diagnosed due to the flawed tests and ignorance of the medical profession. I spent 15 years deteriorating before I diagnosed myself. Fortunately, my doctors then did everything they could to help me but by then I’d suffered permanent loss of my bowel and bladder function, disablement, severe neuropathic pain and was close to death. I lost count of the number of specialists I saw during that time.

    I notice you mention Margaret Thatcher’s use of B12 injections. Perhaps it is no coincidence that this astute lady succumbed to dementia in her final years, possibly after having ceased being given B12 injections? Who knows?

    I despair that those with a true functional B12 deficiency are the losers due to the fashion trend of celebrities using B12 to bolster their chaotic social lives. As a result, B12 is seen as a trendy health fad instead of the vital life-sustaining substance it is to the thousands who, through no fault of their, own cannot absorb it in the normal way.

  • Deb

    I have a B12 deficiency and it is really disturbing and hurtful to read these people that are using these shots just because they “need a little boost just because they are worn out”. This past summer there was a shortage of B12 and for those of us that count on having the B12 just to make it out of bed, had to go without. Never have I felt “a little boost” from the injections, but it sure is nice to think that it helps me somewhat function for a few days. For those that are worn out, please stick to the oral or sub-lingual B12 and leave the injections to those who truly require it.

  • jules

    There is an amazing amount of scientific evidence that being deficient on B12 is an very serious illness. In 1934 3 dr’s were awarded the Nobel Prize for uncovering the cause of the “pernicious” anaemia.
    Perhaps it is not spectacular when one is not deficient in B12, but it is life saving for people who are deficient!
    It’s not a placebo effect, that is for sure.

  • Robert Pierce

    Nice blog, thanks for sharing the information. I was advised to take Vitamin b 12 sublingual by my doctor when i tested for low RBC. Have been taking them for six months and i m a lot better now.

  • Tony

    eBay seller with pharma grade B12 Hydrocobalamin ampoules. Check it out. Great Prices.

  • Pingback: Seeing Red: Do B12 Injections Work?()

  • robert cayne

    Can it be that B12 injections are safe and effective for schizophrenia?