B12 shots are sold at med spas and wellness bars as a quick energy fix, and injections were long the standard treatment for deficiency. But the research on oral B12 has shifted the picture. For many people, high-dose oral B12 raises levels just as well. For some, injections are still essential.
Written by Vita Globe Editorial Team | Reviewed against a Cochrane systematic review, NICE guidance and peer-reviewed research
Do you need B12 injections, or do oral supplements work?
A Cochrane review found that high-dose oral B12 and injections raised B12 levels by similar amounts in people with deficiency, although the evidence was low quality[1]. A later randomized trial in older adults came to a similar conclusion[2]. Injections remain important for people with severe deficiency or neurological symptoms, and often for pernicious anemia, as decided by a clinician[3].
Caveat: Oral vs. injection is a medical decision if you're being treated for deficiency. Don't switch without talking to your provider.
Sources: Cochrane review, 2018 · OB12 trial, 2020 · NICE NG239 · Verified 2026-09-27
IN THIS ARTICLE
How do B12 shots and oral B12 differ?
B12 injections (usually hydroxocobalamin or cyanocobalamin) go into a muscle and bypass the gut entirely. Oral B12, whether it's a tablet or a gummy, has to be absorbed through the digestive tract.
That matters because normal B12 absorption depends on intrinsic factor, a protein made in the stomach. But there is a second, backup route: a small percentage of any dose is absorbed by passive diffusion, even without intrinsic factor[4]. At a 1,000 mcg dose, the NIH estimates about 1.3% is absorbed, which is still well above the daily requirement[5]. That backup route is why high-dose oral B12 can work for many people.
What does the research say about oral vs. injected B12?
A 2018 Cochrane systematic review compared oral and intramuscular B12 in people with deficiency. It found that high-dose oral B12 and injections raised blood B12 levels by a similar amount. The reviewers rated the evidence as low quality, since the trials were few and small[1].
A pragmatic randomized trial in primary care (the OB12 trial) in older adults reached a similar conclusion, finding oral B12 non-inferior to injections for normalizing B12 levels[2].
What these trials measure is blood levels. They are less clear about neurological outcomes in severe deficiency, which is one reason guidelines still keep injections for certain groups.
Who still needs B12 injections?
The UK's NICE guideline on B12 deficiency points toward injections for people with, for example, suspected pernicious anemia (autoimmune gastritis), neurological symptoms, severe deficiency, or conditions that seriously affect absorption, and asks clinicians to decide the treatment route with the patient[3]. Other reviews also point to neurological involvement as a reason to start with injections[6].
If you have been diagnosed with pernicious anemia or are already on injections, don't stop or switch without your clinician's input.
Do B12 shots give you energy if you're not deficient?
Wellness clinics often market B12 shots for energy, weight loss or a quick pick-me-up. There is little evidence to support that for people with normal B12 levels. A meta-analysis of randomized trials found no clear benefit of B12 supplementation on depressive symptoms or cognition in people without advanced neurological problems, and too little data to judge fatigue[7]. We cover the energy question fully in Does B12 Actually Give You Energy?
The honest summary
- For many people with low B12, high-dose oral B12 raises levels about as well as injections.
- Injections are still important for severe deficiency, neurological symptoms and some absorption disorders.
- If you are not deficient, shots are unlikely to give you a noticeable boost.
- The right route is a conversation to have with your clinician, based on your test results.
Our option
Vita Globe Vitamin B12 Gummies for Adults
If your clinician agrees that an oral option makes sense for you, our B12 Gummies for Adults provide 1,000mcg of vitamin B12 (as cyanocobalamin) per two-gummy serving, taken once a day. It's a chewable option for people who prefer gummies to pills or needles, and it supports cellular energy production and red blood cell formation.*
Frequently asked questions
Are B12 shots better than oral supplements?
For raising blood levels in many people with deficiency, high-dose oral B12 performs similarly, based on low-quality evidence[1]. Injections are still preferred in certain situations, such as neurological symptoms[3].
How often do you need B12 injections?
Schedules vary. Treatment often starts with more frequent loading doses, followed by maintenance injections every few months, as set by your clinician[3].
Can I switch from B12 injections to oral B12?
Some people can, but only with their clinician's guidance and follow-up blood tests. People with pernicious anemia or neurological symptoms may need to stay on injections.
Do gummies absorb as well as tablets?
There isn't head-to-head research on B12 gummies versus tablets. What matters most is the dose and your ability to absorb it. For the forms of B12, see Methylcobalamin vs. Cyanocobalamin.
Sources
- Wang H, et al. Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency. Cochrane Database Syst Rev. 2018;3:CD004655. doi:10.1002/14651858.CD004655.pub3
- Sanz-Cuesta T, et al. Oral versus intramuscular administration of vitamin B12 for vitamin B12 deficiency in primary care: a pragmatic, randomised, non-inferiority clinical trial (OB12). BMJ Open. 2020;10(8):e033687. doi:10.1136/bmjopen-2019-033687
- National Institute for Health and Care Excellence. Vitamin B12 deficiency in over 16s: diagnosis and management (NICE guideline NG239). 2024. nice.org.uk/guidance/ng239
- Carmel R. How I treat cobalamin (vitamin B12) deficiency. Blood. 2008;112(6):2214-2221. doi:10.1182/blood-2008-03-040253
- Office of Dietary Supplements, National Institutes of Health. Vitamin B12: Fact Sheet for Health Professionals. Updated July 2, 2025. ods.od.nih.gov
- Langan RC, Goodbred AJ. Vitamin B12 deficiency: recognition and management. Am Fam Physician. 2017;96(6):384-389. aafp.org
- Markun S, Gravestock I, Jäger L, Rosemann T, Pichierri G, Burgstaller JM. Effects of vitamin B12 supplementation on cognitive function, depressive symptoms, and fatigue: a systematic review, meta-analysis, and meta-regression. Nutrients. 2021;13(3):923. doi:10.3390/nu13030923
About the Vita Globe Editorial Team
The Vita Globe Editorial Team researches and writes our wellness content, working from peer-reviewed research, systematic reviews and guidance from bodies such as the NIH and the FDA. We cite our sources inline and update articles when the evidence changes.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and is not a substitute for medical advice. Talk to your healthcare provider before starting any new supplement, particularly if you are pregnant, nursing, taking medication, or caring for a child.
