Vitamin B12: which form, what each one does, and the dose that worked
Vitamin B12 comes in many forms, and what it does depends on the form. Every result below names the form it came from. Pick the form you take to see its own studies, products and what the biohackers say about it. This page is educational, not medical advice.
What it does, by goalMembersThe top 5 of 17 goals
5 of these 49 human studies gave vitamin B12 by injection, not by mouth.
| Goal | What the studies show | Studies | Dose that worked |
|---|---|---|---|
| Improved in studies Methylcobalamin: 2 of 7 improved, 2 no effect · Cyanocobalamin: 1 of 2 improved, 1 no effect | 9 | cyanocobalamin 500 mcg | |
| Improved in studies Cyanocobalamin: 1 of 4 improved, 1 no effect · Methylcobalamin: 1 of 4 improved, 1 no effect · Hydroxocobalamin: 1 study, no clear result · 1 by drip, injection or inhaler | 9 | cyanocobalamin 1 mg · methylcobalamin 1 mg | |
| Improved in studies Methylcobalamin: 2 of 3 improved · Cyanocobalamin: 1 study, no clear result | 4 | – | |
| Improved in studies Methylcobalamin: 2 of 2 improved · Cyanocobalamin: 1 study, no clear result | 3 | methylcobalamin 500 mcg | |
| Improved in studies Methylcobalamin: 1 of 2 improved · Cyanocobalamin: 1 of 1 improved · 1 by drip, injection or inhaler | 3 | methylcobalamin 1.5 mg | |
| Improved in studies Methylcobalamin: 1 of 5 improved, 2 no effect · Cyanocobalamin: 1 study, no effect · 2 by drip, injection or inhaler | 6 | – | |
| Improved in studies Cyanocobalamin: 1 of 2 improved · Methylcobalamin: 2 studies, no clear result | 4 | cyanocobalamin 1 mg | |
| Improved in studies Cyanocobalamin: 1 of 1 improved · Methylcobalamin: 3 studies, no clear result | 4 | cyanocobalamin 500 mcg | |
| Improved in studies Hydroxocobalamin: 1 of 1 improved · Cyanocobalamin: 1 study, no clear result | 2 | hydroxocobalamin 500 mcg | |
| Too few studies Cyanocobalamin: 2 studies, no clear result · Methylcobalamin: 1 study, no clear result | 3 | – | |
| Too few studies Cyanocobalamin: 1 study, no effect · Methylcobalamin: 1 study, no clear result | 2 | – | |
| Too few studies Adenosylcobalamin: 1 study, no clear result · Cyanocobalamin: 1 study, no clear result | 2 | – | |
| Too few studies Cyanocobalamin: 1 study, no clear result · Methylcobalamin: 1 study, no clear result | 2 | – | |
| Too few studies Cyanocobalamin: 1 study, no clear result · 1 by drip, injection or inhaler | 1 | – | |
| Too few studies Methylcobalamin: 1 study, no clear result | 1 | – | |
| Too few studies Cyanocobalamin: 1 study, no clear result | 1 | – | |
| Too few studies Cyanocobalamin: 1 study, no clear result · 1 by drip, injection or inhaler | 1 | – |
Members see which goal each result is for, and the products for it. Start My 7-Day Free Trial →
Products – highest ranked firstMembersThe top 3 of 22
Dose and safetyThe dose that worked and the upper limit
The doses that worked, by form, in the studies taken by mouth: methylcobalamin 500 mcg to 1.5 mg, cyanocobalamin 500 mcg to 1 mg, hydroxocobalamin 500 mcg a day.
Biohacker panelMembersWhich forms of vitamin B12 our 10 biohackers name
Questions people askMembersAnswered from the figures on this page
Which form of vitamin B12 is best?
Answer for members.
How much vitamin B12 a day?
Answer for members.
Can I take vitamin B12 with my meds?
Answer for members.
Members see the answers, checked against their own meds and goals. Start My 7-Day Free Trial →
Educational, not medical advice. Figures come from the human studies on PubMed we have graded; a study counts for a form when it names the form it used. Updated as new studies arrive. How we grade →