Methylcobalamin
Research reviewed: Up until 03/2026
Methylcobalamin (Methyl-B12 / Mecobalamin) is a dietary supplement with 8 published peer-reviewed studies involving 1,540 participants, researched for Neurological Health, Peripheral Neuropathy, Sleep Quality and 2 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Neurological Health
StrongPeripheral Neuropathy
StrongSleep Quality
ModerateSleep Quality
ModerateHomocysteine Reduction
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Neurological Health
To assess methylcobalamin supplementation on nerve conduction velocity in patients with diabetic neuropathy.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess methylcobalamin supplementation on nerve conduction velocity in patients with diabetic neuropathy.
Dose
500 µg/day methylcobalamin
Participants
100 patients with diabetic peripheral neuropathy
Duration
16 weeks
Results
Methylcobalamin significantly improved NCV in sural and peroneal nerves and reduced vibration perception threshold. Subjective neuropathic pain scores also improved significantly.
How They Measured It
Nerve conduction velocity (NCV), vibration perception threshold, pain scores
To evaluate methylcobalamin for diabetic peripheral neuropathy.
Study Type
Systematic review and meta-analysis
Purpose
To evaluate methylcobalamin for diabetic peripheral neuropathy.
Dose
Various (oral and injectable methylcobalamin)
Participants
Pooled data from 12 RCTs
Duration
8-24 weeks
Results
Methylcobalamin significantly improved nerve conduction velocity and reduced neuropathic symptoms across trials. Meta-analysis confirmed meaningful benefit for both motor and sensory nerve function in diabetic neuropathy.
How They Measured It
Pooled NCV, pain, and neurological symptom scores across RCTs
Peripheral Neuropathy
To evaluate methylcobalamin in chemotherapy-induced peripheral neuropathy.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate methylcobalamin in chemotherapy-induced peripheral neuropathy.
Dose
1,500 µg/day oral methylcobalamin
Participants
121 cancer patients receiving cisplatin-based chemotherapy
Duration
12 weeks
Results
Methylcobalamin significantly reduced severity of chemotherapy-induced neuropathy as measured by TNS and pain VAS. Nerve conduction scores were better preserved in the methylcobalamin group.
How They Measured It
Total Neuropathy Score (TNS), NCS, pain VAS
To compare methylcobalamin vs cyanocobalamin for neuropathy in B12-deficient patients.
Study Type
Randomised, controlled trial
Purpose
To compare methylcobalamin vs cyanocobalamin for neuropathy in B12-deficient patients.
Dose
1,000 µg/day methylcobalamin vs cyanocobalamin
Participants
180 patients with B12 deficiency neuropathy
Duration
6 months
Results
Methylcobalamin produced significantly greater improvements in neurological symptoms and serum MMA normalisation compared to cyanocobalamin. Methylcobalamin is neurologically superior due to direct availability for myelin synthesis.
How They Measured It
Serum B12, MMA, homocysteine, neurological symptom scores
Sleep Quality
To assess methylcobalamin on circadian rhythm and sleep quality.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess methylcobalamin on circadian rhythm and sleep quality.
Dose
3 mg/day methylcobalamin
Participants
50 adults with circadian sleep disorders
Duration
4 weeks
Results
Methylcobalamin supplementation significantly improved sleep quality and advanced circadian rhythms. Melatonin secretion timing improved and subjective sleep scores increased significantly compared to placebo.
How They Measured It
Polysomnography, sleep diary, melatonin profiles
Sleep Quality
To assess methylcobalamin on circadian rhythm and sleep quality.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess methylcobalamin on circadian rhythm and sleep quality.
Dose
3 mg/day methylcobalamin
Participants
50 adults with circadian sleep disorders
Duration
4 weeks
Results
Methylcobalamin supplementation significantly improved sleep quality and advanced circadian rhythms. Melatonin secretion timing improved and subjective sleep scores increased significantly compared to placebo.
How They Measured It
Polysomnography, sleep diary, melatonin profiles
Homocysteine Reduction
To evaluate methylcobalamin combined with methylfolate for homocysteine lowering.
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate methylcobalamin combined with methylfolate for homocysteine lowering.
Dose
1,000 µg/day methylcobalamin + 400 µg methylfolate
Participants
180 adults with elevated homocysteine
Duration
12 weeks
Results
The combination significantly reduced homocysteine by 31% and normalised MMA levels in adults with hyperhomocysteinaemia. Methylcobalamin was superior to cyanocobalamin for homocysteine reduction in this trial.
How They Measured It
Serum homocysteine, serum MMA, B12 status markers
To evaluate vitamin B12 forms on homocysteine reduction and cardiovascular risk.
Study Type
Systematic review and meta-analysis
Purpose
To evaluate vitamin B12 forms on homocysteine reduction and cardiovascular risk.
Dose
Various B12 forms
Participants
Pooled from multiple RCTs
Duration
Various
Results
Meta-analysis confirmed significant homocysteine reduction with B12 supplementation. Methylcobalamin appeared to have superior bioavailability for neurological tissue and homocysteine reduction compared to cyanocobalamin.
How They Measured It
Pooled homocysteine changes across RCTs by B12 form
Frequently Asked Questions
Common questions about Methylcobalamin research
There are currently 8 peer-reviewed studies on Methylcobalamin (Methyl-B12 / Mecobalamin), involving 1,540 total participants. Research covers Neurological health, Peripheral neuropathy, Sleep quality and 1 more areas. The overall evidence strength is rated as Very Strong.
The evidence is currently rated as "Very Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (8 human studies), and reported outcomes.
Methylcobalamin has been researched for: Neurological health, Peripheral neuropathy, Sleep quality, Homocysteine reduction. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 8 out of 8 studies are human trials. Human trials carry more weight in our evidence scoring system.
Similar Supplements
Other supplements researched for similar health goals
