Thorne Research Vitamin B12 as Methylcobalamin Review
Thorne Vitamin B12 as Methylcobalamin is presented as an active, tissue-ready form of vitamin B12 intended to improve bioavailability. The page states that Vitamin B12 is essential for numerous processes in the body and that while B12 is often found in different forms in nutritional supplements, clinical evidence indicates that the body uses the methylcobalamin form more efficiently than other forms such as cyanocobalamin. Each capsule provides 1 mg of Vitamin B12 as Methylcobalamin. The serving size is 1 capsule and the container holds 60 servings. The Summary section advises taking 1 capsule one to three times daily. The product is described as particularly well suited for individuals with increased B12 needs, such as vegans, vegetarians, older adults, or those with low stomach acid. It is stated to be third-party tested for purity and quality and free from gluten, dairy, and soy. The benefits listed on the page include support for healthy nerve function and feeling, promotion of the body's methylation pathways, balancing of circadian rhythms to enhance restful sleep, support for healthy homocysteine levels, promotion of cardiovascular health, and benefits to cognitive function. The page lists groups who may benefit: vegans or vegetarians whose diets are low in B12, people with low stomach acid, the elderly who may eat fewer B12-rich foods, anyone with anemia because B12 is necessary for red blood cell formation, and individuals on certain medications including a med, meds, and seizure medications. Thorne states the formula was developed with scientific rigor, with each ingredient carefully selected, clinically studied, and tested through multiple rounds of quality control to ensure purity, potency, and consistency. The page states the product has been third-party tested and certified to verify that what is in the package matches the label and to confirm it contains no unsafe levels of contaminants such as heavy metals, pesticides, and microorganisms. Warnings on the page state the product is contraindicated in individuals with a history of hypersensitivity to any of its ingredients, that pregnant users should consult a health-care practitioner before use, and that there are no known adverse interactions or contraindications at publication date. The FAQ notes that individual results vary depending on starting B12 level, absorption, diet, medications, and consistent use, and that suspected deficiency should be addressed with a health-care practitioner and testing.
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Study, Trial or Testing Result Summary
Members Only19 human studies · 5 improved
4 of these 19 human studies gave vitamin b12 by injection, not by mouth.
Each capsule gives 1000 micrograms of vitamin B12 as methylcobalamin. That is below the 3000 micrograms a day noted for the studies, though that figure is unclear. A review of 16 randomized trials in 6276 people without B12 deficiency found no benefit for thinking or depression. Only one of those trials measured fatigue, so the effect on energy could not be judged [1]. Most other controlled trials tested blends or very small amounts of B12. About three years of low-dose B vitamins, with 0.02 milligrams of B12, did not improve quality of life in 2029 heart disease survivors [2]. A multinutrient supplement did not change fatigue in 172 dialysis patients [3]. A combination supplement with 2.5 micrograms of B12 did not reduce fatigue in 41 trained cyclists [4]. A single 1000 microgram B12 injection did not ease voice fatigue in 20 singers [5]. Injections of liver extract with folic acid and B12 did no better than placebo in 15 people with chronic fatigue syndrome [6]. No study given tested this capsule form alone for energy in people who are not deficient. Animal and cell studies are never counted.
See all 19 studies →Hide the studies
- Across 16 randomized trials with 6276 people without vitamin B12 deficiency, B12 did not improve thinking or depression, and only one trial looked at fatigue so it could not be analyzed.Effects of Vitamin B12 Supplementation on Cognitive Function, Depressive Symptoms, and Fatigue: A Systematic Review, Met…
- In 2029 heart disease survivors, about 3 years of low-dose B vitamins including 0.02 mg B12 did not improve quality of life, and slightly more activity limits from emotional problems were seen.B vitamin and/or n-3 fatty acid supplementation and health-related quality of life: ancillary findings from the SU.FOL.O…
- In 172 dialysis patients who finished, 12 weeks of a multinutrient supplement containing B12 did not change fatigue or quality of life versus placebo, though heart rate variability and a herpes virus measure improved.Effects of nutritional supplementation on fatigue, and autonomic and immune dysfunction in patients with end-stage renal…
- In 41 trained cyclists, 4 weeks of a combination supplement including 2.5 mcg B12 did not improve aerobic or anaerobic performance or fatigue measures compared with placebo, though blood lactate was lower after hard exercise.l-Carnitine and Alpha-Lipoic Acid Fail to Improve Anaerobic and Aerobic Performance in Trained Cyclists Despite a Reduct…
- In 25 healthy recreationally active adults, a single dose of a pre-workout supplement containing vitamin B12 as methylcobalamin, along with caffeine, raised self-reported vigor and energy compared with a placebo drink, though exercise performance did not change.Effects of acute ingestion of a pre-workout dietary supplement with and without p-synephrine on resting energy expenditu…
- In 25 resistance-trained people, a week of a pre-workout drink containing 45 mcg B12 and other ingredients helped maintain some strength and lifting measures versus placebo but did not change cycling time trial performance.Short-Term Effects of a Ready-to-Drink Pre-Workout Beverage on Exercise Performance and Recovery.
- In 20 singers with mild vocal symptoms, a single 1000 mcg B12 injection did not improve voice fatigue or singing measures more than a placebo injection.Effect of Vitamin B12 Injection on the Vocal Performance of Professional Singers: A Randomized, Double-blind, Placebo-Co…
- In 15 people with chronic fatigue syndrome, injections of liver extract with folic acid and B12 worked no better than placebo, which had a strong response.Liver extract-folic acid-cyanocobalamin vs placebo for chronic fatigue syndrome.
- In a chart review of 2142 people with fibromyalgia, 42.4% had vitamin B12 deficiency, and deficiency was linked to higher odds of fatigue (odds ratio 1.39) after adjusting for vitamin D.Association of Vitamin B12, Vitamin D, and Thyroid-Stimulating Hormone With Fatigue and Neurologic Symptoms in Patients …
- In a retrospective study of 689 children without complaints, 23.2% had vitamin B12 deficiency and it was linked to vitamin D deficiency, but no supplement was tested for energy.Is There An Association Between Vitamin B12 Level and Vitamin D Status in Children?
- In 335 older adults, vitamin B12 levels were not associated with frailty, and no supplement was tested.Association between serum vitamin B12 level and frailty in older adults.
- Women with fibromyalgia had lower vitamin B12 levels than 58 healthy women, and lower levels were linked to more tender points, though this study did not test supplements.Could ferritin, vitamin B12, and vitamin D play a role in the etiopathogenesis of fibromyalgia syndrome?
- Vitamin B12 levels were normal in 55 people with primary fibromyalgia, who reported muscle fatigue as one of their most disabling symptoms.Primary fibromyalgia. A clinical and laboratory study of 55 patients.
- In a survey of 38 people with chronic fatigue syndrome or fibromyalgia who had weekly or more frequent B12 injections for six months or more, 15 were good responders who rated themselves much or very much improved, and higher doses and longer use were linked to better response.Response to vitamin B12 and folic acid in myalgic encephalomyelitis and fibromyalgia.
- In a retrospective review of 38 children with neurological symptoms of vitamin B12 deficiency, all recovered within one month of B12 supplementation; fatigue was among the symptoms but was not reported separately.Neurological symptoms of vitamin B12 deficiency: analysis of pediatric patients.
- In a study of 37 adults with pulmonary arterial hypertension, 29% had a functional vitamin B12 deficiency, but no supplement was tested, so the study does not show whether B12 improves energy.Nutritional status in pulmonary arterial hypertension.
- In a small case series of 20 infants with vitamin B12 deficiency, who were treated with cyanocobalamin, clinical and lab findings improved overall, though energy was not separately reported and the dose and duration were not stated.Vitamin B12 Deficiency in Infants.
- All 5 people with ALS who received methylcobalamin injections reported more energy and less fatigue, based on interviews; the dose was not stated.Patients' experiences with methylcobalamin injections in amyotrophic lateral sclerosis.
- This survey of hypothetical scenarios found people kept taking B12 for fatigue after a small symptom improvement, showing post hoc bias rather than any real effect of B12 on energy.Post Hoc Bias in Treatment Decisions.
Review Totals and Summary
Members Only3,325 reviews · 90% positive
Thorne Research Vitamin B12 as Methylcobalamin is well received overall, with about 373 ratings across the stores and most of them very positive. Energy is the most common benefit people mention, and a few complaints concern delivery or a lack of effect. These notes cover the capsules only. No other forms were included. **What buyers say it did for them:** Energy comes up most often, usually as a steady lift rather than a jolt. One buyer wrote, "more sustained energy throughout the day," and another "Noticed improvement in energy within a few days." Others say they have "more energy and don't feel so tired," and one reports a better sense of energy and sleep within three weeks. Several mention blood work: one says it "brought my B12 levels up in the normal range," and they report that deficiency symptoms have subsided. Another says their blood work is improving. One person rates it "better than the B-12 shots from a doctor." **What they complain about:** Complaints are few. The clearest is a subscription problem. One 1-star reviewer said the second bottle "never showed up" even though they were charged almost three weeks earlier. A 2-star reviewer felt no improvement in energy after a month. The Thorne.com summary notes that the written comments don't explain the small number of low ratings. That page's star breakdown shows 12 one-star and 2 two-star ratings among 205. **Taste, smell, pill size, form:** Buyers call the capsule easy to swallow. One says "No after taste." The reviews say nothing about smell. **Value for money:** Value gets little comment. One buyer said it "cost a little more" than ordinary B12 but chose it because it absorbs faster. An eBay reviewer said it offers good value, though that page holds a single rating from a third-party seller. **Who it seems to suit and who it did not:** It seems to suit people who want to correct or monitor a B12 shortfall, including those whose doctor or neurologist suggested B12. It also suits buyers who trust Thorne's ingredient quality; one has taken it daily for over a year. Some people compared it favorably with "Big Pharma" products. Two people bought bottles for themselves and a spouse. It did not suit the buyer who noticed no energy change after a month. The Thorne.com overview says opinions on how noticeable the difference is vary. The pages give little detail on long-term effects or on specific groups, such as people with low stomach acid. **Delivery and service:** Experiences were mixed. Some praised easy ordering, "Quick delivery and consistent follow up," and "flawless" delivery. The one serious complaint was the missing subscription bottle described above.
Biohacker Summary
Members Only10 of 10 recommend it
Most of the panel recommends vitamin B12, with five of ten giving a latest position of recommends and two more saying they use it, while one warns and two are neutral. People mainly take it for nerve health and myelin, brain function and mood, energy, and to fix a deficiency, and several point to vegans and older people as most likely to run low. Methylcobalamin is the form favored by several, with one preferring a liposomal or micellar version and another suggesting a sublingual form or injections for older people; the only doses given were about 500 as a target blood level and 1 gram taken in the morning by one person. Pairings mentioned include B6 and folate, methylated folic acid for people with an MTHFR mutation, and a B complex. Cautions came from one who advises against it when the diet already covers needs, one who stopped after taking it with fat burner injections and then felt intense emotional and hormonal imbalance, and one who says to avoid it close to bedtime because it boosts light's effect on melatonin.
See all 10 biohackers →Hide the biohackers
Thomas DeLauer · Vitamin B12 · recommends
- Recommends Vitamin B12 for mental health and mood, explaining its role in myelination and neurotransmitter production. They specifically recommend a liposomal and micellar form of methylcobalamin B12 for better absorption and to avoid toxicity.
- Mentions that a single serving of sardines provides vitamin B12 at something like three to four times the daily needs.
- Recommends taking methylcobalamin as a methylated form of B vitamin for mitochondrial function.
- Advises against taking vitamin B12 if one's diet already provides enough, suggesting a B complex or liver capsule instead for B vitamins.
- Was taking Vitamin B12 with fat burner injections, which he later stopped cold turkey, leading to a period of intense emotional and hormonal imbalance.
- Warns that high levels of supplemental vitamin B12 are a risk factor for insomnia, as it is an energy-building supplement, and advises taking it in the morning or lowering the dose.
- Notes that depending on one's diet, adding a good multivitamin might be beneficial, specifically recommending a methylated multivitamin for better absorption and utilization.
- Uses Create's Daily Performance Gummy, which contains a multivitamin, a low dose of creatine, adaptogenic mushrooms, and greens, and also adds a separate creatine gummy later in the day.
- Highlights Vitamin B12 as a significant deficiency in studies, important for brain function, oxygen, neurotransmission, and clearing out homocysteine.
- Notes that vegan populations need to supplement to get vitamin B12 because it can only really be obtained from animal products.
Dr. Eric Berg · Vitamin B12 · recommends
- Recommends taking the natural form of vitamin B12, methylcobalamin, to support nerve regeneration, myelin production, and nerve growth factors.
- Notes that Vitamin B12 is intimately involved in the nervous system and may be behind sciatica and carpal tunnel syndrome.
- Recommends taking vitamin B12 if on a med.
- Briefly mentions Vitamin B12 in relation to neuropathy.
- States that vertical ridges on nails could mean a vitamin B12 deficiency, and slightly brown or grey nails, especially for vegans, could indicate low B12. Completely white nails with a pink strip across the top could also be low B12.
- Recommends incorporating vitamin B12 foods into the diet, especially for those who don't regularly consume animal products, to prevent irreversible damage to the nervous system.
- Dr. Berg mentions that fermented dairy contains vital nutrients, including vitamin B12.
- A vitamin B12 deficiency can cause irreversible damage to your nervous system, so it's important to prioritize acidifying your stomach as you age.
- States that Vitamin B12 is crucial for health and many people are deficient without realizing it.
- Mentions that fortified nutritional yeast varieties may provide vitamin B12.
Dr. Mark Hyman · Vitamin B12 · recommends
- States that vitamin B12 is a nutritional deficiency that impacts mental health.
- Recommends vitamin B12 with vitamin B6 and folate as supplements with strong evidence for PMS.
- Mentions that repletion of vitamin B12 can help safely withdraw someone from meds and that simple vitamin B12 deficiencies are important to address in a depression workup.
- Lists Vitamin B12 as important for nerve health and energy.
- Mentions vitamin B12 as a core nutrient required for methylation, noting that deficiencies can lead to various health issues.
- Recommends supplementing with Vitamin B12 for hair follicle health and growth, especially for vegans, as many people are deficient.
- Recommends checking vitamin B12 levels as a first step before taking any supplements.
- Warns that meds (meds) block the absorption of vitamin B12, which requires stomach acid to be absorbed. Long-term B12 deficiency can lead to depression, neurological problems, and dementia.
- Recommends Vitamin B12 in the form of methylcobalamin, about 1000 micrograms a day, as a methylating vitamin necessary for detoxifying and excreting hormones.
- Dr. Hyman states that vitamin B12 deficiency is common, affecting 80-90% of vegans and vegetarians, and over 20% of adults in the general population, often due to acid blockers, digestive issues, or insufficient intake.
Ben Greenfield · Vitamin B12 · recommends
- Recommends getting vitamin B12 tested and supplementing if deficient, as B12 deficiency can cause damage to the myelin coating around nerves, including cochlear nerves, and improve tinnitus severity scores.
- He recommends Vitamin B12, especially for kids on a vegan or vegetarian diet, as it is essential for nervous system development.
- Mentions that blood testing for an energy crisis would include nutritional things like a vitamin B12 level.
- Ben Greenfield consumes vitamin B12 as part of the Update Energy Drink.
- Lists vitamin B12 as a vitamin that, when combined with others, has a neuroprotective effect on the brain.
- Ben notes that vitamin B12 is in the drink, and Shawn specifies it's the methylated coenzymated form, methylcobalamin.
- Mentions that Haya multivitamin contains Vitamin B12.
- Mentions Vitamin B12 as a nutrient found in animal foods that does not occur in plants.
- Ben states that Vitamin B12 is difficult to obtain on a plant-based diet.
- For vegans, Ben Greenfield recommends supplementing with Vitamin B12 to keep nutrient levels topped off, especially before and during a fast.
Dave Asprey · Vitamin B12 · recommends
- States that Vitamin B12 is extremely important for every kind of brain function and recommends ensuring B12 levels are optimal, around 500, not just barely above normal.
- Recommends taking vitamin B12 if one has a deficiency.
- Dave Asprey notes that it's almost impossible to get vitamin B12 in a vegan diet, and it's primarily found in animal meat.
- Clarifies that Vitamin B12 is completely different from Vitamin B3 and is involved in different pathways, so there is no overlap with NAD pathways.
- If one has a MTHFR mutation and cannot process folic acid, Dave Asprey recommends taking vitamin B12 along with methylated folic acid to lower homocysteine levels.
Siim Land · Vitamin B12 · uses
- Created Microvitamin, a supplement that bundled all the supplements he was taking, to help fund his a med trial.
- States that vitamin B12 deficiency is the most common reason for premature graying of hair and recommends fixing B12 status if it is deficient, as it gives a greater likelihood of reversing gray hair.
- Takes 1 gram of Vitamin B12 from DoNotAge in the morning for longevity.
- Mentions Vitamin B12 as a key nutrient involved in the methylation cycle that helps prevent methionine from raising homocysteine levels.
- Explains that one can store up to 30 years' worth of vitamin B12 if they get a lot of it, particularly from superfoods like clams, liver, and oysters, but most people are not in that position.
Andrew Huberman · Vitamin B12 · neutral
- States that a deficiency in vitamin B12 can be terrible and lead to chronic fatigue-like syndromes, as many parts of mitochondria require B vitamins.
- Recommends taking methyl B12 as part of methylated B vitamins to lower homocysteine levels and reduce cardiovascular risk.
- Has been taking AG1 for over 10 years, once and often twice every day, to ensure he gets all necessary vitamins, minerals, probiotics, and adaptogens, considering it a nutritional insurance policy.
- Has been taking AG1 since 2012 to ensure he gets enough vitamins, minerals, Prebiotic fiber, and other nutrients typically found in fruits and vegetables, providing nutritional insurance.
- Andrew Huberman started drinking AG1 in 2012 and still drinks it once or twice a day because it provides all his foundational nutritional needs, ensuring proper amounts of vitamins, minerals, probiotics, and fiber for optimal mental health, physical health, and performance.
- Recommends the consumption of B12 and other B vitamins, especially folate, as it has been shown to partially decrease cancer risk in people who ingest alcohol, though it does not completely offset it.
- Started taking AG1 in 2012 and still takes it once or twice a day because it covers foundational vitamin, mineral, and probiotic needs, and supports immune system function and a healthy gut microbiome.
- He has been using Athletic Greens for over a decade to cover his vitamin and mineral bases and support his gut microbiome, immune system, gut-brain axis, and mental functions.
- Recommends Methyl B12 as part of methylated B vitamins to lower homocysteine and reduce cardiovascular risk.
Dr. Rhonda Patrick · Vitamin B12 · warns
- Warns that Vitamin B12 enhances light's melatonin-suppressing effects and should be avoided too close to bedtime.
- Notes that a med can cause vitamin B12 deficiency, especially as absorption decreases with age, and suggests a sublingual form or B12 injections for older individuals.
- Discusses the origin of Vitamin B12, suggesting it's a microorganism that propagates in the soil and that animals get it from eating dirt, which is why it's less available in modern, sanitized plant foods.
- Describes a study where female mice fed a diet high in B vitamins, folic acid, and vitamin B12 three weeks before pregnancy had offspring that no longer had yellow fur and were not predisposed to obesity and cancer.
- Dr. Rhonda Patrick explores vitamin B12 and autism risk.
- She takes methyl B12 as part of her Thorne multivitamin, which helps keep her homocysteine levels below 9 micromoles per liter.
- Describes a study where female mice fed a diet high in B vitamins, folic acid, and vitamin B12 had offspring that silenced a gene predisposing them to obesity and cancer.
- Supplements with vitamin B12, but also notes many of the foods he eats are fortified with it, and his levels are fine.
Bryan Johnson · Vitamin B12 · uses
- States that Blueprint essential capsules and soft gels are packed with key vitamins and minerals needed for strong bone health.
Peter Attia · Vitamin B12 · neutral
- Notes that deficiencies in certain vitamins and minerals, such as B12, can be a cause of hair loss in women.
- Explains that when a person is not responding to traditional B vitamins, they will step it up and give them methylcobalamin B12.
- Notes that Ryan Lochte was suspended for a doping rule violation after a social media post showed him taking vitamin B12 in an illegal way, by IV infusion.
RAL Summary
Members OnlyTier 4 for Energy
The failed trials that the ineffective grade relies on mostly tested blends with tiny amounts of vitamin B12, injections or other goals, while the review of 16 trials could not judge fatigue at all, so the evidence is thin and conflicts with strongly positive reviews rather than showing B12 does not work. So it is graded Tier 4, as the studies disagree.
- Emerging: not enough evidence to rank higher yet.
Where the evidence disagrees: 13 of the 19 human studies found no effect.
More Details
Members OnlyBody systems · Combine with · Possible side effects
Body systems: Nervous system, Blood, Metabolism
Combine with: For energy and nerve support, methylcobalamin pairs well with methylfolate (5-MTHF) and vitamin B6 (as P5P) for homocysteine metabolism and methylation, plus a B-complex, iron if deficiency is confirmed, and magnesium. For fast heartburn relief, a separate product is needed, such as calcium carbonate or magnesium/aluminum hydroxide antacids, alginate (sodium alginate) formulas that form a protective raft, or a short-term H2 blocker like famotidine as directed. Longer-term digestive support might include DGL licorice, zinc-carnosine, or aloe vera. Those who use acid reducers regularly may benefit from B12, magnesium, and calcium monitoring, so consult a healthcare provider.
Possible side effects: No major side effects reported. One heart disease trial of low-dose B vitamins saw slightly more activity limits from emotional problems.
Supplement Facts
Vitamin B12 1000 mcg
Other ingredients: Microcrystalline Cellulose, Hypromellose (derived from cellulose) capsule, Leucine, Silicon Dioxide.
Directions: Take 1 capsule one to three times daily or as recommended by your health-care practitioner.
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Graded November 5, 2026 by the Reverse Age Lab evidence engine, from human studies, real reviews and our biohacker panel. How we grade. Is this medical advice? No. Rala organizes the published evidence; go over any change with your doctor, especially if you take meds.
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