NAD+ / B Complex
Injectable NAD+ blended with vitamin B12 and sometimes B6
Written by Aaron CuhaReviewed Sep 2026
Also known as: NAD+ with B12, NAD B complex drip, NAD+ energy shot
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
This is NAD+ mixed with vitamin B12, and sometimes B6. Clinics sell it as a drip. Some places sell it as a shot you do at home. NAD+ is a helper molecule your cells use to make energy. B12 is a vitamin you need. The pitch is more energy. Nobody has ever tested the mix.
What people take it for
- More energy and less brain fog.
- Slowing down ageing.
- Getting over a hangover or a hard week.
- Fixing a low B12 number on a blood test.
What the trials actually showed
Start with the size of each part. A drip holds 250 to 500 mg of NAD+. The B12 add on is 1,000 micrograms, which is 1 mg. So the B12 is about a fifth of one percent of what is in the bag. Count molecules and it is worse. There is roughly one B12 for every thousand NAD+. Whatever you are paying for, it is not the B12. Now the NAD+. There is one human study of the drip. It only watched blood and urine. For the first two hours the blood level did not even go up. It measured no benefit at all, because it never set out to. No trial has shown a drip helps energy, thinking or ageing. Now the B12. This part has real evidence and it is narrow. If you are low, fixing it helps, and that is not in doubt. If you are not low, look at what happened. 271 older people with a borderline number took B12 for 27 months. Their blood markers got better. Their thinking did not. 279 more people took B vitamins for two years. Homocysteine dropped from 13.9 to 9.3. Thinking did not change. And the one real test of a vitamin drip against plain fluid: 34 people, eight weeks, no clear difference on anything. Two more problems come from mixing. The fancy form of B12 is the least stable one. Put it next to vitamin C and 70 to 76 percent of it breaks down. Vitamin C is in most of these bags. And the B6 in a B complex is the form tied to more than 50 reported cases of nerve pain since 2014.
What people report
Reports, not trial results
The good
- A lift in energy for a day or two after a drip.
- Feeling clearer and calmer.
- People who really are low on B12 saying their fatigue lifted and stayed lifted. That is a different story from everyone else here.
The bad
- Chest tightness, cramping and nausea during the NAD+ part. Clinics slow the drip down to deal with it. This is the one people do not see coming.
- Flushing, headache and feeling lightheaded.
- A sore red lump from the shot, or a deep ache from a B12 shot in the muscle.
- Tingling or numb hands and feet if there is a lot of B6 in the mix. That one is in the medical literature, not just on forums.
- The bill. This is the complaint that shows up most once the novelty wears off.
Where these come from: The drip reactions and the price gripes come from IV clinic write ups and user forums. None of it is from a trial. The nerve pain from B6 comes from published case reports. The fibromyalgia trial that pitted a vitamin drip against plain fluid is the only real comparison on this page, and it is why the post drip lift is a report and not a finding.
My bottom line
Getting a number in your blood to go up is not a result. Check your B12 with a blood draw, and if it is low, fix it, which costs almost nothing. The rest of this bag has never been shown to do anything for a healthy person, and I would not sit in the chair for it.
An opinion, not a finding. I am a coach, not a doctor.
Overview
Injectable NAD+ blended with B12 and sometimes B6, sold as a clinic drip or a subcutaneous vial. No study has tested the combination. By mass the B12 is a rounding error: at a typical 500 mg NAD+ drip with a 1,000 microgram B12 add-on, the B12 is about 0.2 percent of the active ingredient, roughly one B12 molecule for every thousand NAD+ molecules. The one placebo-controlled trial of an intravenous vitamin cocktail found no significant difference from lactated Ringer's on any outcome.
Start with the same point that governs every NAD page on this site. Raising a number in blood is easy to demonstrate. Showing that a person is better at something is the hard step, and for injected NAD+ that step has not been taken. The only published human study of an NAD+ infusion measured the plasma and urine NAD+ metabolome during a six-hour drip in a handful of men. Plasma NAD+ did not rise at all for the first two hours. The study measured no benefit of any kind, because measuring a benefit was not what it set out to do.
Blending B12 into that does not change the arithmetic in the buyer's favour. A clinic drip typically runs 250 to 500 mg of NAD+, and the B12 add-on is typically 1,000 micrograms, which is 1 mg. At 500 mg of NAD+ the B12 is 1 part in 501, about 0.2 percent of the active mass; at 250 mg it is about 0.4 percent. By molecule count it is starker: NAD+ weighs 663.4 Da and B12 weighs 1,355.4 Da, so 500 mg of NAD+ is about 754 micromoles against 0.74 micromoles of B12, roughly a thousand to one. Subcutaneous blend vials follow the same pattern, with NAD+ commonly around 100 mg per mL and methylcobalamin at the standard injectable strength of 1,000 micrograms per mL, about a hundred to one by mass. Whatever you are paying for in an NAD+ and B complex product, it is not the B12.
B12 is where the real evidence sits, and the real evidence is narrow and specific. It corrects deficiency, and in deficiency the benefit is unambiguous. Outside deficiency it has repeatedly been shown to move the blood marker and change nothing else. In 271 older diabetic outpatients with borderline low B12, 27 months of methylcobalamin at 1,000 micrograms daily significantly lowered methylmalonic acid and homocysteine against placebo and produced no difference in cognitive decline. In 279 older people with mild cognitive impairment and raised homocysteine, B vitamins dropped homocysteine from 13.9 to 9.3 micromoles per litre over 24 months with no significant difference in cognitive decline. And the OB12 trial tested the premise of the injection itself, comparing oral with intramuscular B12 for deficiency in primary care as a non-inferiority trial. If you are deficient, correct it. If you are not, this is the clearest worked example on the site of fixing a number and fixing nothing else.
The blend also has physical problems that single vials do not. B12 vitamers differ sharply in stability. In a controlled comparison, methylcobalamin was the least stable of the three, losing 48 to 76 percent in the presence of other water-soluble vitamins, 70 to 76 percent alongside ascorbic acid, and 79 percent at pH 3; cyanocobalamin was the most stable. Ascorbic acid is a standard component of the Myers cocktail that NAD+ is routinely added to, so the most marketed form of B12 is the one most likely to degrade in the bag it is sold in. Where B6 is included it is almost always pyridoxine hydrochloride, and pyridoxine is the specific vitamer implicated in more than 50 reported cases of sensory neuronal pain since 2014; in cell work it was the only B6 form that killed neurons and it inhibited the very enzymes B6 is supposed to serve. A B complex that is doing nothing for a replete person is not neutral when it contains high-dose pyridoxine.
Mechanism of action
NAD+ is a redox coenzyme and the substrate for sirtuins, PARPs and CD38. Tissue levels decline with age, which is the entire basis of the marketing. B12 is a cofactor for methionine synthase and methylmalonyl-CoA mutase, which is why correcting deficiency lowers homocysteine and methylmalonic acid. B6 in its active pyridoxal-5-phosphate form is a cofactor in amino acid metabolism. The three are combined on the assumption that cellular energy pathways are additive, an assumption nobody has tested, and there is no proposed mechanism by which B12 improves NAD+ delivery or the reverse.
Human evidence
There is real human evidence for correcting B12 deficiency, a single descriptive human study of an NAD+ infusion that measured no benefit, one placebo-controlled trial of an intravenous vitamin cocktail that did not beat saline, and nothing at all on NAD+ blended with B vitamins.
- Intravenous NAD+, six-hour infusion: plasma NAD+ did not rise for the first two hours. No efficacy outcome was measured.
- Myers cocktail versus lactated Ringer's, 34 adults with fibromyalgia, eight weeks: no statistically significant difference between groups on any outcome at eight or sixteen weeks.
- Methylcobalamin 1,000 micrograms daily for 27 months, 271 older diabetic people with borderline low B12: methylmalonic acid and homocysteine fell significantly, cognitive decline was unchanged.
- B vitamins for 24 months, 279 people with mild cognitive impairment: homocysteine fell from 13.9 to 9.3 micromoles per litre, cognitive decline was unchanged.
- OB12 tested oral against intramuscular B12 for genuine deficiency in primary care as a non-inferiority trial, which is the question of whether the shot is needed at all.
What this does not tell you: Not one of these studies used the product being sold. No published trial has given NAD+ together with B12 or B6 by any route, measured what the combination does to anyone, or checked what the three do to each other in solution. The B12 trials above are oral, so they establish that correcting the marker does not fix cognition, not that the injection specifically fails. The NAD+ study was six men-worth of metabolomics. Anyone quoting an energy or anti-ageing benefit for this drip is quoting nothing.
Reading the research record
This site's position on the whole NAD family is that raising a blood metabolite is the easy half of the job and the half that gets sold. NAD+ with B12 is the purest example of that pattern, because it stacks two things that are both easy to measure and hard to convert into an outcome. NAD+ goes up somewhere, eventually, and B12 goes up reliably, and neither has been shown to make a replete person better at anything.
The B12 half is worth separating out carefully, because it is the one component here with genuine, uncontested value. If your B12 is low, correcting it matters and the evidence for that is old and solid. That is a blood-work question with a blood-work answer, and it is answered before you buy anything, not after. Two separate long randomised trials show what happens when you correct the marker in people who are not truly deficient: the marker moves, the outcome does not.
The blend also introduces two physical problems. Methylcobalamin, the form marketed as the superior one, is measurably the least stable of the three B12 vitamers and degrades badly in the presence of ascorbic acid, which is in most of the infusion bags these are added to. And where B6 is in the mix it is pyridoxine, the one vitamer with a documented neuropathy signal at high intake. A person taking an injectable B complex they do not need is not at zero risk; they are carrying the pyridoxine risk for no benefit.
The evidence, charted
Fig. 1 · evidence composition
5of 8 citations (63%) are in people
Counted from the citation list on this page. The Human count is the same number shown in the badge at the top. Both understate any literature larger than the sources we cite.
Fig. 2 · evidence over time
Evidence spans 5 distinct years, 2009 to 2020, counted from the citation list on this page. The newest citation on file is from 2020, more than five years ago; the published record may have gone quiet.
Fig. 3 · legal status at a glance
US
Approved
UK
Not approved
AU
Not approved
CA
Not approved
Approved in 1 of 4, prescription route in 0, not approved in 3. A jurisdiction's classification is a regulatory fact, not a verdict on the science; see Legal status below for the full text and any notes.
Fig. 4 · dose response
No human dose response curve exists
We draw this figure where the data supports it. For this compound in humans it does not, so the panel stays empty rather than borrowing an animal curve and implying it transfers.
Key studies & citations
- Human2019
A Pilot Study Investigating Changes in the Human Plasma and Urine NAD+ Metabolome During a 6 Hour Intravenous Infusion of NAD
The first human data on intravenous NAD+. Plasma NAD+ and its metabolites did not rise during the first two hours of the infusion, consistent with rapid tissue uptake or breakdown. The study measured the metabolome only. No efficacy outcome of any kind was assessed, and no B vitamins were given.
Frontiers in Aging Neuroscience - Human2009
Intravenous micronutrient therapy (Myers' Cocktail) for fibromyalgia: a placebo-controlled pilot study
34 adults with fibromyalgia randomised to weekly infusions of the Myers cocktail or to lactated Ringer's solution for eight weeks. Both groups improved, but there was no statistically significant difference between them on any outcome at eight or sixteen weeks. This is the closest thing to a controlled trial of the intravenous vitamin cocktail that NAD+ is sold alongside, and it did not beat saline.
Journal of Alternative and Complementary Medicine - Human2017
A randomized placebo controlled trial of vitamin B12 supplementation to prevent cognitive decline in older diabetic people with borderline low serum vitamin B12
271 diabetic outpatients aged 70 or over with plasma B12 between 150 and 300 pmol per litre took methylcobalamin at 1,000 micrograms daily or placebo for 27 months. Serum methylmalonic acid and homocysteine fell significantly against placebo at months 9 and 27. There was no significant difference in cognitive decline at month 27. The blood marker moved and the outcome did not.
Clinical Nutrition - Human2020
A randomized placebo-controlled trial of using B vitamins to prevent cognitive decline in older mild cognitive impairment patients
279 outpatients aged 65 or over with mild cognitive impairment and raised homocysteine took methylcobalamin at 500 micrograms plus folic acid, or placebo, for 24 months. Homocysteine fell from 13.9 to 9.3 micromoles per litre. There was no significant difference in cognitive decline at 24 months. A second worked example of the same lesson.
Clinical Nutrition - Human2020
Oral versus intramuscular administration of vitamin B12 for vitamin B12 deficiency in primary care: a pragmatic, randomised, non-inferiority clinical trial (OB12)
Multicentre pragmatic non-inferiority randomised trial in primary care comparing oral with intramuscular B12 for genuine deficiency. This is the design that asks whether the injection a wellness clinic sells is necessary even for the one indication where B12 unambiguously works.
BMJ Open - In vitro2020
Sorbitol enhances the physicochemical stability of B(12) vitamers
Direct comparison of cyanocobalamin, hydroxocobalamin and methylcobalamin under heat, UV, pH and co-existing vitamins. Methylcobalamin was the least stable, losing 48 to 76 percent alongside other water-soluble vitamins, 70 to 76 percent with ascorbic acid and 79 percent at pH 3; cyanocobalamin was the most stable. Ascorbic acid is a routine component of the infusions NAD+ is added to.
International Journal for Vitamin and Nutrition Research - In vitro2017
The vitamin B6 paradox: Supplementation with high concentrations of pyridoxine leads to decreased vitamin B6 function
More than 50 cases of sensory neuronal pain from vitamin B6 supplementation were reported after 2014. In neuronal and intestinal cell lines, pyridoxine was the only B6 vitamer that caused concentration-dependent cell death, raised Bax and caspase-8, and inhibited two pyridoxal-5-phosphate dependent enzymes. Pyridoxine hydrochloride is the form used in most injectable B complex preparations.
Toxicology in Vitro - Review2013
Clinical practice. Vitamin B12 deficiency
Standard clinical review of how B12 deficiency is diagnosed and treated, including both oral and parenteral replacement. The reference point for the only situation in which injectable B12 has clear, uncontested benefit.
New England Journal of Medicine
What users report
Self-reported experiences, not evidence. Nothing below was measured under controlled conditions, and reports like these cannot separate a real effect from placebo, from the training or diet change that accompanied it, or from what the product actually contained. They are here because knowing what people describe, including what goes wrong, is worth reading alongside the studies.
- A lift in energy and mood for a day or two after a drip, which is the most common report and which the fibromyalgia trial suggests is also what people report on lactated Ringer's.
- Feeling clearer or calmer.
- People genuinely low on B12 describing a real and lasting change in fatigue, which is a different situation from everyone else in this list.
- Chest tightness, cramping, flushing and nausea during the NAD+ portion of the drip, which clinics manage by slowing the infusion rate. This is the effect people are least prepared for.
- Headache and lightheadedness.
- A sore red lump at a subcutaneous injection site, and a deep ache from intramuscular B12.
- Tingling or numbness in the hands and feet where a high-dose B6 component is included. Pyridoxine neuropathy is documented in the literature, not just on forums.
- A high recurring cost for a treatment with no measured outcome, which is the complaint that shows up most often once the novelty passes.
Sources: The infusion reactions and the price complaints come from IV clinic write-ups and user forums and are not trial data. The B6 neuropathy signal comes from published case reports and from the cell work cited on this page. The fatigue improvement in genuine deficiency comes from clinical literature. The Myers cocktail trial is the only controlled comparison here, and it is the reason to treat the post-drip lift as unproven rather than as a finding.
Frequently asked questions
Has anyone tested NAD+ with B12 together?
No. There is no published trial of the combination by any route, in anyone. What exists is one descriptive human study of an NAD+ infusion that measured no benefit, and a large separate literature on correcting B12 deficiency.
How much B12 am I actually getting relative to the NAD+?
Almost none, proportionally. A 500 mg NAD+ drip with a 1,000 microgram B12 add-on is about 0.2 percent B12 by mass. By molecule count it is roughly one B12 for every thousand NAD+. Whatever the drip is doing or not doing, the B12 is not the part you are paying for.
I feel great after a drip. Is that the NAD+?
Possibly, and there is no way to tell from feeling it. The one placebo-controlled trial of an intravenous vitamin cocktail found that people on lactated Ringer's improved too, and the difference between the cocktail and the saline was not statistically significant on any measure. An hour in a chair with a line in, plus fluid, plus expectation, is an active intervention on its own.
Will B12 shots fix my fatigue?
If you are genuinely deficient, yes, and that is a real and well-documented benefit. If you are not, the honest answer is that two long randomised trials corrected the blood markers in people with borderline or low-normal B12 and changed nothing measurable. Check the blood first. That answer costs a blood draw, not a monthly membership.
Is methylcobalamin better than cyanocobalamin?
It is marketed that way. In a direct stability comparison it was the least stable of the three forms, losing 48 to 76 percent in the presence of other water-soluble vitamins and 79 percent at pH 3, while cyanocobalamin was the most stable. In a mixed infusion bag containing vitamin C, the form sold as superior is the one most likely to have degraded.
Should I worry about the B6 in a B complex blend?
If the dose is high, yes, and this is the specific risk in this product that nobody selling it raises. More than 50 cases of sensory nerve pain from B6 supplementation were reported after 2014, and in cell work the responsible form was pyridoxine, which is what injectable B complex preparations use. You are carrying that risk for a component you probably do not need.
Can I have the NAD+ without the B vitamins, or the other way round?
In a drip, yes, because the clinic mixes the bag and can leave a component out. In a pre-mixed subcutaneous vial, no. That is the recurring cost of every blend on this site: the ratio is fixed before you get it, and if something goes wrong you cannot remove one part to find out what caused it.