NAD+ / B Complex dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Injectable NAD+ mixed with B12, and sometimes B6, sold as a clinic drip or as a vial for shots under the skin.
Evidence grade for NAD+ / B Complex: Limited. The rule: people have taken it in a published study, but fewer than 100 of them. The sum on this page: 5 completed trials, 34 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 34
- Human studies
- 5
- Found nothing
- 2
Dose
No human dose established
Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose.
5 completed trials, 34 people given it
8 effects reported, 5 unwanted, 3 wanted, by people using it, not a trial
Goal pages: Brain, memory and mood, Ageing and longevity
In plain English
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 studies in people 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 study 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.
What it has been measured to do
Measured in people
Goals NAD+ / B Complex has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Cell energy and mitochondria34 people · 2 studies
- Memory and thinkingno headcount stated · 2 studies · 2 found nothing
What people using it report
Real people telling you what happened to them. Nobody checked it, and the people who post are not a fair sample, so it cannot prove anything works. It is still the best guide on this page to what people actually do with NAD+ / B Complex, what they expect, and what goes wrong. The full account, including the negative reports, is below.
31 of the 36 indexed goals have no study of any kind behind NAD+ / B Complex
No study in people, animals or cells on this page reports a result for these. That does not prove NAD+ / B Complex does nothing for them. It does mean anything you have heard about NAD+ / B Complex and one of these did not come from a study cited here.
Show full evidence
What is NAD+ / B Complex?
Injectable NAD+ mixed with B12, and sometimes B6, sold as a clinic drip or as a vial for shots under the skin. No study has tested the mix. By weight, the B12 barely registers. In a typical 500 mg NAD+ drip with a 1,000 microgram B12 add-on, B12 is about 0.2 percent of the active ingredients. That is roughly one B12 molecule for every thousand NAD+ molecules. The one trial of a vitamin drip against a plain fluid drip (lactated Ringer's) found no clear difference on anything it measured.
Start with the point that runs through every NAD page on this site. Raising a number in the blood is easy to show. Showing that a person is better at something is the hard step. For injected NAD+, nobody has taken that step.
The only published human study of an NAD+ drip measured NAD+ and its breakdown products in the blood and urine of a handful of men, during a six-hour drip. Blood NAD+ did not rise at all for the first two hours. The study measured no benefit of any kind, because that was not what it set out to do.
Adding B12 does not change the math in the buyer's favor. A clinic drip usually runs 250 to 500 mg of NAD+. The B12 add-on is usually 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 weight. At 250 mg, it is about 0.4 percent. Count molecules and 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. That is roughly a thousand to one. Vials for shots under the skin follow the same pattern. NAD+ is often around 100 mg per mL, and methylcobalamin, a form of B12, is at the standard 1,000 micrograms per mL. That is about a hundred to one by weight. Whatever you pay for in an NAD+ and B complex product, it is not the B12.
B12 is where the real evidence sits, and it is narrow. B12 fixes a B12 shortage, and in a shortage the benefit is clear. Outside a shortage, study after study shows it moves the blood test and changes nothing else. In 271 older people with diabetes and borderline low B12, 1,000 micrograms of methylcobalamin a day for 27 months lowered two blood markers, methylmalonic acid and homocysteine, compared with a dummy pill. Their thinking declined at the same rate as the dummy group's. In 279 older people with mild memory trouble and high homocysteine, B vitamins dropped homocysteine from 13.9 to 9.3 micromoles per litre over 24 months. Their thinking declined no slower than the dummy group's. And the OB12 trial tested whether the shot is even needed. It compared B12 tablets with B12 shots for a real shortage, in family doctors' offices, to see if the tablets hold their own. If you are low, fix it. If you are not, this is the clearest example on the site of fixing a number and fixing nothing else.
The mix also has physical problems that single vials do not. Forms of B12 differ a lot in how stable they are. In a head-to-head lab test, methylcobalamin was the least stable of the three. It lost 48 to 76 percent when mixed with other water-soluble vitamins, 70 to 76 percent next to vitamin C (ascorbic acid), and 79 percent at pH 3, which is acidic. Cyanocobalamin was the most stable. Vitamin C is a standard part of the Myers cocktail that NAD+ is often added to. So the most heavily marketed form of B12 is the one most likely to break down in the very bag it is sold in.
When B6 is included, it is almost always pyridoxine hydrochloride. Pyridoxine is the form of B6 tied to more than 50 reported cases of nerve pain since 2014. In lab tests on cells, it was the only B6 form that killed nerve cells, and it blocked the very enzymes B6 is supposed to help. A B complex that does nothing for someone who is not low is not harmless when it holds high-dose pyridoxine.
How does NAD+ / B Complex work?
NAD+ is a helper molecule cells use to make energy. It also feeds enzymes called sirtuins, PARPs and CD38. Levels in tissue fall with age, and that is the whole basis of the marketing. B12 helps two enzymes do their jobs, which is why fixing a shortage lowers homocysteine and methylmalonic acid. B6, in its active form, helps the body process protein building blocks. The three are mixed on the idea that energy pathways in cells add up. Nobody has tested that idea. And nobody has even suggested a way B12 would help NAD+ get where it is going, or the other way round.
What have studies in people found about NAD+ / B Complex?
There is real human evidence for fixing a B12 shortage. There is one human study of an NAD+ drip that only described blood chemistry and measured no benefit. There is one trial of a vitamin drip against a plain fluid drip, and the vitamins did not win. There is nothing at all on NAD+ mixed with B vitamins.
- NAD+ by drip over six hours: blood NAD+ did not rise for the first two hours. Nobody measured any benefit.
- Myers cocktail versus a plain fluid drip (lactated Ringer's), in 34 adults with fibromyalgia, for eight weeks: no clear difference between the groups on anything measured, at eight or sixteen weeks.
- Methylcobalamin, a form of B12, at 1,000 micrograms a day for 27 months, in 271 older people with diabetes and borderline low B12: two blood markers, methylmalonic acid and homocysteine, fell. Thinking declined at the same rate as on a dummy pill.
- B vitamins for 24 months, in 279 people with mild memory trouble: homocysteine fell from 13.9 to 9.3 micromoles per litre. Thinking declined at the same rate as on a dummy pill.
- OB12 compared B12 tablets with B12 shots for a real shortage, in family doctors' offices, to see if the tablets hold their own. That asks 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+ with B12 or B6 by any route. Nobody has measured what the mix does to anyone, or checked what the three do to each other in a bag. The B12 trials above used pills. So they show that fixing the marker does not fix thinking. They do not show that the shot itself fails. The NAD+ study was blood chemistry in about six men. Anyone quoting an energy or anti-aging benefit for this drip is quoting nothing.
What do people who took NAD+ / B Complex report?
This is what real people say happened to them, good and bad. Nobody measured it. A report cannot tell a real effect from the lift people get just from expecting it to work, from a diet or training change made at the same time, or from what was really in the vial. We still put it near the top. It is the next best thing to a study in people: what happens when real people use it, including what goes wrong.
- A lift in energy and mood for a day or two after a drip. This is the most common report. The fibromyalgia trial suggests people report the same thing after a plain fluid drip (lactated Ringer's).
- Feeling clearer or calmer.
- People who are truly low on B12 describe a real, lasting change in tiredness. That is a different situation from everyone else on this list.
- Chest tightness, cramping, flushing and nausea during the NAD+ part of the drip. Clinics handle it by slowing the drip down. This is the effect people are least ready for.
- Headache and feeling lightheaded.
- A sore red lump where a shot under the skin went in, and a deep ache from B12 shots into the muscle.
- Tingling or numbness in the hands and feet when high-dose B6 is included. Nerve damage from pyridoxine is on record in medical papers, not just on forums.
- A high, repeating cost for a treatment with no measured result. This is the complaint that shows up most once the novelty wears off.
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.
The state of the research
This site's view on the whole NAD family is that raising a blood level is the easy half of the job, and the half that gets sold. NAD+ with B12 is the purest example, because it stacks two things that are easy to measure and hard to turn into a real result. NAD+ goes up somewhere, eventually. B12 goes up reliably. Neither has been shown to make a person who is not low better at anything.
The B12 half is worth pulling apart carefully, because it is the one part here with real, undisputed value. If your B12 is low, fixing it matters, and the evidence for that is old and solid. That is a blood-test question with a blood-test answer. You answer it before you buy anything, not after. Two separate long trials show what happens when you fix the marker in people who are not truly low. The marker moves. Nothing else does.
The mix also brings two physical problems. Methylcobalamin, the form marketed as the better one, is the least stable of the three B12 forms in lab tests. It breaks down badly next to vitamin C, which is in most of the drip bags it gets added to. And where B6 is in the mix, it is pyridoxine, the one form of B6 with a known nerve damage signal at high doses. Someone taking an injectable B complex they do not need is not at zero risk. They carry the pyridoxine risk for no benefit.
The evidence, in charts
Fig. 1a · how many people
34people, across 1 study in people cited here
| Study | People | Share |
|---|---|---|
| Journal of Alternative and Complementary Medicine 2009 | 34 | 100% |
The whole total is one study of 34. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 4 more studies in people give no headcount and are not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
5 of 8 sources here are studies in people. The rest are not.
- Study in people · done in people563%
- Lab (cells in a dish) · cells or tissue225%
- Review of studies · sums up other studies113%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
The studies cover 5 different years, 2009 to 2020, counted from the list of sources on this page. The newest source on file is from 2020, more than five years ago. Research on it 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, by prescription in 0, not approved in 3. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Blend
- Molecule weight
- Mixture; NAD+ 663.4 Da, vitamin B12 1,355.4 Da
- Half-life
- Stated in words, not a numbersee the exact wording below
- Chain length
- None on file
Half-life as stated on file: Not one number. The two parts leave the body on completely different timescales, one within hours and the other held in the liver for months.
No amino acid sequence is on file for NAD+ / B Complex, which is expected: a blend is not built from amino acids.
Fig. 6 · what is in the vial
We cannot show how much of each is in this blend
Sellers do not agree on a vial size for NAD+ with B-complex, so nobody outside can know how much of each ingredient is in it. Splitting the bar evenly would make up the very number this page is here to question.
- NAD+Limited. People have taken it in a published study, but fewer than 100 of them. 1 completed trial, none stating how many people.amount not stated
- Vitamin B12Limited. People have taken it in a published study, but fewer than 100 of them. 2 completed trials, none stating how many people.amount not stated
Ingredient list from the product labels we have. Amounts are what the label says is in the vial, never a dose.
The studies we cite
- Study in people2019A Pilot Study Investigating Changes in the Human Plasma and Urine NAD+ Metabolome During a 6 Hour Intravenous Infusion of NAD
The first look at NAD+ given by drip in people, and it measured chemistry rather than benefit. Blood was sampled through a six hour infusion. Nothing rose in the blood for the first two hours, which suggests the body takes it up or breaks it down quickly. Nobody was tested for energy, thinking, sleep or anything else a clinic sells this for. No B vitamins were given. This is a starting point for researchers, not evidence that a drip does anything for you.
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.
- Study in people2009Intravenous micronutrient therapy (Myers' Cocktail) for fibromyalgia: a placebo-controlled pilot study
The vitamin drip did not beat salt water. Thirty four adults with fibromyalgia were given either the vitamin mixture or a plain fluid drip every week for two months. Both groups felt better. Neither group felt better than the other, at two months or at four. Sitting for an hour with a needle in your arm does something on its own, and that is what this trial measured. It is the closest thing to a controlled test of the drip NAD+ is sold alongside.
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.
- Study in people2017A randomized placebo controlled trial of vitamin B12 supplementation to prevent cognitive decline in older diabetic people with borderline low serum vitamin B12
The blood test improved and the person did not. Two hundred and seventy one older people with diabetes and borderline low B12 took a high dose of it, or a dummy, for over two years. Two blood markers of B12 shortage dropped, exactly as they should. Thinking and memory declined at the same rate in both groups. This is the whole trap with B12. The number on the report moves and nothing you would notice moves with it.
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.
- Study in people2020A randomized placebo-controlled trial of using B vitamins to prevent cognitive decline in older mild cognitive impairment patients
The same lesson again, in people already losing their memory. Two hundred and seventy nine older adults with mild memory trouble took B12 with folic acid, or a dummy, for two years. Homocysteine, the blood marker the whole theory hangs on, fell by about a third. Their decline in thinking was no slower than the dummy group's. Fixing the marker protected nobody. Two trials now say the same thing, which makes it hard to put down to bad luck.
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.
- Study in people2020Oral versus intramuscular administration of vitamin B12 for vitamin B12 deficiency in primary care: a pragmatic, randomised, non-inferiority clinical trial (OB12)
This trial asks whether the injection is needed at all. It set B12 tablets against B12 shots in ordinary general practice, in people with a genuine shortage. It was built to test whether the tablets hold their own, not to show the shots are better. The question matters, because real deficiency is the one place B12 unquestionably works. If swallowing it is enough even there, the clinic injection has little left to justify it. Our summary records the design and not the result.
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.
- Review of studies2013Clinical practice. Vitamin B12 deficiency
A standard doctors' guide to finding and treating a B12 shortage, with pills or shots. It covers the one situation where B12 shots clearly help.
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.
- Lab (cells in a dish)2020Sorbitol enhances the physicochemical stability of B(12) vitamers
In a lab. Three forms of B12 were tested for how well they hold up against heat, light, acid and other vitamins. Methylcobalamin, the form sold as the best one, broke down the most. Cyanocobalamin held up best. Vitamin C, which broke it down, is a routine part of the drips NAD+ is added to.
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.
- Lab (cells in a dish)2017The vitamin B6 paradox: Supplementation with high concentrations of pyridoxine leads to decreased vitamin B6 function
Case reports in people, then tests in a dish. More than 50 people reported nerve pain from B6 supplements after 2014. In lab tests on nerve and gut cells, only one form of B6, pyridoxine, killed cells, and it blocked the enzymes B6 is meant to help. Pyridoxine is the form in most injectable B complex products.
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.
Where to buy NAD+ / B Complex
No seller we track lists NAD+ / B Complex yet. We read sellers’ public product lists every week, and this section fills in as soon as one does. Every seller, graded
Common questions
Has NAD+ / B Complex been tested in people?
Yes. 34 people given it across 5 completed trials cited here, 2 of which found nothing. Injectable NAD+ mixed with B12, and sometimes B6, sold as a clinic drip or as a vial for shots under the skin.
What is the NAD+ / B Complex dosage?
No human dose established. Amounts that were given in studies sit in Human evidence on this page. None of them is a personal dose. 5 completed trials, 34 people given it
Is NAD+ / B Complex FDA-approved?
Not approved as a blend. B12 shots are approved for B12 deficiency. NAD+ is not an approved drug. It reaches patients through pharmacy mixing and drip (IV) clinics.
Has anyone tested NAD+ with B12 together?
No. There is no published trial of the mix, by any route, in anyone. What exists is one human study of an NAD+ drip that described blood chemistry and measured no benefit. Separately, there is a large body of research on fixing a B12 shortage.
How much B12 am I actually getting relative to the NAD+?
Almost none, by comparison. A 500 mg NAD+ drip with a 1,000 microgram B12 add-on is about 0.2 percent B12 by weight. 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+?
Maybe, and there is no way to tell from how you feel. The one trial of a vitamin drip against a plain fluid drip found that people on the plain fluid (lactated Ringer's) got better too. The difference between the vitamins and the plain fluid was not clear on any measure. An hour in a chair with a line in, plus fluid, plus expecting to feel better, does something on its own.
Will B12 shots fix my fatigue?
If you are truly low, yes. That is a real, well-documented benefit. If you are not, here is the honest answer. Two long trials fixed the blood markers in people with borderline or low-normal B12, and changed nothing anyone could measure. Check your blood first. That answer costs one blood draw, not a monthly membership.
Is methylcobalamin better than cyanocobalamin?
It is marketed that way. In a head-to-head stability test, it was the least stable of the three forms. It lost 48 to 76 percent when mixed with other water-soluble vitamins, and 79 percent at pH 3. Cyanocobalamin was the most stable. In a mixed drip bag with vitamin C, the form sold as better is the one most likely to have broken down.
Should I worry about the B6 in a B complex blend?
If the dose is high, yes. This is the specific risk in this product that nobody selling it brings up. More than 50 cases of nerve pain from B6 supplements were reported after 2014. In lab tests on cells, the form to blame was pyridoxine, which is what injectable B complex products use. You carry that risk for an ingredient 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 one out. In a pre-mixed vial for shots under the skin, no. That is the repeat cost of every blend on this site. The split is fixed before you get it. If something goes wrong, you cannot take out one part to find out what caused it.