Liv Journal

NAD+ Supplement Guide: Benefits, Side Effects and How It Works

  • October 2, 2026
  • 3 min read
NAD+ Supplement Guide: Benefits, Side Effects and How It Works

Key Takeaways

  • NAD+ is a coenzyme your cells use to turn the food you eat into usable energy.
  • The enzymes that help maintain your DNA and send signals between cells rely on it too.
  • Your body makes NAD+ from niacin, and most products sold as NAD+ supplements contain a building block your cells turn into NAD+.
  • In a study of healthy adults, plasma NAD+ was lower in people in their early 50s than in people in their 20s.
  • You can get NAD+ from Liv by prescription as an injection, nasal spray or oral drops, and a licensed provider reviews your history before prescribing.

Your cells use NAD+ all day long. Its full name is nicotinamide adenine dinucleotide, and it's a coenzyme: a helper molecule an enzyme needs to do its job.

What Does NAD+ Do in Your Body?

It helps your cells turn food into energy, and it supports the enzymes that maintain your DNA and send signals between cells. More than 400 enzymes need NAD+, more than for any other vitamin-derived coenzyme. Here's where that work shows up.

Feel More in the Tank

Every cell you have converts food into usable energy, and that conversion runs on NAD+. Much of that work moves the energy in carbohydrates, fats and proteins into adenosine triphosphate (ATP), the form of energy your cells spend.

Built to Bounce Back

Your DNA takes small hits every day. The enzymes that repair it spend NAD+ to do the work.

Firing on All Cylinders

Cells coordinate through enzymes that manage stress and signaling. Those enzymes depend on NAD+.

What's Actually in an NAD+ Supplement?

Most products sold as an NAD+ supplement are actually a building block, and your cells make NAD+ from it.

That building block is called a precursor. Niacin, also called vitamin B3, is one. NAD+ is the main active form every tissue makes from the niacin you absorb. Most of what's on the supplement shelf is a precursor too.

Food supplies niacin as well. Poultry, beef and fish provide it mostly as NAD and its close relative NADP. Nuts, legumes and grains provide it mainly as nicotinic acid. Your body can also turn some tryptophan, an amino acid in protein, into NAD.

You'll see three kinds most often:

  • Nicotinic acid and nicotinamide: the two classic niacin forms. The recommended dietary allowance for niacin is 16 mg niacin equivalents for adult men and 14 mg for adult women.
  • Nicotinamide riboside (NR): sold widely as a supplement ingredient.
  • Nicotinamide mononucleotide (NMN): another building block sold as a supplement ingredient.

Some of these building blocks can raise NAD+. In a six-week study of healthy middle-aged and older adults, NAD+ in blood cells was about 60% higher on oral NR than on placebo.

WHERE NAD COMES FROM

Most of the shelf sells a precursor.

  1. Niacin from food, or from a supplement
  2. Converted in the body every tissue does it
  3. NAD the working coenzyme

NAD eaten as NAD is converted to nicotinamide in the gut first, so it arrives as a precursor too.

More than 400 enzymes require NAD: energy from carbohydrates, fats and proteins; genome integrity, gene expression, cell communication.

Mechanism as described in the NIH Office of Dietary Supplements niacin fact sheet for health professionals, cited in the article.

Start with an evaluation

How Does NAD+ Change With Age?

Studies find it lower in older adults. In a study of healthy adults aged 20 to 87, plasma NAD+ was significantly lower in people in their early 50s than in people in their 20s, and levels were lower at older ages across that range. Earlier work in human skin, from newborns to age 77, found NAD+ content lower with age too.

A study average can't tell you much about your own levels, so talk with your provider about what you're hoping for and whether NAD+ is right for you.

NAD+ by Prescription at Liv

Liv's NAD+ is a prescription medicine, and a licensed pharmacy prepares it for you. Before prescribing, a licensed provider reviews your health history and goals, then checks in on you before every refill at no extra cost.

You can choose how you take it. The injection, nasal spray and oral drops all contain NAD+, the same active ingredient. If you have trouble absorbing medicine through your gut, or you'd rather not take another pill, tell your provider. They'll help you choose. For more, see our guides to NAD+ injection dosing and NAD+ IV therapy.

Start with an evaluation

Side Effects and Safety Notes

Side effects depend on the form. If you take more nicotinic acid than your body needs, it can make your skin flush, while nicotinamide doesn't.

Your provider will ask about:

  • Supplements: especially nicotinamide riboside, since your provider may decide not to prescribe NAD+ alongside it.
  • Medicines: list everything you take.

Tell your provider about side effects before changing your dose. For injections, your provider can keep the same strength and prescribe it less often.

What to Bring to Your Evaluation

Bring a list of your current supplements and medicines, especially anything with niacin or NR in it. It also helps to think about what you'd like help with and how you'd prefer to take NAD+. When you're ready, your evaluation is the next step, where a licensed provider reviews your history with you and decides whether NAD+ is right for you.

Frequently Asked Questions

Is an NAD+ supplement the same thing as NAD+?

Usually not. Most products sold under that name supply a building block such as nicotinamide riboside or a niacin form, which your body converts. Even NAD+ taken by mouth is converted to nicotinamide in the gut before it's absorbed.

Is NADH the same as NAD+?

No. NADH is a different molecule from NAD+, so check the ingredient list to see which one a product contains.

Can a supplement raise your NAD+ levels?

Yes, at least one can. Nicotinamide riboside (NR), a common building block, raised NAD+ in blood cells in one study and reached muscle in another.

Healthy middle-aged and older adults had about 60% more NAD+ in their blood cells after six weeks on oral NR than when they took a placebo (Martens et al., 2018). Each person tried both, at the study's amount of 500 mg of NR twice a day.

So the 60% compares NR with placebo, not with each person's starting level. Of the 24 people who finished the study, 21 had their NAD+ measured.

In the second study, 12 older men took NR for three weeks and a placebo in turn. On NR, researchers measured higher levels of NAD+-related molecules in muscle (Elhassan et al., 2019).

Both studies tested NR, a building block taken by mouth, rather than Liv's NAD+ injection, nasal spray or oral drops.

Where does the age finding come from?

It comes from a small study showing that NAD+ levels tend to be lower at older ages. Researchers measured 29 healthy adults ages 20 to 87 once each, in three groups with average ages of about 23, 53 and 77 (Clement et al., 2019). Most were white US adults.

The study's findings describe how NAD+ levels differ by age. It measured levels, not the effect of raising NAD+ on energy, aging or any health outcome, including with Liv's NAD+ products.

Will NAD+ give me more energy?

NAD+ helps cells use energy from food. That describes what NAD+ does inside cells, not a promise of how you'll feel after taking it. Tell your provider about tiredness or other changes so they can review what may be causing them.

Why does niacin make my face flush?

Nicotinic acid, one of the two common niacin forms, can cause flushing in amounts beyond what your body needs. Nicotinamide, the other form, doesn't. Inositol hexanicotinate is sold as "flush free" niacin, but it's a distinct substance that's absorbed less well than either form, so check the ingredient list.

What's the FDA's position on NMN?

It can count as a dietary supplement ingredient. The FDA questioned that in 2022, then changed its position in September 2025 and now says NMN isn't excluded from the dietary supplement definition. Ask your provider before using any supplement alongside a prescription.

What does compounded mean for Liv's NAD+?

A licensed pharmacy mixes your medicine for you, to the prescription your provider writes, rather than in large batches. Compounded medicines aren't FDA-approved, and the FDA doesn't review their safety, effectiveness or quality before they're marketed.

How do I choose between the injection, spray and drops?

All three contain NAD+. Tell your provider which you'd prefer and whether you have trouble absorbing medicine through your gut. They'll review your health history and help you choose.

References

National Institutes of Health, Office of Dietary Supplements. (n.d.). Niacin: Fact sheet for health professionals. Read 2026-08-20; reread 2026-10-23. https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/

Clement, J., Wong, M., Poljak, A., Sachdev, P., & Braidy, N. (2019). The plasma NAD+ metabolome is dysregulated in "normal" aging. Rejuvenation Research, 22(2), 121-130. doi:10.1089/rej.2018.2077. PubMed record checked October 1, 2026. https://pubmed.ncbi.nlm.nih.gov/30124109/

Elhassan, Y. S., Kluckova, K., Fletcher, R. S., Schmidt, M. S., Garten, A., Doig, C. L., et al. (2019). Nicotinamide riboside augments the aged human skeletal muscle NAD+ metabolome and induces transcriptomic and anti-inflammatory signatures. Cell Reports, 28(7), 1717-1728. PubMed record read October 23, 2026. https://pubmed.ncbi.nlm.nih.gov/31412242/

Martens, C. R., Denman, B. A., Mazzo, M. R., Armstrong, M. L., Reisdorph, N., McQueen, M. B., et al. (2018). Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nature Communications, 9(1), 1286. PubMed record checked October 1, 2026. https://pmc.ncbi.nlm.nih.gov/articles/PMC5876407/

Massudi, H., Grant, R., Braidy, N., Guest, J., Farnsworth, B., and Guillemin, G. J. (2012). Age-associated changes in oxidative stress and NAD+ metabolism in human tissue. PLoS ONE, 7(7), e42357. Read 2026-08-20. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0042357

U.S. Food and Drug Administration. (2025). Reinstatement response letter regarding NDI 1247, beta-nicotinamide mononucleotide (NMN). December 2, 2025. Read October 26, 2026. https://www.regulations.gov/document/FDA-2022-S-0023-0068

U.S. Food and Drug Administration. (n.d.). Compounding and the FDA: Questions and answers. Read September 11, 2026. https://www.fda.gov/drugs/human-drug-compounding/compounding-and-fda-questions-and-answers

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