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NAD+ vs. AG1: Separating the Science from the Hype
Fishtown Medicine•6 min read
4.96 (124)

NAD+ vs. AG1: Separating the Science from the Hype

Ashvin Vijayakumar MD

Medically Reviewed

Ashvin Vijayakumar MD•Updated May 2, 2026
On This Page
  • Why We Look Past the Marketing
  • What Is NAD+ and Does It Help?
  • What About AG1 (Athletic Greens)?
  • How Do We Decide What Goes in Your Stack?
  • Guidance from the Clinic
  • Actionable Steps in Philly
  • Common Questions
  • Is NR better than NMN?
  • Can I just eat nutritional yeast for NAD+?
  • Does AG1 replace a multivitamin?
  • How fast does NAD+ supplementation work?
  • Do I need to test my NAD+ levels?
  • Is NAD+ safe for everyone?
  • Can I get NAD+ from food?
  • Why is AG1 so popular if the dosing is hidden?
  • Deep Questions
  • How do NAD+ supplements interact with my medications?
  • Are there contraindications to NAD+ therapy?
  • Can I take NAD+ while pregnant or breastfeeding?
  • How do NAD+ supplements affect biological age?
  • Are NAD+ patches and skin creams effective?
  • How does NAD+ compare with creatine for cognitive support?
  • What about flushing or itchiness from niacin?
  • Can children or teens take NAD+ supplements?
  • How do I evaluate a "greens" powder if I still want one?
  • Are there any risks of taking too much NAD+?
  • Can I cycle NAD+ supplementation?
  • How does NAD+ fit into a Medicine 3.0 longevity plan?
  • What does NAD+ therapy cost in Philadelphia?
  • How do I tell a quality supplement brand from a marketing brand?
  • Should I trust podcast sponsors and influencer recommendations?
  • Scientific References

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TL;DR30-second take

NAD+ supplements (mostly NR or NMN, two precursors that raise cellular NAD+ levels) have human data behind them and may support energy and DNA repair as we age. AG1 is essentially a premium multivitamin with hidden doses inside proprietary blends. NAD+ is a targeted tool. AG1 is convenience marketing.

Why We Look Past the Marketing

In the supplement world, marketing budgets often dwarf research budgets. We look closely at two of the most popular "Medicine 3.0" products, NAD+ boosters and greens powders, to figure out which one changes your biology.

If you listen to wellness podcasts, you have heard about Athletic Greens (AG1) and NAD+. They are sold as essential insurance policies for your health. One promises to cover your nutrition. The other promises to slow aging.

At Fishtown Medicine, we look past the endorsements at the clinical data. The goal is to help you spend your supplement budget on the things that help your body.

What Is NAD+ and Does It Help?

Verdict: Good science, complicated delivery.

NAD+ stands for nicotinamide adenine dinucleotide. It is a coenzyme (a small molecule that helps enzymes run) found in every living cell. It does two big jobs.

  1. Energy production. It helps turn food into ATP (the cell's fuel currency) inside the mitochondria.
  2. DNA repair. It powers sirtuins (a family of longevity-related enzymes) and PARPs (proteins that repair damaged DNA).

The problem. NAD+ levels drop by roughly 50% as we age. That energy slump is one of the well-documented hallmarks of aging.

The solution? You cannot just swallow NAD+. It gets broken down in the gut. You either use a precursor (a building block that the body converts into NAD+) or get it intravenously.

  1. Nicotinamide riboside (NR). Backed by human clinical trials (Brenner, Martens) showing it raises NAD+ in healthy adults.
  2. Nicotinamide mononucleotide (NMN). Popularized by David Sinclair. Strong mouse data, growing human data, and an evolving FDA legal status.
  3. IV NAD+. 100% bioavailability. Patients often report mental clarity and steady energy. It is expensive and uses a needle.

Our take. NAD+ restoration is a legitimate longevity strategy. Oral delivery is tricky. We use NR for daily support and reserve IV for clearer repletion needs.

What About AG1 (Athletic Greens)?

Verdict: An expensive, well-marketed multivitamin.

AG1 is a daily nutrition powder with about 75 ingredients (vitamins, minerals, probiotics, adaptogens). On the surface, it looks like it covers everything.

The problems.

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  1. Proprietary blends. They hide the dose of each ingredient inside grouped blends. You cannot tell whether you are getting a therapeutic dose of ashwagandha or a sprinkle.
  2. Bioavailability conflicts. Mixing 75 ingredients in one scoop creates competition for absorption. Zinc and copper, for example, fight each other.
  3. Cost. At about $100 per month, you are paying a premium for marketing and convenience rather than for higher potency.

Our take. AG1 is a premium multivitamin with greens flavor. It is better than a nutrient-poor diet, but it should not replace whole vegetables or targeted, clinical-grade supplements when a deficiency is present.

  • Better strategy. Eat whole food, test for specific deficiencies, and if you are low in magnesium, take a clinical-grade magnesium product rather than a shotgun blend.

How Do We Decide What Goes in Your Stack?

We sort interventions by purpose: fixing a deficit vs. insuring against a poor diet.

InterventionGoalMechanismFishtown Strategy
NAD+ (NR)Mitochondrial repair.Replenishes a coenzyme that fuels DNA repair.Yes. Used for fatigue, brain fog, and longevity.
AG1Nutritional insurance.Broad-spectrum, low-dose micronutrients.Optional. Whole foods first. Supplement specific deficits if needed.
Vitamin D3Immune and bone support.Hormone precursor needed for many systems.Yes, but test levels first. Do not guess.
CreatineCellular energy.Recycles ATP for brain and muscle.Yes. The cheapest, most effective brain and muscle supplement available.

Guidance from the Clinic

Dr. Ash
"I encourage my patients not to rely on powders for their health. Vitality comes from dense, whole foods. I do support tools like NAD+ that food cannot deliver in big enough doses to address an age-related drop."

We have your back. At Fishtown Medicine, we do more than order tests and hand you a result. We interpret, explain, and advocate.

Actionable Steps in Philly

Spend on diagnostics rather than shotgun powders. Know what you are missing, then fix it.

  1. Audit your stack. Be cautious of proprietary blends that hide doses.
  2. Test, do not guess. A micronutrient panel (such as SpectraCell) can show whether you are truly low in B12, zinc, or magnesium.
  3. Focus on energy first. If you are over 40 and chronically fatigued, ask whether an NAD+ plan fits your physiology.

At Fishtown Medicine, we do not sell green powders; we use data.

Optimize the machine rather than painting it green.

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Scientific References

  1. Conze D, et al. Safety and metabolism of long-term administration of NIAGEN (nicotinamide riboside chloride) in a randomized, double-blind, placebo-controlled clinical trial of healthy overweight adults. Sci Rep. 2019;9(1):9772.
  2. Martens CR, et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun. 2018;9(1):1286.
  3. Office of Dietary Supplements. Dietary supplements for exercise and athletic performance. NIH Fact Sheet.
  4. Guallar E, et al. Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements. Ann Intern Med. 2013;159(12):850-851.
  5. Yoshino M, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021.
Medical Disclaimer: This resource provides clinical context for educational purposes. In the world of precision medicine, there is no "one size fits all." The right plan must be matched to your unique lab work, physiology, and performance goals. Consult Dr. Ash to determine if this approach is right for you, particularly if you have chronic health conditions or are taking prescription medications.

Frequently Asked Questions

Common Questions

NR has stronger human clinical trial data right now, particularly around safety and bioavailability. NMN looks promising but has fewer published human safety trials and a complicated FDA status. For most patients we use NR until the NMN data catches up.
You can get small amounts of NAD+ precursors from foods like milk, yeast, and some vegetables. The amounts are not enough to reverse age-related declines. Therapeutic doses require a supplement or an IV.
Functionally, AG1 acts like a premium multivitamin. A basic multivitamin costs around $15 per month. AG1 costs around $100 per month. You are paying for greens branding, taste, and podcast advertising rather than a higher dose of nutrients.
Some patients feel a clearer head and steadier energy within a week of starting NR or NMN. Others need 4 to 8 weeks before they notice anything. IV NAD+ produces a faster, stronger sensation, sometimes during the infusion itself.
You can test NAD+ in plasma or red blood cells through specialty labs. Testing is useful when symptoms are clear (chronic fatigue, brain fog) and we want a baseline. For most healthy adults under 50, testing is optional.
NAD+ supplementation has been well tolerated in trials. The main side effects are mild flushing and GI upset. Patients with active cancer should discuss NAD+ carefully with their oncology team because some pathways NAD+ supports are also used by tumor cells.
You cannot meaningfully raise NAD+ through food. Niacin (vitamin B3) and tryptophan are precursors that the body uses to make NAD+, but the doses available in a normal diet are too low to overcome age-related decline. Supplementation closes the gap.
AG1 wins on convenience, taste, and a strong celebrity endorsement strategy. It is also better than skipping nutrition. The popularity does not mean the dosing is therapeutic, only that the product solves a habit problem for many people.

Deep-Dive Questions

NAD+ precursors can have mild interactions with chemotherapy, certain antivirals, and high-dose niacin. Most prescription medications have no meaningful interaction. We always review the full medication list before starting.
Yes. Active cancer (particularly under chemotherapy) is the main relative contraindication, because NAD+ supports cellular processes that some tumors exploit. Severe kidney impairment and pregnancy are also reasons to pause. We screen for these at intake.
We avoid NAD+ supplementation during pregnancy and breastfeeding due to limited safety data. Standard prenatal vitamins, B-complex, and a healthy diet remain the foundation. After breastfeeding, we can re-evaluate.
Early data suggest that NR and NMN may slow aspects of biological aging measured by methylation clocks (the chemical tags on DNA that track age). The data is small and short-term. Many of our patients track biological age alongside NAD+ therapy to see direction over time.
Topical NAD+ products have weaker absorption data than oral or IV. The skin barrier limits how much makes it into circulation. We treat patches as marginal and reserve IV or oral NR for serious goals.
Creatine supports brain energy through phosphocreatine recycling. NAD+ supports broader mitochondrial and DNA repair pathways. Many patients use both. Dollar for dollar, creatine is the cheapest cognitive support tool we know of.
High-dose niacin (an older vitamin B3 form) causes a strong flush. NR and NMN cause much less flushing because they enter the NAD+ pathway differently. If you are sensitive to niacin, NR is usually the better fit.
There is little safety data for NAD+ supplementation in children. We do not recommend NAD+ products for children or teens outside of a specialist setting. Adolescents with chronic fatigue should be evaluated for sleep, mental health, and nutrient deficiencies first.
Look for transparent dosing (no proprietary blends), third-party testing (NSF or USP certification), and a short ingredient list. Skip products that promise to do everything for everyone. A well-formulated greens powder is a fine convenience tool when whole vegetables are not realistic.
NAD+ supplements at standard doses (300 to 1000 mg of NR per day) are well tolerated. At very high doses, methyl-group depletion (the body running short of compounds it uses to recycle and clear NAD) is a theoretical concern. We sometimes pair higher doses with TMG (a methyl donor) to support balance.
Some patients use NAD+ in 8 to 12 week cycles, then take a 2 to 4 week break. The data on cycling is thin. Daily use is also reasonable for most adults. We choose based on symptoms, labs, and the rest of the plan.
NAD+ is one piece of a layered plan that includes sleep, training, ApoB, fasting insulin, hormones, and stress management. We treat it as a tool for the right person rather than a foundation. Foundations come first.
Oral NR runs around $40 to $80 per month at therapeutic doses. NMN is in a similar range. IV NAD+ infusions in Philly typically cost $500 to $1,000 per session at higher doses, with shorter low-dose options available for $200 to $400.
Look for a clearly listed manufacturer, third-party testing certificates (NSF, USP, ConsumerLab), publicly available certificates of analysis, transparent dosing, and peer-reviewed research from the brand or its ingredients. Glossy ads do not pass that test.
Treat sponsored recommendations with healthy skepticism. Many wellness podcasters have meaningful financial relationships with the brands they endorse. Use those endorsements as a starting point and check the underlying clinical data before purchase.

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