What's the Best NAD Supplement to Take? A 2025 Guide

January 8, 2026 •

4 min read

Our bodies' natural production of nicotinamide adenine dinucleotide (NAD+) declines significantly with age, decreasing by as much as 65% between the ages of 30 and 70. This drop is linked to various cellular dysfunctions, driving many to seek supplements to replenish their levels. Deciding on the right option, however, requires understanding the different forms available and how they work.

Quick Summary

NAD supplements come in precursor forms like NMN and NR, which offer better bioavailability than direct NAD+ oral supplements. The optimal choice depends on factors like your health goals, budget, and delivery method, such as capsules or liposomal. Always prioritize quality, third-party testing, and consulting a healthcare professional before starting supplementation.

Key Points

NMN vs. NR: NMN is a more direct precursor to NAD+, while NR converts to NMN first, yet both are effective at raising NAD+ levels.
Oral Supplements Are Precursors: Taking precursors like NMN or NR is more effective for boosting NAD+ than taking NAD+ directly, which has poor oral bioavailability.
Choose Based on Research: NR has a more established history of human clinical trials, with Niagen® being a well-researched, proprietary form.
Delivery Matters: Bioavailability varies with delivery. Liposomal and sublingual methods may offer better absorption than standard capsules, though capsules are the most studied.
Look for Third-Party Testing: Ensure your chosen supplement has been independently tested for purity and potency by organizations like NSF or USP.
Pairing for Synergy: Combining NAD precursors with other supplements like Resveratrol or CoQ10 can amplify their cellular benefits and support methylation.

Understanding NAD and Its Role in Cellular Health

Nicotinamide adenine dinucleotide (NAD) is a critical coenzyme found in every cell of the human body. It plays a foundational role in hundreds of metabolic processes, essentially acting as a shuttle for electrons during energy production within the mitochondria, the cell's powerhouse. Its functions are broad and essential for life, including DNA repair, regulation of circadian rhythms, and activation of signaling proteins known as sirtuins, which are key to cellular health and longevity. The natural decline of NAD+ with age is a primary driver behind age-related cellular decline. Supplementing with NAD+ precursors is a popular method to potentially restore these levels.

The Primary NAD Precursors: NMN vs. NR

Direct oral NAD+ supplements are largely ineffective because the molecule is too large and unstable to survive digestion and enter cells efficiently. Therefore, most supplements provide precursors, or building blocks, that the body can convert into NAD+.

Nicotinamide Mononucleotide (NMN)

Nicotinamide mononucleotide (NMN) is a direct precursor to NAD+, meaning the body can convert it into NAD+ in just a single step. Recent research identified a specific transporter protein, Slc12a8, which helps facilitate NMN's direct entry into cells, particularly those in the small intestine, potentially making it a very efficient way to raise NAD+ levels. NMN has been shown in animal studies to improve metabolic and physical function. However, the U.S. FDA has raised regulatory issues regarding NMN's status as a dietary supplement. This regulatory uncertainty has led to market fluctuations and restrictions on major retail platforms.

Nicotinamide Riboside (NR)

Nicotinamide riboside (NR) is another widely-researched precursor, a form of vitamin B3. It first converts into NMN inside the cell before becoming NAD+. While NR has an extra conversion step compared to NMN, it is backed by a substantial body of human clinical research affirming its safety and effectiveness in boosting NAD+ levels. Brands like Tru Niagen have invested heavily in research, leading to a strong record of safety and proven efficacy. NR is often a preferred choice for those seeking a well-studied precursor with fewer regulatory concerns.

NADH

NADH, or nicotinamide adenine dinucleotide + hydrogen, is the reduced, electron-carrying form of NAD+. While it is a key player in energy production, NADH supplements face challenges related to oral absorption and stability compared to precursors like NMN and NR. For most consumers, focusing on precursors that efficiently raise NAD+ levels is a more practical approach.

Comparing NAD Precursors for Optimal Choice

Choosing the best supplement depends on your specific goals and preferences. The table below summarizes the key differences between the most common NAD precursors.


Feature	NMN (Nicotinamide Mononucleotide)	NR (Nicotinamide Riboside)	NADH
Conversion Path	Converts directly to NAD+ in one step.	Converts to NMN, then to NAD+.	Reduced form of NAD+, less direct for supplementation.
Bioavailability	High absorption due to specific cell transporters. May require different delivery for max uptake.	High bioavailability and supported by significant clinical data.	Lower oral bioavailability; less efficient for raising NAD+.
Scientific Support	Strong animal research, growing human trials, but more recent.	Extensive human clinical trial data, especially for proprietary forms like Niagen®.	Limited evidence for effectiveness as an oral supplement.
Regulatory Status	US FDA has ruled it cannot be marketed as a dietary supplement due to drug investigation.	More established and accepted dietary supplement status.	Generally accepted, but less commonly used.
Cost	Varies widely; often more expensive due to sourcing and regulation.	Varies, with proprietary versions often more affordable than high-end NMN.	Varies; typically less of a focus for raising NAD+ levels.

Factors to Consider When Selecting Your Supplement

1. Delivery Method

Oral Capsules/Tablets: The most common and studied format. They are convenient and reliable for consistent use.
Liposomal: Encapsulates the precursor in lipid bubbles to protect it from digestion and potentially increase absorption. Often more expensive.
Sublingual Powders/Tablets: Held under the tongue for faster absorption directly into the bloodstream, bypassing the digestive system.
Nasal Sprays/IV Infusions: Offer rapid, high bioavailability but are typically more expensive and require professional administration for infusions.

2. Third-Party Testing and Quality

Since supplements are not strictly regulated, third-party testing is crucial to verify potency and purity. Look for certifications from organizations like NSF International or USP. Reputable brands provide this information transparently.

3. Combination Formulations

Some supplements combine NAD+ precursors with complementary ingredients like Resveratrol, CoQ10, or Betaine (TMG). These additions can activate sirtuins or support methylation, which can be depleted during NAD+ production. Consider these formulations if you want to streamline your supplement regimen.

Conclusion: Finding the Right Fit

There is no single "best" NAD supplement for everyone. The best option for you depends on your budget, health goals, and preference for a particular precursor or delivery method. While NMN offers a direct conversion pathway and advanced delivery options, NR has a longer history of safety and human clinical evidence supporting its effectiveness. For those prioritizing a well-researched, established track record, NR from a reputable, third-party-tested brand like Tru Niagen is an excellent choice. If you are willing to navigate regulatory ambiguity for a potentially more direct pathway, a high-quality NMN product might be preferable. Regardless of your choice, consult with a healthcare professional to ensure it aligns with your overall health needs and remember that supplements work best alongside a healthy lifestyle.

For a deeper dive into the biochemistry of NMN and NAD+, the National Institutes of Health offers comprehensive resources.

Frequently Asked Questions

The main difference lies in the conversion path to NAD+. NMN is converted in a single step, while NR must first be converted into NMN before becoming NAD+. Both are effective precursors for boosting cellular NAD+ levels.

In 2022, the FDA ruled that NMN could not be marketed as a dietary supplement because it was first investigated as a drug. This resulted in major retailers restricting sales, but the regulatory status remains contested and a subject of ongoing legal challenges.

Short-term human clinical trials suggest that NAD precursors like NMN and NR are generally safe and well-tolerated. However, long-term safety is not yet fully established, and experts advise cautious optimism while more research is conducted.

While NAD precursors are found in small amounts in foods like broccoli, avocado, and dairy, the concentration is very low. Supplementation provides a much higher, more targeted concentration than can realistically be obtained from diet alone.

NAD precursors can be taken alone, but some formulations combine them with other nutrients like Resveratrol, CoQ10, or B vitamins for synergistic effects. These additions can support related pathways like mitochondrial health or cellular repair.

Liposomal delivery encases the supplement in lipid bubbles, protecting it from digestive enzymes and potentially increasing absorption and bioavailability. It is often a more expensive option but may be beneficial, especially for older adults with potentially reduced digestive efficiency.

Determining the appropriate intake of NAD supplements can vary based on individual needs and the specific product. Research and product guidelines often provide general information. It is always recommended to consult with a healthcare professional to receive personalized advice tailored to your health status and goals before beginning any supplement regimen.