NMN and NR supplements are broken down into nicotinic acid by gut microbes, negating premium pricing and functional benefits.
Original: New Study Says I Was Wrong About NMN and NR?
TL;DR
Current evidence indicates that NMN and NR supplements are metabolized by gut bacteria into nicotinic acid, which the body uses to make NAD+, but this does not lead to measurable improvements in health or performance.
Quick Answer
Yes, the creator admits he was wrong—not because NMN or NR don’t raise NAD levels, but because both supplements are broken down by gut bacteria into nicotinic acid (a cheap form of vitamin B3) before being converted to NAD via the Preiss-Handler pathway. Multiple human studies show that despite increasing blood NAD levels, neither NMN nor NR improves muscle function, metabolism, or symptoms in long-COVID patients. The entire debate over which supplement is better is irrelevant because both end up using the same metabolic route and fail to deliver measurable health benefits.
Claims (5)
1. When you take NR or NMN supplements, your gut bacteria turn them into a form of vitamin B3, which your body then uses to make an important molecule called NAD+ that helps keep your cells healthy.
2. Even though taking NR or NMN boosts a molecule called NAD+ in the blood, we don’t actually have solid proof it makes people stronger, healthier, sharper, or more energetic.
3. If your body shows higher levels of a molecule called NAAD after taking NR or NMN supplements, it might mean your body is using a special pathway that only works with niacin (nicotinic acid) to make energy molecules.
4. If you take antibiotics that wipe out your gut bacteria, your body can't turn a supplement called nicotinamide riboside into a form that helps make an important molecule called NAD+, so it doesn't work anymore.
5. After being given through an IV, NMN and NR end up in your gut through bile, where your gut bacteria turn them into a form of vitamin B3 that your body can use to make an important energy molecule called NAD+.
Key Takeaways
- •Problem: People take expensive NMN and NR supplements to boost NAD and slow aging, but they don’t actually improve real-world health like strength, energy, or brain function.
- •Core methods: Taking NMN or NR supplements orally or intravenously, relying on gut bacteria, and comparing results to placebo in clinical trials.
- •How methods work: Gut bacteria break down NMN and NR into nicotinic acid (a basic form of vitamin B3), which your body then uses to make NAD through the Preiss-Handler pathway—so you’re just paying for a cheap vitamin in an expensive form.
- •Expected outcomes: Blood NAD levels go up, but there’s no improvement in muscle strength, walking speed, metabolism, or long-COVID symptoms like fatigue and brain fog.
- •Implementation timeframe: Studies lasted 14 days to 20 weeks, and no benefits were seen even after long-term use.
Overview
A central theory in aging research posits that declining NAD+ levels contribute to age-related dysfunction, prompting widespread use of NAD precursors like NMN and NR. However, emerging evidence challenges both the mechanism and efficacy of these supplements. This analysis reviews human clinical data showing that NMN and NR are metabolized not through direct cellular uptake but via gut bacterial conversion to nicotinic acid, followed by systemic recycling into NAD. Furthermore, despite robust increases in blood NAD, no functional benefits have been demonstrated across muscle, metabolic, or cognitive domains in older adults or clinically stressed populations such as long-COVID patients.
Key Terms
How to Apply
- 1.Step 1: Take 1,200 mg per day of either NR or NMN orally for at least two weeks, as used in human clinical trials.
- 2.Step 2: Monitor blood NAD levels through clinical testing to confirm elevation, understanding that increases do not guarantee functional improvements.
- 3.Step 3: Evaluate personal outcomes in muscle strength (e.g., grip test), walking speed, metabolic markers (fasting glucose, lipids), and cognitive or fatigue symptoms over 14–20 weeks, comparing against baseline or placebo expectations.
- 4.Step 4: Recognize that any NAD increase is likely due to gut bacterial conversion of NR/NMN into nicotinic acid, a process confirmed even with intravenous dosing via bile recycling.
Blood NAD levels will increase significantly, but no measurable improvements in physical performance, metabolic health, or neurological symptoms are expected based on current clinical evidence.
Studies from Description (11)
Unprocessed Studies (1)
Claims (5)
1. When you take NR or NMN supplements, your gut bacteria turn them into a form of vitamin B3, which your body then uses to make an important molecule called NAD+ that helps keep your cells healthy.
2. Even though taking NR or NMN boosts a molecule called NAD+ in the blood, we don’t actually have solid proof it makes people stronger, healthier, sharper, or more energetic.
3. If your body shows higher levels of a molecule called NAAD after taking NR or NMN supplements, it might mean your body is using a special pathway that only works with niacin (nicotinic acid) to make energy molecules.
4. If you take antibiotics that wipe out your gut bacteria, your body can't turn a supplement called nicotinamide riboside into a form that helps make an important molecule called NAD+, so it doesn't work anymore.
5. After being given through an IV, NMN and NR end up in your gut through bile, where your gut bacteria turn them into a form of vitamin B3 that your body can use to make an important energy molecule called NAD+.
Claims (5)
1. When you take NR or NMN supplements, your gut bacteria turn them into a form of vitamin B3, which your body then uses to make an important molecule called NAD+ that helps keep your cells healthy.
2. Even though taking NR or NMN boosts a molecule called NAD+ in the blood, we don’t actually have solid proof it makes people stronger, healthier, sharper, or more energetic.
3. If your body shows higher levels of a molecule called NAAD after taking NR or NMN supplements, it might mean your body is using a special pathway that only works with niacin (nicotinic acid) to make energy molecules.
4. If you take antibiotics that wipe out your gut bacteria, your body can't turn a supplement called nicotinamide riboside into a form that helps make an important molecule called NAD+, so it doesn't work anymore.
5. After being given through an IV, NMN and NR end up in your gut through bile, where your gut bacteria turn them into a form of vitamin B3 that your body can use to make an important energy molecule called NAD+.
Related Content
Claims (5)
When you take NR or NMN supplements, your gut bacteria turn them into a form of vitamin B3, which your body then uses to make an important molecule called NAD+ that helps keep your cells healthy.
If your body shows higher levels of a molecule called NAAD after taking NR or NMN supplements, it might mean your body is using a special pathway that only works with niacin (nicotinic acid) to make energy molecules.
If you take antibiotics that wipe out your gut bacteria, your body can't turn a supplement called nicotinamide riboside into a form that helps make an important molecule called NAD+, so it doesn't work anymore.
After being given through an IV, NMN and NR end up in your gut through bile, where your gut bacteria turn them into a form of vitamin B3 that your body can use to make an important energy molecule called NAD+.
Even though taking NR or NMN boosts a molecule called NAD+ in the blood, we don’t actually have solid proof it makes people stronger, healthier, sharper, or more energetic.
Studies (9)
Discoveries of nicotinamide riboside as a nutrient and conserved NRK genes establish a Preiss-Handler independent route to NAD+ in fungi and humans.
DOI: 10.1016/S0092-8674(04)00416-7
Nicotinamide riboside promotes Sir2 silencing and extends lifespan via Nrk and Urh1/Pnp1/Meu1 pathways to NAD+.
DOI: 10.1016/j.cell.2007.03.024
Long-Term Administration of Nicotinamide Mononucleotide Mitigates Age-Associated Physiological Decline in Mice.
DOI: 10.1016/j.cmet.2016.09.013
The differential impact of three different NAD+ boosters on circulatory NAD and microbial metabolism in humans
DOI: 10.1038/s42255-025-01421-8
NAD precursors cycle between host tissues and the gut microbiome
DOI: 10.1016/j.cmet.2022.11.004