When people start researching NAD+ supplementation, they almost always hit the same fork in the road: NR or NMN? Both are NAD+ precursors. Both are backed by human clinical trials. Both are safe, well-tolerated, and available from NADBio as pure, SGS-tested supplements. So which one should you take?
The honest answer is that for most people, either will raise NAD+ levels meaningfully. But they do work through slightly different mechanisms, have different evidence profiles, and may suit different priorities. This guide gives you the complete picture — so you can make the right choice for your specific situation.
Head-to-Head Comparison
| NR — Nicotinamide Riboside | NMN — Nicotinamide Mononucleotide | |
|---|---|---|
| Steps to NAD+ | 2 steps (NR → NMN → NAD+) | 1 step (NMN → NAD+) Closer |
| Absorption route | Passive absorption across gut wall | Dedicated NMN transporter (Slc12a8) |
| Human clinical trials | More published trials Larger evidence base | Growing body of human trials |
| NAD+ increase | 40–90% rise in 4–8 weeks | 40–90% rise in 4–8 weeks |
| NADBio form | Liposomal capsules (2–3× absorption) + powder | Capsules + pure powder |
| Best evidence for | Energy, muscle metabolism, general NAD+ restoration | Aerobic capacity, insulin sensitivity, endurance |
| UK FSA approved? | Yes | No at application in progress |
| Price (NADBio) | From £33 / 60 servings | On backorder |
What is Nicotinamide Riboside (NR)?
Nicotinamide Riboside is a form of vitamin B3 first identified in milk as a natural NAD+ precursor. It was the first of the two to be extensively studied in human clinical trials, and today has the largest body of published human evidence of any NAD+ precursor.
NR is absorbed passively across the gut wall and enters cells relatively easily. Once inside, it is converted to NMN and then to NAD+ via the Preiss–Handler and salvage biosynthesis pathways.
Converted by NMRK1/2 enzymes. NADBio's Liposomal NR protects the molecule during digestion for 2–3× better delivery.
Absorbed via the Slc12a8 transporter directly into intestinal cells. Converted in one step by NMNAT enzymes.
The key advantage of NR is its track record. It has been studied in a wider range of populations and conditions than NMN, giving us a more complete picture of its safety profile, effective dosing range, and which groups benefit most. NADBio's Liposomal NR addresses the primary limitation of standard NR capsules — absorption — by encapsulating the active ingredient in phospholipid vesicles for significantly improved cellular delivery.
What is Nicotinamide Mononucleotide (NMN)?
Nicotinamide Mononucleotide is positioned one step further along the NAD+ biosynthesis pathway than NR — it is the direct precursor to NAD+, requiring only a single enzymatic conversion. It is also found naturally in small amounts in edamame, broccoli, avocado, and tomatoes, though dietary sources provide a tiny fraction of therapeutic doses.
The discovery of a dedicated NMN transporter protein (Slc12a8) in the small intestine's gut lining suggested that the body has evolved specific machinery for absorbing NMN directly — an indication that it plays a meaningful natural role in NAD+ biosynthesis. This transporter allows NMN to enter intestinal cells intact rather than being broken down into NR first.
At higher doses, NMN supplementation can gradually consume methyl groups as part of its metabolism — potentially reducing methylation capacity over time. Taking TMG (trimethylglycine) alongside NMN replenishes these methyl groups and is recommended by many practitioners, particularly at doses above 500mg/day. This consideration is less significant with NR at standard doses.
"In my view, NADBio are the most reputable source for NAD+ supplements in the UK. They arrive fast, respond quickly, and are completely open about their testing. I've been on NR for 14 months and my energy is consistently better."
"I'm a competitive triathlete and switched to NMN 6 months ago. My recovery times have improved noticeably and my VO2 max test came back better than it was 3 years ago. The powder form makes dosing very flexible."
Which Is Right For You?
Answer three quick questions and we'll give you a personalised recommendation based on your priorities.
Can You Take Both? The Combined Stack
Yes — and many people do. NR and NMN work through the same pathway, so taking both is not harmful or wasteful. However, it is also not necessary for most people. The main arguments for combining them are: maximising precursor availability via two slightly different absorption mechanisms, and covering any variability in individual response to each form.
A more common and arguably more impactful combination is pairing either NR or NMN with Resveratrol — which activates the SIRT1 sirtuin that NAD+ fuels — and TMG to maintain methyl balance. This is the full longevity stack and the approach used by many people following structured healthspan protocols.
Independent testing has found that a significant number of NR and NMN products on the UK market contain far less active ingredient than their labels claim. Always verify a certificate of analysis from a recognised independent laboratory before purchasing. NADBio publishes SGS test results for every product on its product pages.
Both options. One trusted source.
NADBio's NR and NMN are SGS third-party tested, held in UK stock, and dispatched same day. Whichever you choose, you know exactly what you're getting.
