"No fillers" on an NMN capsule means the label lists NMN and the capsule shell and nothing else: no flow agent, no bulking powder, no second active. RGENR8 Pure NMN Pro is 500mg of NMN in a vegan HPMC shell and nothing else, and on 14 October 2026 we read the product pages of 13 other UK brands to see how they compare.
What "no fillers" means for NMN capsules
Open a capsule and you find powder. In some products that powder is all NMN. In others it is NMN mixed with a second powder, such as rice flour, or with a small amount of a flow agent such as magnesium stearate or silicon dioxide. Those extra ingredients are called excipients. They are legal, they go on the label, and plenty of well-made supplements use them.
If you want to avoid them, the test is simple. Read the ingredient list. A capsule with no fillers lists NMN, plus the shell material, and that is it. If the page lists nothing at all, you cannot tell, and that is worth knowing too.
Pure NMN Pro is one ingredient in a vegan shell. See Pure NMN Pro
Why some capsules contain flow agents
Capsule-filling machines work best with powder that pours evenly. NMN powder can clump and cling to equipment, so some manufacturers add a flow agent to keep production steady. Others add a bulking powder so the capsule is full even when the active dose is small. Magnesium stearate, silicon dioxide and rice flour are the three you will see most often on supplement labels.
It is an ordinary manufacturing choice, and the label has to show it. What matters to a buyer is that you can see it on the label, and that it affects two practical things: whether the capsule is only NMN, and how much NMN fits in it. A capsule has a fixed volume, so every milligram of added powder is room that NMN is not using. For more on what else to check, see our NMN purity and certificate of analysis checklist.
Want the single-ingredient option? See Pure NMN Pro
What is in each 500mg NMN capsule sold in the UK (checked 14 October 2026)
We took the 500mg capsule products from the UK NMN Price Index and read each product page for its stated ingredients. Where a page says nothing, the table says so. We did not test any product. This is what each seller's page states, on the day we looked.
| Brand | Product | Capsule shell | Anything else listed |
|---|---|---|---|
| RGENR8 | Pure NMN Pro | Vegan HPMC | Nothing else. 500mg NMN per capsule, no fillers or binders |
| Naturecan | NMN supplement 500mg | HPMC (vegan) | No ingredient list in the page text. Page says no fillers |
| Voyager Life | NMN 500mg delayed release | HPMC delayed release | Hydroxypropyl methyl cellulose, listed with NMN |
| Supplements Wise | NMN 500mg delayed release | HPMC delayed release | Hydroxypropyl methyl cellulose, listed with NMN. Page says no rice flour or bulking agents |
| Simple Science | NMN 99%, 60 x 500mg | HPMC (vegan) | Purified water |
| Element 5 | NMN 500mg | Not stated on the product page | No ingredient list. Page says additives: none |
| Elixer | Pure NMN 500mg capsules | HPMC delayed release | No ingredient list. Page says no fillers beyond what holds the capsule together |
| Nutripact | NMN 500mg capsules | HPMC delayed release | Hydroxypropyl methyl cellulose, listed with NMN |
| Vivanmn | Pure NMN 500mg capsules | Not stated on the product page | Not stated on the product page |
| Charava | NMN 500 | Hypromellose | Nothing else listed |
| NMN Bio | NMN supplement capsules 500mg | Vegetable cellulose | Nothing else listed |
| DoNotAge | NMN 500mg | Vegetable cellulose | Cellulose |
| ProHealth Longevity | NMN Pro 500 | Vegetable capsule (material not named) | Rice flour |
Checked 14 October 2026 from each brand's own product page or retailer listing. "Listed with NMN" means the page names hydroxypropyl methyl cellulose in the ingredient line as well as the shell. Product pages change, so check the current label before you buy. The full check, with the wording we read on each page, is free to download and cite as a CSV: NMN capsule ingredients, UK, October 2026 (CC BY 4.0, please credit RGENR8). We left out capsules where the 500mg dose is spread over two capsules: Welzo's Ultra Purity NMN Pro 500 and Youth & Earth's NMN capsules are 250mg each, and both list an extra ingredient (vegetable magnesium stearate and rice flour respectively). We also left out KIKI Health, because its page does not state the dose per capsule.
Reading across the table, most brands list NMN and a plant-based shell only. One lists rice flour. A few do not publish an ingredient list on the product page at all, so "no fillers" is a claim you have to take on trust. Where a page says a product has no fillers, we have recorded that as the brand's statement.
RGENR8 prints the full list: 500mg NMN, vegan HPMC shell. See Pure NMN Pro
How to check a label for fillers
- Read "other ingredients". Anything after NMN and the shell is an excipient or an added active. Names to look for include magnesium stearate, silicon dioxide, microcrystalline cellulose, rice flour and calcium carbonate.
- Check the shell if you are vegan. HPMC (hypromellose), vegetable cellulose and pullulan are plant-based. Gelatin is not.
- Look for added actives. Resveratrol, TMG or quercetin in the same capsule change what is left for NMN. A "500mg complex" can mean 500mg across three capsules.
- Find the dose per capsule, not per serving. A 500mg serving of two capsules is 250mg each.
- Ask for the batch's analysis. A certificate of analysis should name the batch, the lab and the purity result. Our NMN purity and certificate of analysis checklist shows what a proper one contains.
The FSA's guidance on food supplements sets out what a supplement has to put on its label.
Ready to compare against a label with nothing else on it? See Pure NMN Pro
Price
RGENR8's quarterly subscription costs £27.99 for the first order with code WELCOME20: 90 capsules, 31p a day and £0.62 a gram. After that it is £34.99 every 3 months. A single bottle of 30 capsules is £24.95. On that first order, it is the lowest first-order price per gram of any 500mg NMN capsule pack under 1,000 capsules in the UK NMN Price Index, and the working is in our NMN price per gram guide. Our Best NMN supplement UK 2026: the main brands compared puts price next to purity and testing.
Common questions
Which NMN capsules have no fillers?
RGENR8 Pure NMN Pro is 500mg of NMN in a vegan HPMC shell and nothing else. Of the 13 other 500mg capsule products we read on 14 October 2026, most list only NMN and a capsule shell, one lists rice flour and several do not publish a full ingredient list on the product page. Check the label of whatever you buy.
Why do some NMN capsules contain magnesium stearate or rice flour?
Capsule-filling machines need powder that flows evenly. Some makers add a flow agent such as magnesium stearate or silicon dioxide, or a bulking powder such as rice flour, to help with that. It is a manufacturing choice and the ingredient is listed on the label when it is used.
Does a filler change how much NMN is in each capsule?
It can. A capsule holds a fixed volume, so any added powder takes up room that NMN could use. That is why some products that add a bulking powder split a 500mg serving across two capsules. Check the dose per capsule and the serving size, not just the headline figure.
Are NMN capsules with no fillers vegan?
Only if the shell is plant-based. HPMC (hypromellose) and vegetable cellulose shells are vegan, while gelatin shells are not. RGENR8 Pure NMN Pro uses a vegan HPMC shell.
Is NMN legal to buy in the UK?
NMN has no GB novel food authorisation yet. The application, RP-2116, is at risk assessment with the Food Standards Agency, and you can follow it on the FSA register.
If you are pregnant, breastfeeding, taking medication or managing a health condition, check with your GP or pharmacist before taking any supplement.
Choose a capsule that tells you what is in it. Shop Pure NMN Pro.
