Longevity Box vs Welzo: UK Longevity Brands Compared

Last updated: July 2026 · Written by the Welzo Longevity Team

If you have been researching UK longevity supplements, you have almost certainly come across two names: Longevity Box and Welzo. This in-depth Longevity Box review compares both brands side by side — product range, purity and testing, pricing, guarantees, real customer feedback and the actual science behind NAD⁺ boosters like NMN — so you can decide which is the better fit for your health goals and budget. Before you buy from either, it helps to understand the category itself. Our pillar guide to longevity supplements maps out what each compound does, and our guide to NMN benefits, side effects and dosage covers the most-studied one in detail. If you already know what you want, browse the full range of anti-ageing and longevity supplements and NMN supplements, or go straight to the Welzo Ultra Purity NMN Pro 1000. Both companies sell many of the same core longevity compounds (NMN, resveratrol, TMG, spermidine and more), so the differences come down to formulation strategy, dosing, transparency and value.

Longevity Box review at a glance

Here is the short version before we get into the detail.

Above: a 3D model of NAD⁺, the coenzyme that NMN, NMNH and NR are designed to replenish. Image: Wikimedia Commons (public domain).

Who is Longevity Box?

Longevity Box (longevitybox.co.uk) is a UK-based supplement company that began as a family-run business in Warwickshire, England, with the stated aim of making premium-grade longevity supplements more accessible. The brand has built its identity around three things: no fillers or binders, independent lab testing, and an unusually long 700-day purity guarantee alongside a customer money-back guarantee.

It is one of the more visible longevity retailers in the UK and has thousands of customer reviews across public platforms, which makes it a useful reference point for anyone comparing where to buy NMN in the UK.

What does Longevity Box sell?

Longevity Box offers one of the broader catalogues in the UK longevity space. Alongside standard NMN powder and capsules, its range includes:

• NMNH — a reduced (“dihydro”) form of NMN marketed as its flagship, higher-potency NAD⁺ booster
• Nicotinamide Riboside (NR) — an alternative NAD⁺ precursor (see our Tru Niagen vs NMN comparison)
• Trans-resveratrol and trans-pterostilbene (see resveratrol vs pterostilbene)
• TMG (trimethylglycine) — a methyl donor often paired with NMN
• Spermidine, Ca-AKG, GlyNAC, apigenin, sulforaphane, magnesium glycinate and a MitoSurge Urolithin A product
• Multi-ingredient bundles such as an “Ultimate Anti-Ageing” stack

If you want to understand what each of these compounds does before committing, Welzo has dedicated guides on spermidine, Ca-AKG, GlyNAC and Urolithin A.

Longevity Box quality and testing claims

Longevity Box states that its products are independently (third-party) lab tested, over 99% pure for its core NAD⁺ ingredients, and free from additives, binders and fillers. Independent lab testing is exactly what you should look for in this category — our guides to third-party tested supplements and reading a certificate of analysis (CoA) explain why. As with any brand, the practical advice is to check that a current CoA is available for the specific batch you are buying.

NMNH: Longevity Box’s flagship — with an honest caveat

Longevity Box heavily promotes NMNH, the reduced form of NMN, with marketing claims that it is several times more potent than ordinary NMN and raises NAD⁺ more effectively. It is important to be clear and evidence-based here: NMNH is a real and interesting compound, and early preclinical (cell and animal) research does suggest it can raise NAD⁺ efficiently. However, the large, published, placebo-controlled human trials that exist for NAD⁺ boosters have overwhelmingly studied conventional NMN and NR, not NMNH. In other words, the “next-generation” potency claims are promising but not yet backed by the same weight of human evidence as standard NMN. We explain this distinction further in the NMNH vs NMN section below and in our NAD⁺ supplement guide.

What customers actually say about Longevity Box

A fair review has to include the mixed picture. Longevity Box has a large volume of public reviews on platforms such as Trustpilot, and the feedback trends in both directions.

Positive feedback

• Many long-term customers report timely delivery, helpful and informative email support, and products that arrive well packaged.
• Repeat buyers frequently mention subjective improvements in energy and focus, and appreciate the filler-free, flat-pack format.
• Reviewers value the breadth of novel compounds (NMN, NMNH, Ca-AKG, GlyNAC, spermidine) available from a single UK retailer.

Common complaints

• Some reviewers report inconsistent results or scepticism about whether they felt any effect — a normal outcome for supplements, since benefits are often subtle and long-term.
• A minority raise concerns about batch consistency (for example, an unexpected colour in one capsule) and question quality control.
• Isolated fulfilment issues have been reported (in one case a customer initially received only a dosing spoon, which the company then remedied).
• Pricing on some items is not the lowest available — several reviewers note you can find cheaper equivalents elsewhere.

The overall takeaway: Longevity Box is a real, responsive UK company with a loyal customer base, but — as with every supplement brand — individual results and experiences vary. If price is your main concern, it is worth comparing against our roundup of the cheapest NMN in the UK. And if you are wondering whether the whole category is worthwhile, our honest explainer “Is NMN a scam?” is worth a read.

Who is Welzo?

Welzo is a UK-based health platform that dispatches from the UK and offers a focused, transparency-first longevity range under its Welzo Ultra Purity line. Rather than competing on catalogue breadth, Welzo’s approach centres on clean, single-ingredient formulas, clinically relevant doses, and clear labelling with no proprietary blends.

The Welzo Ultra Purity range

The Ultra Purity line covers the core longevity compounds most people actually build a routine around, and is designed so you can combine them yourself or buy ready-made stacks:

• NMN Pro 1000 — 1,000 mg NMN per serving
• NMN & TMG stack — NMN plus a methyl donor
• NMN & Resveratrol stack
• Sinclair-style stack (NMN + Trans-Resveratrol + TMG)
• Longevity & Cellular Support bundle (NMN + PQQ + Trans-Resveratrol)

NMN Pro 1000

Welzo’s flagship is NMN Pro 1000: a high-strength, high-purity beta-NMN capsule delivering 1,000 mg per serving, formulated for people who want a meaningful dose in a single product rather than stacking multiple low-strength capsules. It is manufactured to UK/EU quality standards, transparently labelled, and dispatched from the UK with free shipping over £50 — which avoids the import charges and customs delays that can come with US longevity brands. Notably, 1,000 mg sits at the higher end of the doses used in the human trials discussed below.

Longevity Box vs Welzo: head-to-head comparison

The table below summarises how the two brands compare on the factors that matter most. Prices and specifications change frequently, so always confirm current details on each product page before buying.

Product range and formulations

Longevity Box wins on sheer breadth: if you want to experiment with newer compounds like NMNH, Ca-AKG or GlyNAC from one retailer, it has more options. Welzo wins on simplicity and dose clarity: single-ingredient products at meaningful strengths make it easy to know exactly what you are taking and to follow a clean daily routine. If you prefer to keep things lean, our minimal supplement stack guide is a useful companion.

Purity, testing and transparency

Both brands emphasise purity and testing. The differentiator for buyers is verifiability: look for a batch-specific certificate of analysis, clearly stated purity percentages, and no hidden “proprietary blends.” Our checklist on supplement fillers explains what to avoid on an ingredients label.

Dosage and value for money

Dose matters. As the trials below show, NMN’s measurable benefits in humans appeared at roughly 600–900 mg per day, so a 1,000 mg single-serving product reaches a research-relevant dose without stacking capsules. When comparing prices, calculate cost per gram of active ingredient per day rather than the sticker price — a “cheaper” low-dose product can cost more per effective dose. See our NMN dosage by age and cheap NMN UK guides for context.

Shipping, returns and guarantees

Longevity Box’s headline 700-day purity guarantee is genuinely generous for the category. Welzo counters with fast same-day UK dispatch and free UK shipping over £50. Both ship from within the UK, so neither should incur import fees for UK customers — a real advantage over many US brands.

The science: do these supplements really work?

Because this is a health topic, it is worth separating marketing from evidence. Here is what the research does and does not show.

What NAD⁺ does and why it declines

NMN, NMNH and NR are all precursors to NAD⁺ (nicotinamide adenine dinucleotide), a coenzyme essential for cellular energy production, DNA repair and the activity of “longevity” enzymes called sirtuins.^[5] NMN itself is a small nucleotide (molecular formula C₁₁H₁₅N₂O₈P; molecular weight ~334 g/mol) that the body converts into NAD⁺.^[8] NAD⁺ levels decline with age, and this decline is linked to several of the recognised hallmarks of ageing.^[4] The theory behind NAD⁺ boosters is simple: restore NAD⁺ toward more youthful levels and you may support cellular function. For a full primer, see our longevity supplements guide.

Above: the chemical structure of NMN (nicotinamide mononucleotide). Image: Wikimedia Commons (public domain).

What the human trials actually show

The most-cited human evidence for NMN comes from a randomised, double-blind, placebo-controlled, dose-dependent trial by Yi and colleagues, published in GeroScience in 2023. In healthy middle-aged adults, 60 days of NMN significantly increased blood NAD⁺ levels, and the 600 mg and 900 mg groups showed improved six-minute walking distance and self-reported wellbeing, while the 300 mg group did not show the same walking benefit.^[1] A separate randomised, double-blind study by Liao and colleagues, published in the Journal of the International Society of Sports Nutrition in 2021, found that NMN combined with exercise training improved aerobic capacity in amateur runners.^[2] And in a 2021 Science trial, Yoshino and colleagues reported that 10 weeks of NMN improved muscle insulin sensitivity in postmenopausal women with prediabetes.^[3]

Two honest caveats matter for a health topic like this. First, these are relatively small, short trials — promising, but not proof of long-term anti-ageing effects in humans; some researchers have even flagged design limitations and called for larger studies.^[6] Second, much of the excitement around NAD⁺ boosters still comes from animal research, which does not always translate to people. If you are new to the category, our guide on how long supplements take to work sets realistic expectations, and which longevity supplements don’t work keeps things grounded.

NMNH vs NMN: is “next-gen” proven?

Since NMNH is Longevity Box’s headline product, it deserves a clear-eyed look. NMNH is the reduced (dihydro) form of NMN. Laboratory and animal studies suggest it can raise NAD⁺ efficiently, which is the basis for the “more potent” marketing. However:

• The large, published, placebo-controlled human trials (including Yi 2023, Liao 2021 and Yoshino 2021) studied conventional NMN and NR — not NMNH.
• NMNH’s potency claims (for example, “several times more effective”) are largely extrapolated from preclinical data, not confirmed in large human trials.
• As a newer compound, its long-term safety profile in humans is less well characterised than NMN’s.

This does not mean NMNH is bad — it means the evidence bar is currently higher for conventional NMN. If you want the option with the most human data behind it today, a well-dosed beta-NMN is the more conservative, evidence-led choice. Curious how NMN compares to other popular NAD⁺ and cellular-energy compounds? See spermidine vs NMN and Urolithin A vs NMN.

Is NMN legal in the UK? Novel food status

This is an important, frequently misunderstood point. In Great Britain, NMN is treated as a “novel food” — a food or ingredient without a significant history of consumption in the UK or EU before May 1997 — which means it is subject to a pre-market authorisation process overseen by the Food Standards Agency (FSA).^[7] In practice, NMN is not banned and remains widely available for sale in the UK while its regulatory status is assessed, but reputable brands should market it strictly as a food supplement and avoid making medicinal claims (such as “treats” or “reverses” disease), which fall under separate MHRA medicines rules.^[9]

What this means for you as a buyer: choose UK-based retailers that dispatch from the UK, provide clear labelling and batch information, and do not over-promise. Both Longevity Box and Welzo operate as UK food-supplement retailers on this basis.

How to choose a UK longevity brand

Whether you go with Longevity Box, Welzo or another brand, use this checklist.

1. Third-party testing and a certificate of analysis

Insist on independent testing for identity, potency and contaminants, ideally with a batch-specific CoA available on request. This is the single most useful filter for separating credible brands from marketing-led ones.

2. Dose and purity that match the research

For NMN, human trials point to roughly 600–900 mg+ per day for measurable effects, so check the dose per serving, not just “contains NMN.” Prioritise stated purity (98–99%+) and vegan capsules without unnecessary fillers. If timing matters to you, see when to take NMN.

3. Do you need TMG with NMN?

Because NMN metabolism can consume methyl groups, some people pair it with TMG (a methyl donor). Whether you need to is nuanced — read do I need TMG with NMN? before deciding, and see buy TMG UK for options. Welzo also offers a ready-made NMN & TMG stack if you want both in one routine.

Longevity Box vs Welzo: which should you choose?

Choose Longevity Box if…

• You want the widest UK catalogue of novel compounds (NMNH, Ca-AKG, GlyNAC, spermidine, sulforaphane) from one retailer.
• You specifically want to try NMNH and are comfortable that its potency claims are still emerging.
• A long 700-day purity guarantee is a deciding factor for you.

Choose Welzo if…

• You want a clean, transparent, high-dose core stack built around a research-relevant 1,000 mg NMN serving.
• You prefer single-ingredient formulas and clear labelling with no proprietary blends.
• Fast same-day UK dispatch and simple, ready-made stacks matter to you.

Many people ultimately build a hybrid routine. If you want a done-for-you starting point, see our guides on how to start longevity supplements and building a sensible longevity stack.

Safety, side effects and who should avoid NMN

In the published human trials to date, NMN has generally been well tolerated at the doses studied, with no serious adverse effects reported.^[1] Mild, occasional effects some users report include digestive upset or flushing. Researchers do note that the long-term safety of NAD⁺-boosting supplements still requires further study, which is another reason to use sensible doses and involve a professional.^[10]

You should speak to a doctor or pharmacist before starting NMN or any longevity supplement if you are pregnant or breastfeeding, take prescription medication, have a diagnosed medical condition (including cancer, liver or kidney disease), or are under 18. Do not exceed the recommended dose, and remember supplements are not a replacement for a balanced diet, sleep, exercise and not smoking. For lifestyle levers with strong evidence, see our pieces on Blue Zones and Zone 2 training.

Frequently asked questions

Is Longevity Box a legitimate company?

Yes. Longevity Box is an established UK-based longevity supplement retailer from Warwickshire with a large volume of public customer reviews. Feedback is mixed but largely positive, with common praise for delivery, support and filler-free products, and some complaints around batch consistency and pricing on certain items.

Is Longevity Box or Welzo better value?

It depends on how you measure value. Compare cost per gram of active ingredient per day rather than sticker price. Welzo’s 1,000 mg NMN Pro 1000 reaches a research-relevant dose in one serving, while Longevity Box offers a broader catalogue. Always check current prices on each product page.

What is NMNH, and is it better than NMN?

NMNH is the reduced form of NMN and is Longevity Box’s flagship. Early lab and animal data suggest it raises NAD⁺ efficiently, but the large placebo-controlled human trials to date have studied conventional NMN and NR, not NMNH. Its “more potent” claims are promising but not yet confirmed in large human studies.

Is NMN legal to buy in the UK?

Yes, NMN is currently available to buy in the UK. It is classified as a “novel food” under FSA regulation, meaning its status is under assessment, but it is not banned and is widely sold as a food supplement. Choose UK-based retailers that avoid medicinal claims.

What NMN dose is backed by research?

In the Yi 2023 GeroScience trial, the 600 mg and 900 mg daily groups showed improved six-minute walking distance and wellbeing scores, while 300 mg did not show the same walking benefit. A 1,000 mg single-serving product reaches the upper research range without stacking capsules.

Do I need to take TMG with NMN?

Some people pair NMN with TMG, a methyl donor, because NMN metabolism can use methyl groups. Whether you personally need it is nuanced and depends on diet and health status. Consider a combined NMN & TMG stack for convenience, and consult a professional if unsure.

Does Longevity Box third-party test its products?

Longevity Box states its products are independently lab tested, over 99% pure for its core NAD⁺ ingredients, and free from fillers. As with any brand, ask for the batch-specific certificate of analysis for the exact product you intend to buy.

Are there side effects to NMN?

In published human trials, NMN has generally been well tolerated with no serious adverse effects reported at the doses studied. Some users report mild digestive upset or flushing. Consult a healthcare professional if you take medication or have a medical condition.

Can I take NMN with resveratrol?

Many longevity routines combine NMN with trans-resveratrol, and both brands sell combined options. Resveratrol’s human evidence is more mixed than its popularity suggests — read our honest explainer on whether resveratrol works before adding it.

Which is better for beginners, Longevity Box or Welzo?

Beginners often find Welzo’s focused, single-ingredient, clearly-dosed range easier to navigate, whereas Longevity Box’s broad catalogue suits enthusiasts who want to experiment with newer compounds. Either way, start simple, be consistent, and consult a professional if you have any health concerns.

References

1. Yi L, Maier AB, Tao R, et al. The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial. GeroScience. 2023;45(1):29–43. PubMed: 36482258.
2. Liao B, Zhao Y, Wang D, et al. Nicotinamide mononucleotide supplementation enhances aerobic capacity in amateur runners: a randomized, double-blind study. Journal of the International Society of Sports Nutrition. 2021;18(1):54. doi:10.1186/s12970-021-00442-4.
3. Yoshino M, Yoshino J, Kayser BD, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021;372(6547):1224–1229. doi:10.1126/science.abe9985.
4. Zhang M, Ying W, et al. The versatile multi-functional substance NMN: its unique characteristics, metabolic properties, pharmacodynamic effects, clinical trials, and diverse applications. Frontiers in Pharmacology. 2024;15:1436597. doi:10.3389/fphar.2024.1436597.
5. Shade C. The science behind NMN—a stable, reliable NAD⁺ activator and anti-aging molecule. Integrative Medicine (Encinitas). 2020;19(1):12–14. PMC7238909.
6. Comment on “Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women.” Science. 2021. doi:10.1126/science.abj1696.
7. Food Standards Agency. Novel foods authorisation guidance. food.gov.uk (accessed 2026).
8. National Center for Biotechnology Information. PubChem Compound Summary for CID 14180, Nicotinamide Mononucleotide. pubchem.ncbi.nlm.nih.gov (accessed 2026).
9. Medicines and Healthcare products Regulatory Agency (MHRA). gov.uk/MHRA (accessed 2026).
10. Wang X, et al. Nicotinamide mononucleotide: a potential effective natural compound against insulin resistance. Signal Transduction and Targeted Therapy. 2021;6:310. nature.com
    

Editorial note: Welzo sells longevity supplements referenced in this article. We aim to compare brands fairly using publicly available information; product details and prices change, so please verify current specifications on each brand’s official product pages.