NMN & NAD+ Precursors: What the 2026 Evidence Actually Says
Human trials, safety, dosing and the difference between NMN and NR.
Read Guide →Supplement Guides
Evidence-led guides to the most-discussed longevity supplements in the UK.
How to use this hub: We do not rank supplements as "best." Instead, each guide explains the mechanism, summarises human trials, notes side effects, and gives practical UK buying advice. Most pages include affiliate links where relevant; those links do not influence our editorial judgements. Read the full affiliate disclosure.
⚠️ Important: No supplement has been proven to extend human lifespan. Always consult a qualified healthcare professional before starting any supplement, especially if you are pregnant, nursing, taking medication or have a medical condition.
Ingredient Guides
NAD+ Precursors Compared: NR vs NMN for Longevity (UK)
Side-by-side comparison of bioavailability, trials, safety and buying advice.
Read Guide →Resveratrol vs Pterostilbene: Evidence, Dosing & UK Availability 2026
Bioavailability, human trials, dosing and how to choose between these stilbenes.
Read Guide →Spermidine: Food Sources, Supplements and Autophagy Evidence (UK)
Spermidine-rich foods, wheat-germ extract and the latest autophagy trials.
Read Guide →Spermidine & Autophagy: Oxford Vaccine Trial in Older Adults
Can a wheat-germ compound reboot cellular recycling and immune response?
Read Guide →Quercetin & Fisetin as Senolytics: What Human Trials Say (UK)
Clearing senescent cells: dasatinib + quercetin, fisetin and the safety caveats.
Read Guide →Omega-3 and Longevity: DHA, EPA, Inflammation and Heart Health (UK)
What REDUCE-IT, STRENGTH and meta-analyses say about fish oil and healthy ageing.
Read Guide →Vitamin D3 + K2 for Healthy Ageing in the UK: Evidence & Dosing
NHS guidance, bioavailability, K2's calcium-directing role and practical dosing.
Read Guide →Magnesium for Sleep and Muscle Health in Ageing: UK Evidence
Forms, dosing, deficiency risk and what trials say about cramps and insomnia.
Read Guide →Glycine and Collagen for Healthy Ageing: UK Evidence and Dosing
Collagen peptides for skin and joints, plus glycine's emerging role in ageing.
Read Guide →Metformin for Longevity: TAME Trial, Current Status and Risks (UK)
Why the world's most famous anti-ageing drug candidate is still unproven in healthy adults.
Read Guide →Rapamycin for Longevity: PEARL Trial 2025 Results Explained
One year of low-dose rapamycin in healthy adults — safety, healthspan signals and risks.
Read Guide →Quick Comparison: Evidence Strength
| Supplement / Topic | Human trial volume | Key claimed benefit | UK availability |
|---|---|---|---|
| NMN | Moderate, short-term | NAD+ elevation; metabolic markers | Food supplement |
| NR | Larger safety database | NAD+ elevation; some vascular markers | Food supplement |
| Resveratrol / Pterostilbene | Moderate (resveratrol); small (pterostilbene) | Vascular, metabolic, sirtuin signalling | Food supplement |
| Spermidine | Small but growing | Autophagy, immune response | Food / wheat-germ extract |
| Fisetin / Quercetin | Very small (fisetin); small (D+Q) | Senescent-cell clearance | Food supplement |
| Omega-3 (EPA/DHA) | Very large | Cardiovascular, triglycerides, anti-inflammatory | Food supplement / prescription |
| Vitamin D3 + K2 | Very large (D); small (K2) | Bone, muscle, immune | Food supplement |
| Magnesium | Moderate | Sleep, muscle relaxation, bone | Food supplement |
| Collagen / Glycine | Moderate (collagen); small (glycine) | Skin, joints, connective tissue | Food supplement |
UK Buying Checklist
- Check the active amount. A "1,000 mg fish oil" capsule may contain only 300 mg EPA/DHA; a "collagen" label may not state peptide type.
- Demand third-party testing. Look for certificates of analysis (COA), UKAS-accredited labs, or Informed Sport / NSF certification where relevant.
- Prefer UK-registered sellers. Returns, refunds and consumer rights are easier with a UK company.
- Avoid disease-treatment claims. In the UK, food supplements cannot legally claim to treat, cure or prevent disease.
- Start low and track response. More is rarely better, and the highest marketed doses often exceed trial doses.
- Check interactions. Vitamin K2 interacts with warfarin; omega-3 can affect bleeding risk; magnesium needs caution in kidney disease.
Foundational Health First
Before adding any supplement, the strongest evidence for healthy ageing still supports:
- Regular physical activity, including resistance training.
- Sufficient, consistent sleep.
- A diet rich in vegetables, legumes, whole grains, oily fish and fermented foods.
- Social connection and cognitive engagement.
- Not smoking and limiting alcohol.
Read our introduction to what longevity science actually means for context on lifespan vs healthspan.