The evidence

The science behind nitric oxide

One molecule touches nearly every system in the body. Here is the research — grouped by what it affects. Tap any area to read the studies.

Awarded the 1998 Nobel Prize in Medicine · 19 areas · 63+ references

Nitric oxide is the body's master signalling molecule for blood flow and vascular health. As it declines with age, system after system feels it. Below, each benefit links to peer-reviewed research — open studies, meta-analyses and reviews you can read yourself.

Cardiovascular

01 Heart healthNitric oxide keeps your arteries relaxed and flexible. Higher nitrate intake is linked to lower cardiovascular risk.
02 Lowering blood pressureDietary nitrate and NO precursors produce measurable, repeatable drops in blood pressure — in healthy and hypertensive adults alike.
03 Cholesterol & artery healthIn people with high cholesterol, dietary nitrate improves the function of the artery lining and calms the inflammation that builds plaque.

Brain & metabolic

04 Brain health & dementiaNitric oxide raises blood flow to the brain, and loss of NO is mechanistically tied to cognitive decline and Alzheimer's changes.
05 Reducing inflammationRestoring NO through the nitrate pathway lowers vascular inflammatory markers and helps inflammation resolve.
06 Energy & mitochondriaNO helps build new mitochondria and makes them more oxygen-efficient — so your cells produce more energy from less oxygen.
07 Type 2 diabetes & metabolismMixed evidenceNO metabolism is impaired in diabetes; dietary nitrate reliably raises NO markers, though effects on blood sugar in established diabetes are mixed.

Performance & vitality

08 Exercise performanceBeetroot-derived nitrate lowers the oxygen cost of exercise and can improve endurance and high-intensity tolerance.
09 Erectile dysfunctionErections depend on the NO/cGMP pathway. NO precursors L-citrulline and L-arginine help mild-to-moderate erectile dysfunction.
10 Hormonal & reproductive signallingComplex scienceNO is a key messenger in the brain's control of reproductive hormones. Its role in steroid production is nuanced — not a simple 'testosterone booster'.
11 ImmunityImmune cells use nitric oxide as a frontline weapon against viruses, bacteria, fungi and parasites.

Specialised areas

12 Herpes & antiviralEmerging · lab researchIn laboratory studies, nitric oxide can suppress herpes simplex virus replication as part of the body's antiviral response.
13 Bone healthMixed evidenceNO helps regulate bone remodelling — supporting bone-building cells and restraining bone loss — though human trial results are mixed.
14 Raynaud's phenomenonTopical NO donors increase blood flow to the fingers and reduce the frequency and severity of Raynaud's attacks.
15 MenopauseEmergingNO availability falls through menopause as oestrogen drops. The NO precursor L-citrulline shows early benefit for blood-vessel function and blood pressure.
16 Andropause & male ageingEmergingTestosterone supports NO production in blood vessels; low testosterone in ageing men is linked to reduced NO and endothelial dysfunction.
17 Wound healingEmerging · mostly preclinicalNO is essential for healing and is deficient in diabetic wounds; NO precursors and donors improve healing in animal and early clinical studies.
18 Kidney healthMechanisticChronic kidney disease features nitric oxide deficiency, which drives high blood pressure and vessel dysfunction; the arginine–NO pathway helps regulate kidney blood flow.
19 Skin & ageingEmergingNO regulates skin blood flow, collagen-related processes and UV responses — an emerging area for skin health and photo-ageing.