The Science Behind Inner Heal NMN

Your body runs on a molecule most people have never heard of — and you start running out of it the older you get.

It’s called NAD+. Every cell in your body uses it to turn food into usable energy, repair damaged DNA, and keep inflammation in check. Here’s the problem: NAD+ levels fall steeply with age. In actual human tissue, researchers have measured a dramatic decline from youth into midlife — and the low-grade inflammation that builds up as we age burns through it even faster.

When NAD+ runs low, three things tend to follow: less energy, more pain sensitivity, and more inflammation. If that reads like the daily reality of fibromyalgia and midlife exhaustion — you’re not imagining it. Scientists are mapping the exact same biology.

NMN (nicotinamide mononucleotide) is the direct building block your cells use to rebuild NAD+. Inner Heal NMN is built on that one idea: give your cells the raw material to make NAD+ again.

We’re not asking you to take our word for it. Below are 45+ peer-reviewed studies — human clinical trials, animal experiments that can’t be explained by placebo, and the mechanisms that connect them. Click any title to read the original research for yourself.

1. NMN in humans — the clinical trials

Does swallowing NMN actually raise NAD+ in real people — and do they feel a difference? These randomized, placebo-controlled trials say yes, and they map the safety profile.

1. The efficacy and safety of β-NMN supplementation in healthy middle-aged adults: a dose-dependent RCT (GeroScience, 2023) Human80 adults; NMN raised blood NAD+ at every dose and let people walk noticeably farther in a 6-minute walking test.
2. Chronic NMN supplementation elevates blood NAD+ and alters muscle function in healthy older men (npj Aging, 2022) Human250 mg/day more than doubled NAD+ in the blood, with gains in walking speed and grip strength.
3. NMN increases muscle insulin sensitivity in prediabetic women (Science, 2021) HumanIn postmenopausal women, 10 weeks of NMN made muscle respond about 25% better to insulin — a core marker of metabolic health.
4. NMN supplementation enhances aerobic capacity in amateur runners: a double-blind RCT (J Int Soc Sports Nutrition, 2021) HumanRunners on NMN improved how well their muscles used oxygen — meaning more endurance, less breathlessness.
5. Oral NMN is safe and efficiently increases blood NAD+ in healthy subjects (Frontiers in Nutrition, 2022) Human12 weeks of 250 mg/day safely raised NAD+ with no harmful effects on bloodwork or how people felt.
6. Effect of oral NMN on clinical parameters and nicotinamide metabolite levels in healthy men (Endocrine Journal, 2020) HumanThe first-ever human study: a single dose up to 500 mg was safely processed — no problems with heart rate, blood pressure, sleep or vision.
7. NAD+ metabolism and arterial stiffness after long-term NMN supplementation: a 12-week RCT (Scientific Reports, 2023) Human12 weeks of NMN safely raised NAD+ markers and pointed toward more flexible arteries.
8. MIB-626, an oral NMN formulation, increases circulating NAD+ in middle-aged and older adults (J Gerontology: Med Sci, 2023) HumanA pharmaceutical-grade NMN produced large, dose-related jumps in NAD+ in overweight adults aged 55–80, and was well tolerated.
9. Efficacy of oral NMN on glucose and lipid metabolism in adults: a systematic review & meta-analysis (Critical Reviews in Food Science & Nutrition, 2024) ReviewThe honest counter-weight: pooling the trials, NMN reliably raises NAD+, but clear blood-sugar/cholesterol benefits in healthy people aren’t proven yet. NMN’s job — refilling NAD+ — is settled science; some downstream effects are still being studied.

2. Animal studies — why this isn’t placebo

A mouse can’t believe its way to better health. It doesn’t know it’s in a study, can’t read a label, and has no expectations to fool. That’s what makes animal evidence so powerful — and the NMN animal results are striking.

1. Long-term NMN mitigates age-associated physiological decline in mice (Cell Metabolism, 2016) AnimalThe landmark study: a full year of NMN kept mice leaner, more energetic and more physically active as they aged — with no toxicity.
2. Impairment of an endothelial NAD+–H2S network is a reversible cause of vascular aging (Cell, 2018) AnimalNMN regrew the tiny blood vessels feeding aged muscle and boosted running endurance by roughly 60% — a near-youthful blood supply restored.
3. NMN treats the pathophysiology of diet- and age-induced diabetes in mice (Cell Metabolism, 2011) AnimalIn mice made diabetic by a junk-food diet or by old age, NMN restored NAD+ and reversed the blood-sugar problems.
4. NMN reverses vascular dysfunction and oxidative stress with aging in mice (Aging Cell, 2016) AnimalNMN restored flexible, healthy arteries in old mice and reduced the oxidative damage that stiffens blood vessels with age.
5. Declining NAD+ induces a pseudohypoxic state disrupting nuclear–mitochondrial communication during aging (Cell, 2013) AnimalRestoring NAD+ made the muscle “power plants” of old mice look young again in just over a week.
6. NAD+ repletion improves mitochondrial and stem cell function and enhances lifespan in mice (Science, 2016) AnimalBoosting NAD+ (here with the sister precursor NR) rejuvenated worn-out muscle stem cells and made the animals live measurably longer.
7. NMN rescues brain blood flow and improves cognitive function in aged mice (Redox Biology, 2019) AnimalTwo weeks of NMN restored healthy blood flow in the brains of very old mice and measurably improved memory.
8. NMN protects the heart from ischemia and reperfusion (PLoS One, 2014) AnimalMice given NMN kept their heart NAD+ up and suffered substantially less heart-muscle damage.

3. NAD+, energy & fatigue

NAD+ is the spark that lets your mitochondria turn food into ATP — the actual fuel your cells spend. When it falls, the lights dim. This is the research on energy, tiredness and getting up-and-go back.

1. Effect of 12-week NMN on sleep quality, fatigue and physical performance in older adults: an RCT (Nutrients, 2022) HumanNMN improved lower-body strength and cut daytime drowsiness and tiredness — the closest human trial to the everyday “I’m exhausted” complaint.
2. CoQ10 plus NADH on fatigue and quality of life in chronic fatigue syndrome: an RCT (Nutrients, 2021) HumanIn 207 people with chronic fatigue, NAD+ support significantly reduced perceived fatigue and improved quality of life and sleep.
3. Oral NADH versus conventional therapy for chronic fatigue syndrome (PR Health Sciences Journal, 2004) HumanAn early trial where chronic-fatigue patients on NADH had a sharp drop in symptoms in the first months versus standard care.
4. Why NAD+ declines during aging: it’s destroyed (Cell Metabolism, 2016) ReviewExplains the root cause: you don’t make less NAD+ with age — an enzyme called CD38 increasingly destroys it, which is why energy fades.
5. Emerging therapeutic roles for NAD+ metabolism in mitochondrial and age-related disorders (Clinical & Translational Medicine, 2016) ReviewLays out why refilling NAD+ is a promising way to repair tired, failing mitochondria and counter age-related decline.
6. The role of NAD+ metabolism and mitochondria in aging and disease (npj Metabolic Health & Disease, 2025) ReviewAn up-to-date map tying low NAD+ directly to worn-out mitochondria — and the precursors (like NMN) being tested to fix it.

4. NAD+, pain & the nervous system

Pain isn’t just “in the joints.” It runs through nerves that need NAD+ to survive and stay calm. Here’s the research on NAD+, nerve protection and pain signaling.

1. An NAD+ precursor relieves the painful dimensions of chemotherapy-induced peripheral neuropathy in rats (Pain, 2017) AnimalAn NAD+ booster (NR) prevented and partly reversed the burning touch-sensitivity caused by a chemo drug.
2. NR relieves chemo-induced neuropathy and enhances tumor suppression in tumor-bearing rats (Pain, 2020) AnimalThe same NAD+ precursor reduced nerve pain and protected nerve fibers — without blunting the chemo’s effect.
3. Nicotinamide riboside opposes type 2 diabetes and neuropathy in mice (Scientific Reports, 2016) AnimalRaising NAD+ improved blood sugar and protected the small sensory nerves that get damaged in diabetic nerve disease.
4. The SARM1 axon-degeneration pathway: control of the NAD+ metabolome regulates axon survival (Current Opinion in Neurobiology, 2020) ReviewReveals the switch: injured nerves die when their NAD+ is burned up — so keeping NAD+ high helps keep nerves alive.
5. NMN alleviates inflammation and oxidative stress by decreasing COX-2 in macrophages (Frontiers in Molecular Biosciences, 2021) LabNMN lowered COX-2 — the very same inflammation pathway targeted by ibuprofen and other NSAID painkillers.
6. NR augments the aged human muscle NAD+ metabolome and induces anti-inflammatory signatures (Cell Reports, 2019) HumanIn older adults, an NAD+ precursor switched on anti-inflammatory gene programs in muscle and lowered inflammatory signals in the blood.

5. The inflammation–NAD+ loop (CD38)

This is the mechanism at the heart of Inner Heal. As you age and inflammation rises, an enzyme called CD38 switches on and devours your NAD+. Less NAD+ means less energy and weaker inflammation control — which fuels more CD38. It’s a loop. Here’s the science behind it.

1. CD38 dictates age-related NAD+ decline and mitochondrial dysfunction (Cell Metabolism, 2016) AnimalThe smoking gun: CD38 is the main reason NAD+ falls with age. Remove it, and aging mice kept high NAD+ and healthy mitochondria.
2. Senescent cells promote tissue NAD+ decline during aging via CD38+ macrophages (Nature Metabolism, 2020) AnimalConfirms the loop: aging, inflammatory immune cells carrying CD38 actively drain the body’s NAD+.
3. CD38 in immune cells is induced during aging and regulates NAD+ and NMN levels (Nature Metabolism, 2020) AnimalShows inflammatory cells that accumulate with age chew up both NMN and NAD+ — directly linking “inflammaging” to energy loss.
4. The pharmacology of CD38/NADase: an emerging target in diseases of aging (Trends in Pharmacological Sciences, 2018) ReviewArgues that protecting NAD+ from CD38 is a credible strategy against aging- and inflammation-related disease.
5. A potent CD38 inhibitor reverses age-related metabolic dysfunction by restoring NAD+ (Cell Metabolism, 2018) AnimalProof of principle: shut down CD38, NAD+ comes back and age-related decline reverses.
6. SIRT1 inhibits the inflammatory response partly via the NLRP3 inflammasome (Molecular Immunology, 2016) LabShows the flip side: the NAD+-powered enzyme SIRT1 puts the brakes on inflammation — so more NAD+ means better inflammation control.

6. Fibromyalgia — the cellular-energy connection

For years fibromyalgia was dismissed as “all in your head.” The research below tells a different story: failing mitochondria, low cellular energy, oxidative stress and real, measurable inflammation — the exact problems NAD+ exists to solve. (These are studies of fibromyalgia and of cellular-energy support; they are not NMN trials — see the note at the top.)

1. Can coenzyme Q10 improve clinical and molecular parameters in fibromyalgia? (Antioxidants & Redox Signaling, 2013) HumanA placebo-controlled trial: supporting cellular energy significantly cut pain, fatigue and morning tiredness — and switched mitochondrial genes back on.
2. Is inflammation a mitochondrial-dysfunction-dependent event in fibromyalgia? (Antioxidants & Redox Signaling, 2013) HumanIn women with fibromyalgia, struggling mitochondria directly triggered inflammation — an “energy failure → inflammation” loop you can measure.
3. Oxidative stress correlates with symptoms in fibromyalgia: coenzyme Q10 effect (PLoS One, 2012) HumanFibromyalgia patients had low cellular energy (ATP) in their cells; restoring it eased symptoms.
4. Oxidative stress and mitochondrial dysfunction in fibromyalgia (Neuroendocrinology Letters, 2010) ReviewOne of the first papers to argue fibromyalgia involves real, physical mitochondrial problems — not imagination.
5. Oxidative stress, mitochondrial dysfunction and inflammation: common events in the skin of fibromyalgia patients (Mitochondrion, 2015) HumanEven in skin cells, the energy-and-inflammation problem showed up — and the worse it was, the worse the pain.
6. Brain glial activation in fibromyalgia — a multi-site PET investigation (Brain, Behavior, and Immunity, 2019) HumanBrain scans delivered the proof: fibromyalgia patients have real, measurable inflammation in the brain.
7. The prevalence and characteristics of fibromyalgia in the general population (Arthritis & Rheumatism, 1995) HumanThe landmark population study showing fibromyalgia overwhelmingly affects women and climbs through midlife — the 50s and beyond.
8. Increased oxidative stress and CoQ10 deficiency in fibromyalgia: amelioration of fatigue by ubiquinol (Redox Report, 2013) HumanA clear energy deficit drove fatigue — and restoring the cell’s energy machinery reduced it.

7. Why NAD+ matters more as you age (especially for women)

If NAD+ never declined, none of this would matter. But it does — and the research shows midlife women may feel it most, as the metabolic protection of estrogen fades and inflammation rises.

1. Age-related NAD+ decline (Experimental Gerontology, 2020) ReviewThe authoritative summary: NAD+ — the molecule your cells need to make energy — falls as you age.
2. Age-associated changes in oxidative stress and NAD+ metabolism in human tissue (PLoS One, 2012) HumanMeasured in actual human tissue: NAD+ drops strongly with age in both men and women — direct proof the tank runs low.
3. Association of human whole-blood NAD+ content with aging (Frontiers in Endocrinology, 2022) HumanA modern blood study confirming the decline — newer evidence backing the older tissue findings.
4. Menopause is associated with worse postprandial metabolism and metabolic health (EBioMedicine, 2022) HumanIn over 1,000 women, the estrogen drop at menopause came with worse blood-sugar control and rising inflammation — the exact backdrop NAD+ decline plays out against.
5. NMN supplementation reverses the declining quality of maternally aged oocytes (Cell Reports, 2020) AnimalNMN partly reversed age-related decline in older females — more evidence that refilling NAD+ counters the biology of aging.

Note on the evidence: Studies are labeled Human, Animal, Review or Lab so you can weigh them yourself. Animal and laboratory findings don’t always translate to humans, and several human studies are small or early-stage. Some studies used nicotinamide riboside (NR), a related NAD+ precursor, rather than NMN. NMN has not been tested in a dedicated fibromyalgia clinical trial; the fibromyalgia research here concerns the underlying biology and cellular-energy support, not NMN itself.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. The information on this page is provided for educational purposes and is not medical advice. Talk to your doctor before starting any supplement, especially if you are pregnant, nursing, taking medication, or managing a health condition.