NADPH
Evidence Fact Sheet
Reduced NAD Phosphate
NADPH (reduced nicotinamide adenine dinucleotide phosphate) is an intracellular reductive cofactor that powers anabolic biosynthesis, glutathione recycling, and the NADPH-oxidase (NOX) ROS-generating enzymes. As an oral supplement it has no completed human RCTs; human evidence exists only for the pathways it participates in (glutathione redox, NOX enzymes). Not GRAS; novel-food status pending.
Also known as: β-NADPH · NADP-H · Reduced Nicotinamide Adenine Dinucleotide Phosphate
Overview
NADPH (reduced nicotinamide adenine dinucleotide phosphate, also β-NADPH) is the cell's principal "reducing-power" cofactor: it donates electrons for anabolic reductive biosynthesis (e.g., fatty-acid synthesis), serves as the substrate that glutathione reductase uses to regenerate reduced glutathione, and is the electron source consumed by the NADPH-oxidase (NOX) enzyme family that deliberately generates reactive oxygen species. Mechanistically it sits at the center of cytosolic and mitochondrial redox balance. As an oral dietary ingredient, NADPH is essentially unstudied: the supplement market sells roughly 10-30 mg/day, but there is no established human dosing and no completed human RCT of oral NADPH, and its oral stability and bioavailability are biologically expected to be limited. Regulatory status reflects this — in the US it is not GRAS and has no NDIN on file; the EU would likely require Novel Food authorization (none current); Brazil treats it as a case-by-case general-element registration; and China has no SAMR pathway (case-by-case review only, none approved).
Mechanism of Action
Anabolic reductive biosynthesis cofactor · GSH reductase substrate · NOX enzyme substrate · Lipid biosynthesis cofactor
Body systems: Mitochondrial & Cellular Energy · METABOLISM
Evidence-Based Benefits
Each benefit below is anchored to a specific PubMed-indexed study. Effect sizes, sample sizes, and p-values are reported as published; no values are inferred. Honest negatives and null results are kept alongside the positive findings, and disease-research populations are described as such — NADPH is not characterized as a treatment for any disease.
Oral NADPH Supplementation — Human Evidence (Honest Negative)
Null / no benefit Emerging / indexed- 10-30 mg/dayunsupported market dose
There is no completed human randomized controlled trial of oral NADPH supplementation; the ingredient's claimed benefits are extrapolated from intracellular biochemistry, not from clinical trials. A clinical-pharmacology review of reactive oxygen species underlines the central caution: broad, nonspecific antioxidant strategies have repeatedly failed in the clinic, sometimes with neutral or even detrimental outcomes — a key reason why supplying a generic reducing cofactor cannot be assumed to be beneficial. Effect size not applicable: no clinical outcome for oral NADPH has been measured.
Effect size: this study reports the direction of the finding but does not state a specific numeric effect size, so none is given here rather than estimated.
“This likely explains why systemic, nonspecific antioxidants have failed in the clinic, often with neutral and sometimes even detrimental outcomes.”
Source: PMID 32859763 · Casas 2020 · Pharmacol Rev
Glutathione Redox System (the Pathway NADPH Regenerates) — Human RCT
RCT supported- 30-35%erythrocyte/plasma GSH · high dose · P<0.05
- >twofoldNK cytotoxicity · high dose · P<0.05
NADPH is the cofactor glutathione reductase uses to convert oxidized glutathione (GSSG) back to reduced glutathione (GSH); this RCT measures the downstream pool, not NADPH itself. In 54 non-smoking adults, 6 months of oral glutathione (250 or 1,000 mg/day) raised body GSH stores by 30-35% in erythrocytes, plasma and lymphocytes (and 260% in buccal cells) at the high dose, lowered the oxidized-to-reduced glutathione ratio, and increased natural-killer cytotoxicity >twofold versus placebo. It establishes that the NADPH-dependent glutathione antioxidant system is modifiable in humans — via glutathione, not via NADPH supplementation.
Reported effect: GSH +30-35% in erythrocytes, plasma and lymphocytes and +260% in buccal cells at the high dose (P<0.05); NK cytotoxicity increased >twofold vs placebo (P<0.05)
“At 6 months, mean GSH levels increased 30-35 % in erythrocytes, plasma and lymphocytes and 260 % in buccal cells in the high-dose group (P < 0.05). ... Natural killer cytotoxicity increased >twofold in the high-dose group versus placebo (P < 0.05) at 3 months.”
Source: PMID 24791752 · Richie 2015 · Eur J Nutr
NADPH Oxidase (NOX) Family as a Disease-Associated Enzyme — Meta-Analysis
Meta-analysis supported- HR 1.93high NOX4 · overall survival · P<0.001
- OR 3.22high NOX4 · lymph-node mets · P<0.001
- 1060tumors · 16 studies
NADPH oxidases (NOX enzymes) consume NADPH to generate reactive oxygen species, and their over-activity — not a NADPH deficiency — is what associates with disease. This pooled analysis of 16 studies (1,060 malignant tumors) found higher NOX4 (NADPH oxidase 4) expression linked to shorter overall survival (HR 1.93) and more lymph-node metastases (OR 3.22). This frames NADPH-oxidase activity as a pathological signal, supporting why excess NADPH-driven ROS generation is a target to inhibit, not to feed.
Reported effect: Higher NOX4 expression associated with shorter overall survival (HR = 1.93, 95% CI 1.49-2.49, P<0.001) and more lymph-node metastases (OR = 3.22, 95% CI 2.18-4.29, P<0.001) across 1060 tumors in 16 studies
“There were 1060 malignant tumors in the 16 studies that made up this meta-analysis. In the meta-analysis, higher NOX4 expression was linked to both a shorter overall survival rate (HR = 1.93, 95% CI 1.49-2.49, P < 0.001) and a higher percentage of lymph node metastases (OR = 3.22, 95% CI 2.18-4.29, P < 0.001).”
Source: PMID 38012557 · Javadi 2023 · BMC Cancer
Targeting NADPH-Oxidase Pharmacology — Early Human Safety Signal
Emerging / indexed- n=6Phase I healthy volunteers
- P<0.05systolic BP reduction · 15 & 240 min
A network-pharmacology program targeting NADPH oxidase 5 (NOX5, alongside NOS and soluble guanylate cyclase) for acute ischemic stroke reduced infarct size in mice and, in a small Phase I cohort of healthy volunteers (n=6), produced significant systolic and diastolic blood-pressure reductions consistent with on-target vascular activity. This is early-stage human pharmacology of a strategy to inhibit NADPH-oxidase ROS generation — directionally the opposite of supplementing NADPH — and is not an efficacy trial.
Reported effect: Phase I (n=6): systolic blood pressure reduced at 15 and 240 minutes (P<0.05); diastolic pressure reduced at 60, 120 and 240 minutes (P<0.05)
“Clinical (Phase I): Systolic blood pressure reduction at 15 and 240 minutes (P<0.05, n=6); Diastolic pressure reduction at 60, 120, 240 minutes (P<0.05, n=6).”
Source: PMID 40371623 · Casas 2025 · J Am Heart Assoc
Dosage (research context · not a recommendation)
No established human dosing · supplement market 10-30 mg/day (unsupported by human RCT)
Regulatory Status · 4 Markets
- US · FDA
- NOT GRAS · not approved as dietary supplement ingredient (no NDIN filed)
- EU · EFSA
- Novel Food likely required · no current authorization
- CN · China
- NADPH: no SAMR pathway — not a listed novel food, common food, or health-food raw material; case-by-case review only, none approved.
- BR · ANVISA
- IN 28/2018 GE (general element) case-by-case registration required
Safety
NO human RCT data · safety profile unknown for oral supplementation · biology suggests stability + bioavailability limited
Related
Goals: longevity-stack
References
PubMed-indexed citations anchoring the benefit findings above. Effect sizes are reported as published.
- PMID 32859763 · Casas 2020 · Pharmacol Rev — Oral NADPH Supplementation — Human Evidence (Honest Negative)
- PMID 24791752 · Richie 2015 · Eur J Nutr — Glutathione Redox System (the Pathway NADPH Regenerates) — Human RCT
- PMID 38012557 · Javadi 2023 · BMC Cancer — NADPH Oxidase (NOX) Family as a Disease-Associated Enzyme — Meta-Analysis
- PMID 40371623 · Casas 2025 · J Am Heart Assoc — Targeting NADPH-Oxidase Pharmacology — Early Human Safety Signal
Frequently Asked Questions
1. Is there any human trial of oral NADPH supplementation?
No. There are zero completed human randomized controlled trials of oral NADPH. The benefits attributed to NADPH come from its known role inside cells (powering biosynthesis, glutathione recycling, and NADPH-oxidase enzymes), not from clinical testing of the supplement. Its oral stability and bioavailability are also expected to be limited on biochemical grounds.
2. If NADPH regenerates glutathione, does taking NADPH boost my antioxidant defenses?
That is the marketing logic, but the human evidence is for glutathione itself, not NADPH. In a 6-month RCT (n=54), oral glutathione raised body GSH stores by 30-35% in several tissues and increased NK cytotoxicity >twofold versus placebo (PMID 24791752). NADPH is the cofactor that recycles oxidized glutathione, but no trial has shown that swallowing NADPH reaches cells or changes this pathway in people.
3. Why is there caution about NADPH and reactive oxygen species?
NADPH is the fuel for NADPH-oxidase (NOX) enzymes, which deliberately make reactive oxygen species. Higher NOX4 expression has been associated with worse cancer outcomes in a meta-analysis (HR 1.93 for survival; PMID 38012557), and a clinical-pharmacology review notes that broad nonspecific antioxidant approaches have failed in the clinic, sometimes with detrimental outcomes (PMID 32859763). So more reducing cofactor is not automatically beneficial — redox balance matters.
4. Is oral NADPH approved as a dietary supplement?
No. In the US it is not GRAS and has no NDIN on file. The EU would likely require Novel Food authorization, which it does not have. Brazil treats it as a case-by-case general-element registration, and China has no SAMR pathway for it (case-by-case review only, none approved). The supplement market sells roughly 10-30 mg/day, but there is no established human dose.
Last evidence review: 2026-06-02