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Blog

Research commentary, precursor updates, and answers to emerging questions. Published under the NADFaq editorial standard — every post is sourced, reviewed, and independent of supplement-industry funding.

What this blog covers. The NADFaq blog tracks the clinical evidence base around nicotinamide adenine dinucleotide — not the marketing narrative. Posts summarize peer-reviewed human trials, pharmacokinetic studies, and mechanistic research across NR, NMN, niacin, nicotinamide, and IV NAD+. Each piece is scoped to a single question and cites PMIDs or DOIs inline so claims can be verified at the source.

What it does not cover. We do not recommend specific brands, run affiliate links, or publish supplement stacks. When the evidence is thin — sublingual pharmacokinetics, long-term safety, oncology interactions — we say so. When a marketing claim outruns the published data, we flag the gap rather than paper over it. Medical decisions belong in a clinical setting. These posts are a reading companion for that conversation, not a substitute for it.

Athlete mid-stride on a track at dawn, illustrating aerobic training stimulus that drives NAMPT salvage-pathway upregulation
MechanismsFeatured

Exercise vs NAD+ Precursors: How Training Raises NAD+

Aerobic and resistance training raise cellular NAD+ via NAMPT upregulation and mitochondrial biogenesis. Here is what human exercise trial data shows.

·13 min read
Abstract scientific illustration depicting NAD+ molecular decline during female hormonal transition, with teal and amber gradient
Clinical Conditions

NAD+ and Menopause: Why Female Hormonal Aging Accelerates NAD+ Decline

Estrogen regulates NAMPT and SIRT1, the central enzymes of NAD+ biosynthesis. When estrogen falls during perimenopause and menopause, NAD+ decline accelerates — here's the mechanistic and clinical evidence.

·14 min
Three labeled amber pharmacy bottles on a laboratory bench, labels reading NAD+, rapamycin, and metformin, in a clinical research setting
Comparisons

NAD+ vs Rapamycin vs Metformin: Three Longevity Interventions in Human Trials

A neutral comparison of NAD+, rapamycin, and metformin: mechanism, human trial evidence, dosing, safety, and FDA status. None is approved for longevity.

·14 min
Scientific illustration of mitochondria with molecular pathways in teal blue tones representing cellular energy dysfunction in post-viral fatigue
Clinical Trials

NAD+ in Long COVID and Post-Viral Fatigue: What Clinical Evidence Shows

Long COVID depletes NAD+ through CD38 activation, mitochondrial dysfunction, and chronic PARP demand. Here is what the clinical and mechanistic evidence shows as of 2026.

·17 min
Overhead view of three EDTA blood collection tubes on a white laboratory bench beside a folded printout of an analytical chromatogram and a chemical structure diagram
Measurement

How to Measure NAD+ Levels: Blood Tests, Biomarkers, and What Labs Actually Detect

NAD+ testing options reviewed: whole blood vs PBMC vs urinary metabolites, LC-MS vs cycling assays, accuracy of home tests, and what a normal NAD+ level even means.

·13 min
Glass vial of amber liquid on a dark laboratory bench beside a folded technical paper showing a small molecule chemical structure and a printed downward-trending graph
Mechanisms

CD38 Inhibitors: The NAD+ Longevity Target That Isn't a Supplement

CD38 is the enzyme that drains NAD+ with age. CD38 inhibitors (78c, apigenin, MK-0159) target the leak — not the supply. Here's where the research stands in 2026.

·14 min
Dosage

NMN Dosage: What the Clinical Trials Actually Used (100mg vs 250mg vs 600mg vs 900mg)

Every published human NMN trial reviewed — doses from 100 mg to 900 mg, sample sizes, durations, NAD+ responses, and what the dose-response curve actually shows.

·14 min
Overhead view of a clinical research bench showing labeled amber supplement bottles, a dose-response curve printout, and a notebook with handwritten mg/day annotations
Clinical Trials

NAD+ Precursor Dosing in Human Trials: What the Evidence Shows

Published NAD+ precursor trials used NR at 100-2000 mg/day, NMN at 250-1200 mg/day, and niacin at 50-2000 mg/day. Here's what the human data actually shows.

·11 min
Safety

NAD+ Precursor Drug Interactions: What Research Shows

Niacin-statin rhabdomyolysis risk is documented; NR/NMN concerns with chemo, anticoagulants, and methyl donors remain theoretical. Ask your clinician first.

·12 min
Clinical Trials

IV NAD+ Therapy: What the Evidence Shows

IV NAD+ plasma half-life runs 5-15 minutes, most hydrolyzed before tissue uptake. Sessions cost $300-800. Published clinical evidence remains thin.

·12 min
Close-up of a researcher's hands annotating an age-stratified tissue NAD+ concentration chart next to a fluorescence microscope slide
Mechanisms

How NAD+ Declines with Age: The Mechanistic Picture

Tissue NAD+ falls roughly 50% between age 20 and 70. CD38 upregulation, NAMPT decline, and chronic PARP activation explain most of the depletion — here is how.

·11 min
Overhead view of a research desk with handwritten notes, petri dish, and a declining-curve graph printout
Mechanisms

NAD+ Decline With Age: Why Tissue Levels Drop 50% by 70

Tissue NAD+ falls ~50% between age 20 and 70. Rising CD38, declining NAMPT, and PARP activation explain why — and what research says about restoration.

·9 min
Fundamentals

What Is NAD+? A Science-First Primer

NAD+ is a coenzyme in every living cell that fuels energy metabolism and regulates sirtuins, PARPs, and CD38. A primer on the biochemistry and why it matters.

·11 min
Two labeled glass vials labeled NR and NMN on a laboratory bench next to a pipette and a printed spectrometer readout
Comparisons

NR vs NMN: What Head-to-Head Research Actually Shows

A neutral comparison of NR and NMN — salvage-pathway entry, bioavailability, the Slc12a8 debate, human trials, and side effects. No head-to-head RCT exists yet.

·11 min
Safety

Long-Term NAD+ Precursor Safety: What We Know and Don't

The longest published NR and NMN human trials run 8-12 weeks with no serious adverse events at studied doses. Decade-scale safety data does not yet exist.

·12 min
A sublingual supplement tablet next to an oral capsule on a laboratory bench beside a printed chromatography trace and pipette
Delivery Routes

Sublingual vs Oral NMN: What the Pharmacokinetic Data Shows

Sublingual vs oral NMN bioavailability: published human PK data is sparse, and '5-10x absorption' marketing claims lack head-to-head human trials.

·11 min