The Summary
Researchers conducted a systematic review of 113 studies (33 human, 80 rodent) investigating NAD+ boosters like NR and NMN. While rodent studies showed metabolic and functional improvements, human trials yielded mixed results. Although oral NR and NMN reliably increased blood NAD+ levels and were well-tolerated over weeks or months, their actual impact on functional, metabolic, or vascular health remains inconsistent or null. Furthermore, the review found zero clinical outcomes trials testing popular intravenous (IV) or intramuscular (IM) NAD+ therapies for wellness, highlighting a major gap between marketing claims and scientific evidence.
Why this is interesting
NAD+ infusions and oral supplements are heavily hyped as the ultimate youth elixir, with wellness clinics promising dramatic cellular rejuvenation. This review injects some reality into the trend: yes, oral supplements successfully raise NAD+ levels, but we still do not know if this translates into real-world health benefits like more energy or better metabolism. Crucially, popular and expensive IV NAD+ therapies have virtually no clinical data supporting their efficacy. For consumers, the takeaway is clear: do not waste money on unproven IV drips, and approach oral NAD+ supplements with cautious optimism.