Positives

• One person found that NAD+ IV infusions provided a “10-15% increase in baseline energy,” which, while not groundbreaking, was considered a valuable boost in energy levels Reddit.
  
  

Negatives

• Long COVID patients on nicotinamide riboside (oral NAD+ precursor) commonly see no significant improvement in cognitive function versus placebo, with primary fatigue, sleep and mood outcomes also failing to separate from placebo eClinicalMedicine.
• Patients on oral NAD+ capsules often describe minimal change despite the marketing — the molecule largely doesn’t survive intact to systemic circulation due to limited bioavailability Clarus Health.
• Sublingual NAD+ products are positioned as faster-absorbing, but patients commonly see no meaningful long-term effectiveness difference versus oral, and no compelling evidence that sublingual offers a major advantage.
• Even the Long COVID NR effort’s positive signals came only from exploratory within-group analyses, not placebo-controlled comparisons, matching patient forum reports of underwhelming results from oral and sublingual products ScienceDaily.

Hurdles & Side Effects

• One patient highlighted the complexity of managing mast cell activation syndrome (MCAS) when considering NAD+ therapy, emphasizing the need to understand how mast cells release substances that can affect treatment outcomes Reddit.