Evidence? No bad effects?

Who has before and after biomarker and/or objective measurement evidence
demonstrating the effectiveness of NAD infusions, or NAD precursors and boosters like patches, buccal (NADPlus), supplements etc in humans?

Measures might include:
DNA methylation, 
Lab tests including inflammation, LevineCramer spreadsheet, complete blood count and metabolic panel (glucose, immune, markers of health for elements like liver and kidney)
Cognitive
Physiological

- and –

Do you have evidence of adverse events, or no harm being done.  Things like
   Lab measures for issues like liver and kidney
   Would we become dependent on it – would there be feedback inhibition as can happen with testosterone and other hormones if we’re not actually deficient? 
   Would it compete with another therapy for a clearance channel, resulting in a higher amount in the system?  Example: Metformin drug advisory says not to take metformin with grapefruit juice.  I believe metformin and some other drugs have the same effect.  
   Combining aging therapies can be complicated -- what about that.
   Would it somehow result in replication senescence – example: a therapy that stimulates stem cell production and draws on the capacity to produce later

- and –

Do you have info on testing for NAD levels, like Longevity Bridge?

Thanks.