long term glutathione use 9 Health Benefits of Best Glutathione Supplement | 4
Description
Author Contributions Conceptualization: LLE, JKH

When exogenous pure compounds were spiked to fresh blood (Sample Type 1), recovery rates were below 100%: NAD + at 92.5%, NADH at 10%, NADP + at 80% and NADPH at 60%

Cortex 28 , 395410 (2018)

10.3390/ijms21113743 Int J Mol Sci
The effect is dose-dependent but plateaus at relatively low concentrations