If you are asking about which is more effective NMN or NAD, it really comes down to the research available for the individual compounds. David Sinclair has hinted at different activators activating different Sirtuins so it could be a case in the future that a pill combined with several activators combined would be most effective.
We have a number of customer’s currently taking both, however the main research has been focussed on NMN, so I would say that should be a priority.
If you join this Facebook group – https://www.facebook.com/groups/NMNfans/ – there is a lot of interesting feedback from NMN and NAD users.
The mild consensus on there is that NMN benefits the body with NAD benefitting the brain. There is also the below article from the Alive By Nature website related to the topic.
https://alivebynature.com/nad-for-the-brain-nmn-for-the-body/