What was the medicine used alongside LDN in the human trial mentioned?

What was the medicine used alongside LDN in the human trial mentioned?

So, I mentioned the Long COVID trial that we published recently. There's a substance that we use in combination called N-A-D. N-A-D is, nicotinamide adenine dinucleotide, I think I pronounced that right. 

It's a molecule you've probably heard of in high school biology.You can read more about it, but it's NAD, also frequently called NAD plus.