Niagen is a dietary supplement manufactured by a company called LiveCellResearch and sold over the internet on their official website LiveCellResearch.com. It has already been tested on not just animals but also humans and the human trial that it was involved with was sponsored by another company called ChromaDex and on the official website of ChromsDex you can find information in regard to Niagen.
It is a very popular dietary supplement but like any supplement, individual results will vary and some individuals benefit more from it than others. As a general rule of thumb, people over the age of 40 or 50 would benefit more from it because Niagen helps the most with the mitochondrial health, reversing the effects of aging on the body but also the mind, improving energy production and also offering antioxidant benefits or properties.

When we are young we don't have that many problems with our cells and with the mitochondrial because our cells are relatively young and healthy.
As we age though, they age as well as they suffer damage caused to them by oxidants which are naturally made in the body but also caused by smoking, stress, sickness, unhealthy eating, sleep deprivation, pollution, etc. People that have such unhealthy habits like smoking in their lives are more at risk of oxidative stress and the health problems that oxidants and oxidative stress can contribute to, such as faster aging skin, the decline in mitochondrial health and function, damage also sustained by neurons and cognitive decline, heart disorders, cardiovascular disorders, cancer, etc.
Niagen works in a simple way and the most important thing is that it really does work since it has been proven to work in a clinical trial.
I know most of you are used to supplements lacking clinical evidence, FDA approval, etc. It's true, most supplements don't offer you any evidence.

Niagen is different and it is the first commercially available form of Nicotinamide Riboside (250mg). The NR is used as a natural precursor to synthesize NAD+ (Nicotinamide adenine dinucleotide). NAD+ is involved in the protection of cells and neurons, production of energy and the metabolism and more. Definitely a supplement worth checking out but do consult with your medic before using it, if you do decide to use it.