I did a deep dive on this a couple years ago, tried a Niagen (NR) + Collegen called Nectar7. Energy levels always feel subjective to me, but it did have noticeable results on my skin. It is a form of Niacin and has the same benefits and also, like a lot of supplements, a caution about the dosages. Chris Masterjohn gives the best breakdowns on how various supplements actually work and what to be aware of when taking them.
I ultimately came to the same conclusion as him, it's always best to get vitamins and minerals from real whole foods, but there are times when a supplement can help if you view it as it's name implies, to supplement the other things you're doing health wise and not as a magic bullet.
The real magic bullets don't cost anything and don't come in a bottle, they're low carb/keto + fasting.