Several points are important when considering a NAD+ booster supplement for you: 1. Whether it’s NMN or NR (Tru Niagen is NR) – see more on the comparison here. 2. Whether the NMN content in mg is clarified per capsule and without counting other ingredients 3. Whether the total content of NMN matches what is claimed on the packaging, eg. 15000 is really 15000 mg of NMN 4. Whether the product is made in a GMP certified facility and not certified by unknown laboratory 5. Whether the product quality is stable, the longer the expiration date, the more stable the quality is tested for   6. Whether it’s in powder form and in white (do not consume if it’s not pure white color as it could degrade or be contaminated)  7. Whether the packaging is light-proof and not in a transparent bottle or pack due to NMN’s sensitivity to light  8. Whether the purity is clarified as the top standard of at least 99% and not anything less nor the impossible 100%