Core Insights - The article emphasizes the importance of understanding key factors when choosing NAD+ products, particularly focusing on the types of precursor substances used, namely NMN and NR, which have distinct characteristics affecting stability and absorption [1][3]. Group 1: Product Composition - The main NAD+ supplements contain either NMN or NR, with NMN having a larger molecular weight and potentially better stability, while NR has a smaller molecular weight and is theoretically easier to absorb [1]. - Quality products should clearly indicate the specific form and content of the precursors used [1]. Group 2: Production Process and Purity - The production process and purity of NAD+ precursors are crucial, with high-purity products typically produced through biological fermentation, which, although more expensive, ensures safety and purity [3]. - Consumers are encouraged to check for third-party testing reports that detail effective ingredient content, heavy metal residues, and microbial limits, with a purity level of 98% or higher being ideal [3]. Group 3: Certification and Pricing - Certification information is vital, as NAD+ supplements do not require the same rigorous approval as drugs; however, certifications like FDA's GRAS and GMP can provide assurance regarding safety and production standards [5]. - The market price for NAD+ products varies significantly, influenced by factors such as raw material source, purity level, dosage form, and brand premium, with consumers advised to avoid both the most expensive and excessively cheap options [5].