\u201cEven patients in their twenties have symptoms of brain fog, fatigue, chronic inflammation, and chronic infection post-Covid,\u201d Khan says. In her clinical experience, some report improvements in energy, mental clarity, migraines, and circadian disruption after using NAD-related therapies, especially during periods of high physical or cognitive stress.<\/p>\n
\u201cI have a lot of fitness enthusiasts [as patients], who recover better after an injury or an intense exercise routine,\u201d Khan adds. \u201cThey feel like they can get more reps in, swim more laps, and their tissues aren\u2019t as easily tired.\u201d<\/p>\n
Early research<\/a> is also exploring NAD+\u2019s role in neurodegenerative disease, inflammatory pain pathways, and addiction, though much of this work remains preliminary. In people with existing degenerative conditions\u2014such as Parkinson\u2019s disease, sarcopenia, or Alzheimer\u2019s disease<\/a>\u2014NAD precursors may help slow decline. What remains unclear is whether starting supplementation can prevent disease or significantly alter the aging trajectory.<\/p>\n Safety, Side Effects, and Considerations<\/p>\n Among NAD+ boosters, NR supplements have the most robust safety data. They have been studied in doses ranging from 1,000<\/a> to 3,000 milligrams per day<\/a> in healthy adults, with minimal to no side effects reported.<\/p>\n Although NMN has also been widely studied, it was sidelined for years by regulatory issues. In 2022<\/a>, the US Food and Drug Administration stated that NMN couldn\u2019t be sold as a supplement because it was being investigated as a drug. That decision was later reversed in 2025<\/a>.<\/p>\n Niacin, another NAD+ precursor, is effective but less popular because high doses can cause flushing, where the cheeks become red and warm, and an increased heart rate due to vasodilation. While uncomfortable, this reaction isn\u2019t generally dangerous.<\/p>\n