Does NAD+ Help Long Covid? What the Research Shows Yes, emerging research suggests that boosting NAD+ levels may help alleviate some Long Covid symptoms, particularly fatigue, brain fog, and sleep disturbances. A recent 2025 clinical trial found that while NAD+ supplementation didn't drastically change overall cognitive scores compared to a placebo, participants who took it for at least 10 weeks reported noticeable improvements in their energy levels, sleep quality, and mood. By supporting cellular energy production and reducing inflammation, NAD+ offers a promising avenue for those struggling with the lingering effects of the virus. Understanding the NAD+ and Long Covid Connection If you have been battling Long Covid for months, you know the profound exhaustion and mental cloudiness that can make even simple daily tasks feel insurmountable. You are not alone, and the scientific community is actively searching for answers. One of the most compelling areas of current research focuses on a molecule called Nicotinamide Adenine Dinucleotide, or NAD+. NAD+ is a crucial coenzyme found in every cell of your body. It plays an essential role in energy metabolism, DNA repair, and cellular defense mechanisms. When your body fights off a severe viral infection like COVID-19, it consumes massive amounts of NAD+ to fuel the immune response and repair damaged tissues. This intense demand can lead to a significant depletion of NAD+ levels, leaving your cells struggling to produce the energy (ATP) needed for normal function. This cellular energy crisis is increasingly believed to be a core driver of the persistent fatigue and brain fog that characterize Long Covid. What the Latest Clinical Trials Reveal The scientific understanding of NAD+ in the context of Long Covid is rapidly evolving. A landmark 2025 randomized controlled trial published in eClinicalMedicine (part of The Lancet Discovery Science) investigated the effects of high-dose nicotinamide riboside (NR), a precursor that boosts NAD+ levels, in patients with Long Covid. The study, conducted at Massachusetts General Hospital, aimed to see if restoring NAD+ could improve cognitive function and ease common symptoms. The findings offer a nuanced but hopeful picture. While the study did not show major differences in primary cognitive scores between the treatment and placebo groups over the initial period, a deeper look at the data revealed significant benefits for those who stayed on the supplement longer. In exploratory analyses of participants who took the NAD+ booster for at least 10 weeks, researchers observed marked improvements in self-reported fatigue, sleep quality, and depressive symptoms. Furthermore, these individuals showed better performance on tasks related to executive functioning—the mental skills needed to plan, organize, and focus. These results suggest that while NAD+ might not be an overnight cure, consistently supporting your cellular energy pathways over time can help your body gradually recover its vitality and mental clarity. Beyond NAD+: The Role of Medicinal Mushrooms in Recovery While boosting NAD+ is a vital step in addressing the cellular energy deficit, Long Covid is a complex, multi-system condition. It often involves ongoing neuroinflammation, immune dysregulation, and autonomic nervous system dysfunction. To achieve comprehensive healing, many researchers and clinicians are looking toward synergistic natural therapies, particularly the use of specific medicinal mushrooms. A comprehensive 2026 review published in Sage Journals , titled "Long COVID: From Mechanisms to Natural Therapies," highlights the profound potential of these natural compounds. The review specifically cites Lion's Mane for its ability to support the autonomic nervous system, which is often thrown out of balance by the virus, leading to symptoms like heart palpitations and dizziness. Lion's Mane for Brain Fog and Neuroregeneration The cognitive impairment associated with Long Covid, often described as "brain fog," can be one of the most distressing symptoms. Lion's Mane ( Hericium erinaceus ) has emerged as a powerful ally for brain health. Research demonstrates that specific compounds in Lion's Mane, known as hericenones and erinacines, actively stimulate the synthesis of Nerve Growth Factor (NGF) in the brain. NGF is a protein crucial for the growth, maintenance, and survival of neurons. By promoting neuroregeneration and reducing neuroinflammation, Lion's Mane can help clear the mental fog, improve focus, and support memory consolidation. Cordyceps for Deep Cellular Energy If NAD+ helps provide the raw materials for energy, Cordyceps helps optimize the factory. Cordyceps is renowned for its ability to enhance the body's production of adenosine triphosphate (ATP), the primary energy currency of our cells. A recent 2024/2025 randomized controlled trial conducted in Hong Kong focused specifically on a Cordyceps sinensis extract (Cs4) in patients with Long Covid. The re