Supplements claiming to slow aging are being scrutinized for their effectiveness. Some reports suggest certain supplements, such as multivitamins or NAD+ supplements, may have a limited impact on biological age, but it is unclear if they provide long-term benefits or increase lifespan. The use of these supplements as part of a "longevity stack" is being explored, with some individuals, including one who has spent heavily on biohacking, seeking to slow aging, but the overall efficacy of these methods is uncertain.