34. Best Supplement for Longevity: Creatine, NAD, HRT, or Something Else Entirely with Dr. Mark Su

What's the single best supplement for longevity? Dr. Mark Su gets asked this question constantly, and in this solo episode he finally sits down and gives a real answer. It depends on what you're after. Want to feel younger and better? Creatine is the cheap, convenient place to start. Want something more personalized? Hormone replacement therapy, guided by testing, becomes the conversation. Want to actually be younger, not just feel it? NAD comes into play. Want precision instead of a one-size-fits-all answer? Biological age testing shows you your rate of aging and, more importantly, which system in your body is the weakest link holding everything else back. Then Dr. Su tries something different. He takes the exact same question to Claude, his AI tool of choice, and reads through the response live on the show. What comes back is a four-tier hierarchy of evidence, from robust epidemiologic data at the top all the way down to practitioner opinion with weak or no data behind it, the tier where most peptides and longevity stacks actually live. The most defensible single answer that holds up under real scrutiny turns out to be structured exercise targeting VO2 max. But this episode isn't really just about supplements. It's about the difference between advice that sounds confident and advice that's actually evidence-backed, and why practitioners, whether they're working in longevity medicine or treating complex chronic illness through functional medicine, owe their patients honesty about what the data can and can't tell us. No overselling, no fear-mongering, no pretending there's more certainty than there is. If you've ever wanted a straight answer to "what should I actually take," or you've quietly wondered whether your own practitioner is being fully honest with you about the evidence behind your plan, this one's for you. In this episode: Dr. Su's real answer to the "one best supplement for longevity" question Creatine, NAD, and hormone replacement therapy, and when each actually fits Biological age testing and finding your body's weakest link Using AI to rank the real evidence behind longevity interventions Why VO2 max training is the most defensible single answer with real data behind it The case for honesty and transparency over hype in functional and longevity medicine Connect with RootSeek: Get your free Lab Results Guide: Download at rootseekhealth.com/labs/ Have a question for Dr. Su? Once a month, Dr. Su opens one hour to five people only. Real questions, real answers, real direction. Book your spot: rootseekhealth.com/askdrmark Subscribe and Leave a Review: If Functional Medicine Reality has been valuable to you, please subscribe and leave a review. It helps more patients find the answers they have been searching for. If you're focused on optimizing your health long-term, we have something coming for you. Stay connected at rootseekhealth.com . Instagram: @rootseekhealth Disclaimer: This podcast is for educational purposes only. Information discussed is not intended for diagnosis, curing, or prevention of any disease and is not intended to replace advice given by a licensed healthcare practitioner. This podcast and its guests may have direct or indirect financial interests associated with products mentioned.