Dr. Karl R. Pfleger
Karl R. Pfleger, PhD is the Founder of AgingBiotech.info, an Angel Investor specializing in rejuvenation biotechnology, and a Longevity Industry Analyst with over 15 portfolio companies focused on damage repair approaches to aging. He is also the Co-organizer of VitaminDforAll.org, a nonprofit initiative that mobilized over 200 scientists and doctors to advocate for vitamin D supplementation during the COVID-19 pandemic.
Karl is known for creating the most comprehensive public database tracking over 400 companies in the aging biotechnology sector, establishing himself as a central figure in the transition of longevity research from academia to commercial development. Read An Interview with Karl Pfleger.
As the creator and maintainer of AgingBiotech.info since 2019, Karl has built a repository for “everything important in the field (outside of academia), organized.” The platform provides structured, sortable data on aging companies, conferences, books, blogs, interventions, and diagnostics, serving as a critical resource for investors, researchers, and entrepreneurs in the longevity space.
His database emerged from recognizing that while industry reports mentioned 25–40 companies in the field, his own tracking had identified over 100 companies by 2017, revealing a significant information gap even among leading institutions like the Buck Institute for Research on Aging. Watch Karl Pfleger Explains the Aging Biotech Explosion.
Karl’s investment portfolio exclusively focuses on rejuvenation biotechnology companies pursuing damage repair rather than merely slowing aging rates. His portfolio includes prominent companies such as Repair Biotechnologies, which develops gene therapy approaches to reverse atherosclerosis and Juvena Therapeutics, and Immunis Bio, both working on stem cell secretome therapeutics.
He emphasizes investing in companies targeting core aging mechanisms including senolytics for clearing senescent cells and epigenetic reprogramming technologies. Currently, 14 Phase 3 clinical trials are testing core aging therapeutics from companies in the field, marking a significant maturation of the industry he helped catalyze through early-stage investment. Watch Unlocking Longevity: The Future of Aging Biotech with Karl R. Pfleger.
During the COVID-19 pandemic, Karl co-organized the VitaminDforAll campaign with Dr. Gareth Davies, mobilizing over 200 scientists, doctors, and leading authorities worldwide to advocate for increased vitamin D supplementation. The initiative produced an open letter highlighting research showing that over 80 percent of COVID-19 patients were vitamin D deficient, suggesting that the pandemic sustained itself largely through infection of those with low vitamin D levels.
His efforts garnered support from two British MPs and international media attention, establishing vitamin D supplementation as a critical public health discussion during the pandemic. Read 110-Plus International Experts Release Open Letter: COVID-19 Preys on Those with Vitamin D Deficiency.
From 2002 to 2013, Karl worked at Google as a Research Scientist and Software Engineer, applying artificial intelligence and machine learning at scale to big data problems. Prior to Google, he consulted part-time for mySimon, which later became a division of CNET.
His transition from technology to longevity came after analyzing global problems and determining that aging, which kills 70% of people globally and over 92% in developed countries, represented the highest-leverage opportunity beyond addressing extreme poverty. This decision led him to shift fields entirely in the mid-2010s, beginning with philanthropy before moving into angel investing in 2017.
Karl has been a long-time philanthropist supporting aging research institutions, particularly the Buck Institute for Research on Aging and the SENS Research Foundation, to which he has been a major donor for over a decade. His philanthropic approach evolved into active investment when he recognized that certain strands of SENS research had matured sufficiently for commercial development, leading him to support the first generation of rejuvenation biotechnology companies. Read Donations being triple matched for SENS end-of-year fundraiser. Listen to Rejuvenation biotech – progress and potential, with Karl Pfleger.
Karl earned his PhD in Computer Science from Stanford University in 2002, specializing in Artificial Intelligence and Machine Learning. His doctoral research focused on On-line learning of predictive compositional hierarchies at the Knowledge Systems Laboratory, where he was advised by Barbara Hayes-Roth, Nils Nilsson, and Richard Fikes. His academic work resulted in multiple publications on machine learning, including collaborations with Pat Langley and contributions to foundational papers such as Irrelevant Features and the Subset Selection Problem and A Domain-Specific Software Architecture for Adaptive Intelligent Systems. He also earned his Master’s degree in Computer Science from Stanford.
Karl earned his Bachelor of Science in Engineering in Computer Science with highest honors from Princeton University in 1992. Despite Princeton’s rich tradition and heavy use of Latin in other contexts, his degree notation uses “with highest honors” rather than “summa cum laude,” a quirk he has noted with amusement.
As a thought leader in the longevity field, Karl has presented at prestigious venues including the World Bank, speaking at conferences such as Bitcoin Miami, the Government Blockchain Association Summit, and the Foresight Institute annual events. He has been featured on numerous podcasts including Longevity by Design with InsideTracker, London Futurists, and The Drug Diaries. His expertise bridges the technical aspects of aging biology with practical investment strategies, making him a sought-after voice on the commercialization of longevity research.
Karl notes that the longevity biotech sector has experienced explosive growth since 2015, with the field now including hundreds of companies targeting core aging pathologies. He distinguishes between interventions that slow aging rates through metabolic optimization, which provide modest benefits within the 10–20 year range, and rejuvenation strategies that repair accumulated damage, which hold promise for extending life beyond natural human limits.
His investment philosophy focuses exclusively on the latter approach, believing that true longevity breakthroughs require addressing multiple independent molecular pathways that deteriorate simultaneously. Read Aging Biotech Info is a Curated List of Companies in the Longevity Industry.
Karl resides in San Francisco, California, positioning himself at the epicenter of both the technology and biotechnology industries. His location in the Bay Area provides proximity to key aging research institutions including the Buck Institute and SENS Research Foundation, as well as the venture capital ecosystem supporting longevity companies. He describes the region as “ground zero” for the science, biotechnology, and entrepreneurship driving the longevity field forward.
Visit his LinkedIn profile, Liveforever.club, AgingBiotech.info, and Stanford page. Follow him on Facebook and X.