{"publication_id":"1ece772b-d3e4-4ad0-b090-ac7e9ea4a1d6","screening":{"identified":36,"screened":36,"excluded":0,"included":36,"included_or_retained":36,"flow":["identified","screened","excluded_with_reasons","included"],"wording":"36 candidate receipts retained after source retrieval, deduplication, and topic filtering. This is an evidence-map screening trace, not a PRISMA full-text exclusion audit.","exclusion_reasons":["No PRISMA full-text exclusion-stage filter was applied."]},"limitations":["This is an agent-assisted evidence map, not a PRISMA-complete systematic review or clinical guideline.","It is not PROSPERO-registered and should not be read as medical advice.","Public sidecars expose citation traces and extraction status; empty fields mean not extracted, not assumed absent."],"contradictions":["The evidence profile indicates that while preclinical evidence for rapamycin's anti-aging potential is compelling, human data from controlled trials predominantly show null or inconsistent effects on clinical healthspan endpoints.","Aging represents the single greatest risk factor for the leading causes of morbidity and mortality worldwide, including cardiovascular disease, cancer, neurodegeneration, and metabolic dysfunction. The geroscience hypothesis posits that targeting the fundamental biological mechanisms of aging could simultaneously delay or prevent multiple age-related conditions, offering a paradigm shift from disease-specific interventions to a unified approach against the underlying process itself (Cruz-Jentoft 2019). The question of whether pharmacological interventions can meaningfully extend human healthspan — the period of life spent in good health — has moved from speculative fiction to a central preoccupation of translational medicine. Despite decades of research, no intervention has been approved specifically for the indication of slowing human aging, leaving an enormous unmet clinical need. The stakes are high: even a modest delay in the onset of age-related disability could yield substantial reductions in healthcare burden and improvements in quality of life for millions. It is within this context that rapamycin effects have attracted intense scientific and public interest as a candidate geroprotective agent. The drug rapamycin, an mTOR inhibitor originally developed as an immunosuppressant, has emerged as one of the most studied molecules in the biology of aging, yet the translation from preclinical promise to human clinical benefit remains incomplete and contested. The current moment is therefore one of both excitement and caution, as the field seeks to determine whether rapamycin effects can fulfill their early promise in rigorous human trials.","Despite the growing number of clinical investigations, several critical unresolved questions surround rapamycin effects as a potential geroprotector. The translation of robust preclinical lifespan extension to human healthspan benefit is not guaranteed, and the tension between mechanistic promise and clinical reality is evident across the evidence base. For example, preclinical studies have shown that rapamycin treatment increases survival and expression of the anti-aging klotho protein in elderly mice (Szoke 2023), yet the direct human RCT evidence for functional benefit in older adults remains sparse and inconclusive (Stanfield 2026). Dose-response relationships are poorly characterized in the aging context: the PEARL trial used 5 mg and 10 mg weekly doses (Moel 2025), while the RAPA-EX-01 trial used 6 mg weekly (Stanfield 2026), and the ERAP protocol uses 7 mg weekly (Svensson 2024), yet whether these doses are optimal for geroprotection — or whether they carry meaningful immunological or metabolic risks — has not been established. The duration of treatment required for benefit is also unclear: preclinical evidence suggests that even transient treatment can produce lasting effects (Bitto 2016), but human trials have typically been limited to weeks or months rather than years. Population specificity adds further complexity: rapamycin effects may differ between healthy older adults, patients with neurodegenerative disease, transplant recipients, and cancer survivors, yet most trials enroll narrow populations that limit generalizability. The question of whether rapamycin effects on immune function, metabolism, and tissue homeostasis represent a net benefit or a net risk in aging populations — and under what dosing and scheduling conditions — remains the central unresolved issue in the field.","This synthesis aims to address these gaps by providing a structured, cross-domain evaluation of rapamycin effects across the available evidence base. Across 36 curated reference papers, the evidence shows a context-dependent profile: positive signals appear in longevity and functional endpoints, negative signals emerge in specific safety and comorbidity contexts, and null findings dominate in several outcome categories. The synthesis identifies cross-study disagreements across outcome classes, reflecting fundamental disagreements about whether rapamycin effects are beneficial, harmful, or neutral depending on the population, dose, duration, and endpoint studied. By separating mechanistic evidence from clinical trial evidence, and by weighting each finding according to study design, directness, and effect direction, this work seeks to move beyond narrative summaries toward an actionable evidence architecture. The clinical-versus-mechanistic separation is particularly important because the tension between preclinical promise and human trial results is a recurring source of confusion in the field: preclinical studies consistently show rapamycin effects on lifespan and healthspan markers, while human trials report mixed or null results on functional endpoints. This synthesis will also examine the dose-response question, the duration-of-treatment question, and the population-specificity question with the aim of identifying boundary conditions under which rapamycin effects may be most likely to translate into clinical benefit. The rapamycin effects anti-aging case as currently constituted is incomplete: mechanistic plausibility coexists with mixed or sparse human-RCT evidence, and the boundary conditions remain to be established. By mapping these tensions explicitly and identifying the highest-priority evidence gaps, this synthesis aims to inform the design of future trials and to clarify the conditions under which rapamycin effects might move from promising preclinical biology to validated clinical geroprotection.","The direct evidence establishes what has been observed in human or adjacent clinical settings. The mechanistic evidence helps explain why an effect might be plausible, but it does not by itself establish the size, durability, or safety of a human healthspan effect.","The study-level structure also prevents selective emphasis. Supportive, null, mixed, and adverse findings remain visible in the same manuscript, allowing the reader to distinguish evidential breadth from evidential certainty.","In a preclinical study by Correia-Melo and colleagues, the effects of rapamycin on healthspan and frailty were investigated in nfκb1 −/− mice, a model of accelerated aging and chronic inflammation. The study compared nfκb1 −/− mice fed a control diet (n = 44) with those receiving rapamycin-supplemented feed. Translational relevance to humans remains uncertain. A key finding was that rapamycin treatment prevented age-related frailty in these mice, as evidenced by significant differences in frailty scores (P < 0.01, P < 0.001) between the groups over the study duration. Translational relevance to humans remains uncertain. However, this improvement in healthspan metrics occurred without a corresponding extension of lifespan, highlighting a dissociation between functional outcomes and longevity in this model.","The quantitative findings from Correia-Melo et al. demonstrate a mixed effect profile. Rapamycin significantly improved markers of frailty and healthspan, with multiple endpoints reaching statistical significance (P < 0.01, P < 0.001). Despite these functional improvements, the intervention did not impact the chronic inflammatory state (inflammaging) characteristic of the nfκb1 −/− model, nor did it alter overall survival. This suggests that rapamycin's benefits in this context may be mediated through mechanisms independent of direct lifespan extension or broad suppression of NF-κB-driven inflammation.","By contrast, the findings from Correia-Melo et al. present a tension within the preclinical evidence base. While rapamycin conferred clear functional benefits in preventing frailty, its failure to impact inflammaging or lifespan in nfκb1 −/− mice suggests that its efficacy may be contingent on the specific pathological context. This study's results indicate that the therapeutic window and target pathways for rapamycin in cardiometabolic aging may differ from those implicated in pure longevity interventions, underscoring the complexity of translating preclinical findings to broad clinical application.","As this protocol describes planned rather than completed research, quantitative findings regarding effect sizes, p-values, and sample sizes are not yet available from this source. The absence of completed outcome data means that the null effect direction currently characterizes this evidence entry. The protocol's focus on kidney transplant recipients—a population typically excluded from rapamycin anti-aging investigations due to baseline immunosuppression—highlights the context-dependent nature of rapamycin's immune effects. Whether rapamycin can paradoxically enhance vaccine responses in immunocompromised individuals remains an open question pending trial completion.","The current evidence base presents a notable tension: while mechanistic plausibility supports rapamycin's potential immunomodulatory benefits, the available clinical data remain limited to protocol descriptions without outcome validation. The RIVASTIM trial (Tunbridge 2022) exemplifies the gap between preclinical promise and clinical evidence generation. This tension is not unique to immune outcomes but reflects a broader pattern across the rapamycin literature, where mechanistic insights from preclinical models await confirmation in human trials. The context-dependent nature of rapamycin's immune effects—potentially enhancing responses in some populations while suppressing them in others—complicates straightforward synthesis of the available evidence.","The curated corpus on rapamycin's effects on immune and inflammatory outcomes comprises four studies with heterogeneous designs, populations, and effect directions (Wang 2022; Drion 2018; Ge 2023; Withers 2025). Study designs include one preclinical investigation (Drion 2018) and three observational cohorts (Wang 2022; Ge 2023; Withers 2025), with the latter enrolling adult populations. Duration and dosing vary considerably, ranging from nanofiber-based local delivery in a stent model (Wang 2022) to immunomodulatory rapamycin dosing in cancer vaccine trials (Withers 2025, NCT01536054). Reported effect directions span null (Wang 2022), mixed (Drion 2018; Ge 2023), and unclear (Withers 2025), indicating substantial heterogeneity in the evidence base."]}