🔬 National Institute on Aging (NIA) Interventions Testing Program

Mammalian Lifespan Extension Landscape

The NIA Interventions Testing Program (ITP) evaluates potential geroprotective agents across three independent research centers (Jackson Laboratory, Univ. of Michigan, UT Health San Antonio) using genetically heterogeneous UM-HET3 mice. This interactive application provides a unified platform to explore, filter, compare, and analyze all tested molecules, mechanistic pathways, and sex-specific responses.

About the Methodology & UM-HET3 Model: Testing is conducted in two primary stages: Stage I screens compounds at a single dose for median and maximum lifespan impact, while Stage II explores dose-response curves, late-life initiation ages, and combination treatments. Drugs are delivered in standardized rodent diet (ppm = mg drug / kg diet). The four-way cross UM-HET3 model prevents strain-specific artifacts, ensuring observed survival gains reflect generalized mammalian aging mechanisms.

Evaluated Candidates 100+ Singular & combined agents

Verified Extenders 16 15 single + 1 combination

Peak Median Gain +29% Rapamycin + Acarbose

Male-Biased Ratio 69% 11 of 16 show male preference

Comparative Efficacy Visualizer

Compare percentage median lifespan extension across all 16 statistically significant geroprotectors identified by the ITP.

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How to interact: Hover over or tap any bar to inspect specific dietary concentrations, initiation ages, and maximum lifespan impacts. Use the toggles above to compare overall peak gains against sex-stratified effects.

Master Interventions Database

Explore, filter, and sort all tested molecules: statistically verified extenders, non-extending (neutral/negative) candidates, and active pipeline compounds.

This comprehensive database aggregates over two decades of ITP survival experiments. Select a category tab to switch cohorts, use the search box to find specific drugs or targets, or click column headers to re-sort the primary lifespan rankings.

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Showing 16 entries * Click on any positive extender row to open Mechanistic & Trial Details

Sexual Dimorphism & Endocrine Reprogramming

A striking discovery of the ITP is that 11 out of 16 positive interventions demonstrate survival benefits strictly or predominantly in male mice.

Understanding sex-stratified longevity drivers is essential for translational medicine. Pharmacokinetic and metabolic analyses reveal two distinct biological mechanisms driving this male bias: hepatic steroid processing and postprandial glucose dynamics.

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Hepatic Steroid Metabolism (17-α-Estradiol)

17-α-Estradiol (17aE2) is a non-feminizing enantiomer with low affinity for classical nuclear estrogen receptors. Male UM-HET3 livers process 17aE2 into sulfated estrogenic intermediates at rates nearly 100-fold higher than female livers.

Male Gain: +19% Median Female Gain: 0% (Neutral)

This male-specific conversion suppresses hepatic inflammatory pathways, downregulates IGF-1, and improves insulin sensitivity. Females already possess native 17-β-estradiol levels that saturate these pathways.

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Glucose Dynamics & Baseline Pathology (Acarbose/Cana)

Carbohydrate-blunting agents like Acarbose (+22% male vs +5% female) and Canagliflozin (+14% male vs 0% female) show intense male bias despite higher female plasma drug concentrations.

Male Baseline: High Fasting Glucose Female Baseline: Superior Sensitivity

Control males suffer higher postprandial glucose spikes, age-associated insulin resistance, and early hepatic neoplasia. Blunting glycemic surges protects males from metabolic toxicity, whereas females maintain native glucose control into old age.

The Exceptions: Female Benefit & Equal Response

Captopril (ACE Inhibitor) The only intervention showing female-specific median lifespan extension (+4% female vs indeterminate male impact).

Rapamycin (mTORC1) Extends median lifespan robustly in both sexes (+23% males, +26% females) by acting on universal cell nutrient sensing.

Glycine (Amino Acid) Yields balanced +4% to +5% median extensions in both males and females across broad physiological pathways.

Combinatorial Geroscience & Replication Dynamics

Analyzing multi-drug orthogonal pathways, late-life intervention windows, and protocol reproducibility factors.

Combining geroprotectors that target complementary aging hallmarks yields superior longevity effects compared to monotherapies. However, clinical success relies heavily on late-life feasibility and avoiding narrow therapeutic dose windows.

Pathway Synergy

Rapamycin + Acarbose (+29%)

Rapamycin inhibits intracellular mTORC1 but can induce peripheral glucose intolerance as a side effect. Acarbose blocks intestinal carbohydrate absorption, blunting glucose surges. Co-administration mitigates rapamycin-induced metabolic dysregulation, driving the highest recorded ITP lifespan extension.

Contrast: Metformin + Rapamycin (+26%) yielded results identical to Rapamycin monotherapy alone, producing no additional benefit beyond Rapamycin monotherapy.

Late-Start Efficacy

Late-Life Initiation at 20 Months

Initiating Rapamycin or 17-α-Estradiol at 20 months of age (equivalent to ~60-65 human years) still extends median survival by 9–19% and increases 90th percentile maximum lifespan. This proves that mammalian aging trajectories remain malleable even in advanced late-life.

Demonstrates that pre-existing late-life physiological decline can be decelerated without requiring lifelong treatment.

Protocol Sensitivity

Astaxanthin & Meclizine Nuance

Astaxanthin (+12%) and Meclizine (+9.2%) extended lifespan when initiated at 12 months. However, when tested in follow-up late-start protocols (16 months) or higher doses, extensions failed to repeat.

Takeaway: Specific targets require initiation before irreversible tissue damage, and higher dietary concentrations can trigger off-target toxicity.