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Answer 8 science-backed questions. Discover your biological optimization profile and get a matched supplement protocol. Free.
Takes 60 seconds · No account required
Pick what fits most days — not your best week.
Even if it varies — pick the most common.
The trigger that fits most often.
Inflammation shows up differently in different people.
Not how you'd like it to — how it actually does.
Your circadian anchors — honest answer.
How your body actually behaves — not ideally.
After illness, exercise, or a rough week.
How it works
WhenToTakeWhat connects your goals, sleep patterns, and biomarkers to generate a supplement and lifestyle plan that actually fits your biology.
What happens if you sleep 8 hours, take creatine, and cut stress by 20%? Move the sliders — watch your score and AI health avatar update in real time. See exactly what 3 months of consistency looks like before you commit.
Your personal AI coach learns your patterns over time. Ask Edgar anything: "Why am I still waking up at 3am?" or "Can I stack ashwagandha with melatonin?" — evidence-based answers every time.
A free 60-second face scan estimates your vascular age using AI-powered rPPG technology — the same method used in clinical studies. Track how your lifestyle choices move the number.
Every meal logged, every supplement taken, every habit checked earns HP. Climb from Cell to Vital Apex across 7 tiers. Unlock 13 achievement badges. Weekly resets keep you honest — Life Pause mode forgives bad weeks.
Magnesium 30 min before bed. Vitamin D with breakfast. Creatine post-workout. Edgar builds a precise daily schedule around your sleep data, goals, and circadian rhythm — and explains the why behind every recommendation.
Choose from 12 goal-specific health journeys — sleep, testosterone, longevity, gut health, and more. Stack up to 3 parallel journeys. Edgar generates an AI rationale for your personal combination and tracks your phase progress week by week.
Supplement science
The most common questions our users ask Edgar — answered with clinical sources, organized by optimal timing.
Poor sleep is the most common health complaint WhenToTakeWhat users report. Sleep supplement science has advanced significantly in the past decade, and three compounds stand out with consistent clinical evidence. The key insight most people miss: timing matters as much as the supplement itself.
Magnesium glycinate (400mg, 30 min before bed) is the cornerstone. It activates GABA-A receptors — the same pathway targeted by sleep medications — but without dependency or next-day grogginess. The glycinate chelate crosses the blood-brain barrier more effectively than oxide or citrate forms. A 2017 randomized trial showed significant improvements in sleep efficiency and early morning awakening.
L-Theanine (200mg with dinner) increases alpha brain wave activity — the relaxed-but-alert state. It synergizes with magnesium by calming the mind while magnesium relaxes muscles. Take with your last meal, not right before bed.
Ashwagandha KSM-66 (600mg morning) addresses the root cause for many: elevated cortisol. A 2019 study in Medicine showed KSM-66 reduced cortisol by 27.9% and improved sleep quality over 8 weeks. Morning dosing resets your cortisol rhythm — more effective than sedating yourself at night.
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Cognitive performance supplements have become the fastest-growing supplement category, but most products are underdosed or poorly timed. Here's what the evidence actually supports for sustainable mental energy.
Lion's Mane mushroom (500mg, morning with food) stimulates Nerve Growth Factor (NGF) production, supporting neuron growth and cognitive function. A 2009 Japanese double-blind trial showed significant improvements after 16 weeks. Effects are cumulative — expect 4–6 weeks before peak benefit.
Rhodiola Rosea (400mg, 30 min before demanding work) reduces mental fatigue by modulating the HPA axis. Unlike stimulants, it works on stress-induced brain fog. Take on an empty stomach; avoid combining with large amounts of caffeine.
B-Complex (with breakfast) provides cofactors for mitochondrial energy metabolism. Deficiencies in B12 and B9 are directly linked to brain fog and fatigue. Fat-soluble components improve absorption with food.
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Longevity supplementation has moved from biohacking into mainstream science, largely driven by Harvard's Sinclair lab and the NIA Interventions Testing Program. The core insight: aging is driven by declining NAD+ levels, mitochondrial dysfunction, and DNA damage accumulation — all partially addressable with targeted supplementation.
NMN (500mg, morning empty stomach) is the most direct NAD+ precursor. NAD+ declines ~50% between ages 40 and 60. NMN bypasses the rate-limiting step in NAD+ synthesis, restoring cellular energy metabolism and DNA repair. Food reduces absorption by up to 40%.
CoQ10 Ubiquinol (200mg, with fattiest meal) is essential for mitochondrial ATP production. After 40, conversion to the active ubiquinol form declines sharply. Ubiquinol has 3–4× better bioavailability than standard ubiquinone. Fat dramatically improves absorption.
Resveratrol (500mg, with lunch) activates SIRT1 — the longevity gene pathway. Its effect is amplified when combined with NMN, as both activate the SIRT1 pathway through different mechanisms. Best taken with a fat-containing meal.
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A free 60-second face scan estimates your biological age using AI-powered photoplethysmography — no wearable, no blood test, just your camera.
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