SDAI BioAge Longevity
Your age is a date. Your biology is a measurement.
Estimate your biological age from eight inputs, then see exactly which of them is driving the number and how much of it you can move. Every weight in the model is published and sourced, including the ones that work against us.
There is no supplement input in this calculator. A tool that projects an age reduction from a product purchase would be inventing a number the research does not support.
What the research supports, in order
Most longevity content is arranged around what it is selling. This one is arranged by effect size, which puts the things you can do for free at the top and the thing we sell near the bottom.
- Tier 1
Tobacco, fitness, central adiposity
These three dominate. Together they account for most of the movement available on any biological age model, and nothing sold in a bottle competes with them.
- Tier 2
Sleep, resting heart rate, diet quality
Large, consistent and widely ignored. Each is worth roughly one to three years on most proxy models.
- Tier 3
Alcohol, chronic stress, social connection
Smaller effects, well evidenced, and cheap to act on.
- Tier 4
Supplementation, including AKG
An adjunct with early human evidence. Worth considering once the tiers above are handled. Not before.
Where alpha-ketoglutarate honestly sits
The mechanism is sound
AKG is a citric acid cycle intermediate and a required cofactor for the TET enzymes involved in DNA demethylation. Since epigenetic clocks read methylation, that is a sensible place to look. Circulating levels also decline with age.
The human data is thin
One retrospective analysis of 42 self-selected people with no control group, plus observational associations. Good animal data. No randomised controlled trial has reported biological age outcomes.
So we say so
Early-stage candidate, not a demonstrated intervention. Both halves of that sentence are true and most pages in this category only print one of them.
Measure, then decide
A standard blood panel from your doctor gives you real biomarkers for a fraction of the cost of a year of any supplement. Start there. If your numbers are already good and you want to spend on a marginal intervention with early evidence, that is a reasonable position to arrive at, and it should be arrived at in that order.
