Across those 42 people, peak BrAC (breath alcohol concentration) ranged from 0.040 to 0.117 g/210L - nearly a 3x spread from lowest to highest. The timing surprised me more. Most peaked within 13 minutes of stopping. Some were still climbing more than an hour after their last drink, and a few had already peaked before they finished the final glass.

How it ran

42 adults, one supervised social drinking session. Everyone picked their own 80-proof mixed drinks - no fixed dose, no standardized schedule. Food sat on the table throughout and people ate as they liked. Sessions ran 45 to 172 minutes (mean 108, median 110), so some were still going when others had been done for over an hour. BrAC was measured about every 30 minutes with a calibrated breathalyzer until each participant returned to zero.

Messy by design. Most controlled alcohol studies fix the dose and cut out food to maximize pharmacokinetic precision. This one let those constraints go, to see what variability looks like in something closer to an actual night out.

The spread

The variation showed up in every measure:

  • Peak BrAC: 0.040 to 0.117 g/210L, mean 0.087. More than 2.5x between the lowest and the highest person.
  • Time from last drink to peak ran from -23 to 76 minutes (mean 17, median 13). That's the stranger number. Most crested within 13 minutes of stopping; some kept climbing over an hour later. The negatives - a peak arriving before the final drink - aren't explained mechanistically in the abstract, though they probably reflect someone easing off sharply late in the session.
  • Elimination averaged 0.0186 g/210L/hr, from 0.0134 to 0.0261. Nearly double between the fastest and the slowest person.
  • A few showed multi-peak absorption: BrAC rose, dipped, climbed again, then came down for good. Once elimination started, it ran linear.

Where averages break down

The limits first. Participants chose their own drinks and ate freely, so part of the peak spread is just dose - drink more, peak higher. Food intake wasn't quantified, and food slows absorption sharply. 42 people, each measured once. Nothing here says how reproducible one person's profile is from night to night.

The timing is harder to wave off. A 76-minute post-drink peak is a 76-minute peak whatever the dose was. So is the elimination range, 0.0134 to 0.0261 g/210L/hr - nearly 2x between people. Both point to real individual variation in how alcohol moves through the body.

Which sits a long way from what a generic alcohol calculator assumes about you: average metabolizer, average night. Two people can feed it identical inputs - weight, sex, drinks consumed, time elapsed - and clear alcohol at rates that differ by nearly 2x. One of them peaks 76 minutes after stopping. The formula has no way to know which one you are.

On a night you ate late, drank slowly, or just happen to clear alcohol slowly, the gap between a formula and your actual curve gets wide. And wide in the wrong direction: you think you've peaked, and you're still climbing.

That gap is what AlcoBalance is built around. Instead of a generic estimate, it tracks your actual curve - when your peak hits, when it fades. On a night your pace crept up without you noticing, you can see where you actually are on that curve and ease off while you're still steering the evening.

Source: Journal of Analytical Toxicology, DOI