What a Plateau Actually Means

Nine in ten people in this analysis had reached a weight plateau by week 72.^[1] That sounds like weight loss stopping for almost everyone, and it is not what the number means — because of how the researchers defined a plateau, you can be counted as plateaued while still losing about 17% of your body weight a year.

The definition, which is in the methods

A participant was classified as having plateaued at the start of the first 12-week interval in which their weight changed by less than 5% — provided every subsequent 12-week interval also stayed under that threshold.

Losing 4% every twelve weeks counts as a plateau.

Four percent per quarter compounds to roughly 17% over a year. For someone starting at 100 kg that is around 15 kg in the year after they were declared to have plateaued. This is a threshold for the rate slowing, not a description of weight loss ending.

★ There is now a clean demonstration of exactly that. A separate systematic review asked the same question for a surgical purpose, defined a plateau as under 3% loss over at least a month, and arrived at 53 weeks rather than 24 to 36. Same phenomenon, stricter threshold, half a year of difference — when is it safe to have the skin removed.

When it happened

The pattern is orderly and worth knowing: the heavier someone started, the longer their rapid phase lasted — about six months for people in the overweight category against roughly eight and a half for the heaviest, a statistically significant difference. Results in the second trial were similar.

Three other factors pushed the plateau later: higher tirzepatide doses (10 or 15 mg), younger age, and being female. None of those is something to act on directly, and all of them are useful context for someone comparing their own curve to somebody else’s.

Who is in this analysis

That selection also means the plateau timings cannot be read as a forecast before starting. They are a description of what successful courses of treatment looked like in retrospect.

What to do with your own curve

The most common reason people conclude a drug has stopped working is that the scale moves less than it did in month two. Month two is the steepest part of a curve that flattens for everyone — comparing any later month against it will always look like failure.

• Expect the rapid phase to run roughly six to eight months, longer if you started heavier or are on a higher dose.
• Slowing is not stopping. Under this analysis’s own definition, a plateau is compatible with continuing to lose a substantial amount.
• The cardiovascular benefit does not track how fast you lose. In SELECT, protection appeared across every weight category with no relationship to early weight loss — losing weight predicted more heart attacks.
• Early response does carry information about the year ahead, which is a separate question — losing fast early.

One limitation on all of it: this is a post-hoc analysis, meaning the plateau question was asked of trial data collected to answer something else. The paper also carries a published correction to a figure in its own abstract, which is a small thing and worth knowing exists.