(NewsNation) — Single women became significantly more likely to marry or move in with a partner after starting GLP-1 weight-loss medications, according to new research from a Harvard economist.

The June 2026 study, authored by Rebecca Diamond, the Martin Feldstein Professor of Economics, found that single women’s likelihood of marrying or cohabitating with a partner rose by as much as 28.6 percentage points after a year and a half on the drugs.

Unemployed women’s odds of landing a job climbed 26.9 percentage points over the same period.

The working paper, published by the National Bureau of Economic Research, compared women taking GLP-1 drugs to a control group of women who wanted to start the medications but had not yet done so.

“When you look at women before versus after taking these, how is their life changing?” Diamond said. “The thing that sort of jumps most strongly off the page is this increase in marriage and partnership.”

How the Harvard study measured GLP-1 effects on women

Diamond drew her data from the Understanding America Study, based at the University of Southern California, which surveys participants quarterly on GLP-1 use, employment, marital status, body-mass index, health and mood.

She limited her analysis to women because too few men in the sample were taking the drugs to yield reliable results.

Diamond said she began investigating the topic after a friend who had taken GLP-1 drugs described feeling treated differently once she lost weight.

“It was almost a passing comment, but it gave me the curiosity of, ‘Huh, is there any research on the economic and social implications of these drugs?’” Diamond said. “I did a quick lit review, and I couldn’t really find anything. Then I dug into it.”

The passing comment that sparked the research

The gains were concentrated among women forming new relationships or seeking new jobs — not those already partnered or employed. Women who were already married or employed before starting the drugs reported no meaningful change in those areas, and already-employed women saw no rise in hours or promotions.

Diamond said she tested whether the results could instead reflect improved mood or motivation after weight loss, but found little change in participants’ reported depression, loneliness or life satisfaction — not enough, she said, to account for the size of the marriage increase.

“There hasn’t been a great setting to disentangle weight from these other causal things,” Diamond said, noting that GLP-1 drugs offer researchers a rare natural experiment because they produce substantial weight loss within about a year.

“You might expect if you’re just more motivated and more excited about taking on new things, you might have seen some increase in those metrics. But we don’t see that. That’s why I think it’s more about the first impression margin.”

Diamond said the findings point to bias in early-stage judgments — hiring decisions and initial romantic attraction — rather than in established relationships or jobs, where people are better known.

“For people who have been in a job a long time, the employer knows whether you’re good at the job; they don’t care about your weight at that point anymore,” Diamond said. “On the partnership margin, your partner cares about more than just your weight; that’s why you are with them.”