# Sleep and Mood on a GLP-1: What Improved, and What Did Not Predict It

By Nora Bissett, Pricing Editor (https://glpwatchdog.org/authors/nora-bissett) | Published: 2026-08-21 | Updated: 2026-10-30

Canonical page: https://glpwatchdog.org/research/glp1-sleep-quality-and-mood

> In 78 people starting semaglutide or tirzepatide, poor sleep quality fell from 55.1% to 16.7% and clinically significant depressive symptoms from 55.1% to 11.5% over three months. Percentage weight loss was not significantly associated with either improvement.

## Key points

- Prospective observational study, 78 patients (52 tirzepatide, 26 semaglutide), baseline to month 3.
- Poor sleep quality (PSQI > 5) fell from 55.1% to 16.7%; PHQ-9 >= 10 fell from 55.1% to 11.5%.
- In multivariable models, percentage weight loss was not significantly associated with either response; sleep response tracked with improvement in depressive symptoms.
- No control group, and both medians began at or just over their thresholds, so regression to the mean cannot be excluded.

Seventy-eight people with obesity starting semaglutide or tirzepatide were assessed on two standard questionnaires at baseline and again at three months. The share scoring as poor sleepers fell from 55.1% to 16.7%, and the share with clinically significant depressive symptoms fell from 55.1% to 11.5%.[1] There was no control group, so the numbers support less than they seem to. One finding inside them stands out: the amount of weight lost was not what tracked with who improved.

## What was measured

A prospective observational study enrolled patients with obesity starting a GLP-1-based therapy: 52 on tirzepatide and 26 on semaglutide. Depressive symptom burden was measured with the PHQ-9 and sleep quality with the Pittsburgh Sleep Quality Index, at baseline and at month three.[1] Groups that size cannot say whether one drug is easier on mood than the other; [a study of more than 85,000 matched pairs](https://glpwatchdog.org/research/tirzepatide-versus-semaglutide-on-mood) found no difference.

*Baseline to three months, 78 patients, no control group.[1]*

|   | Baseline | Month 3 |
| --- | --- | --- |
| Median PHQ-9 (depressive symptoms) | 10.0 (7.0–14.0) | 6.0 (4.0–8.0) |
| Prevalence PHQ-9 ≥ 10 | 55.1% | **11.5%** |
| Median PSQI (sleep quality) | 6.0 (5.0–8.75) | 3.0 (2.0–4.0) |
| Prevalence PSQI > 5 (poor sleep) | 55.1% | **16.7%** |

> **No control group, and the baseline sits at or just over both thresholds.** Median PHQ-9 was 10.0 against a cut-off of 10, and median PSQI was 6.0 against a cut-off of 5. People are measured at the moment they seek treatment, which tends to be when things are worst; scores drift back toward the middle regardless of what is done. Regression to the mean is not excluded here, and with 78 uncontrolled patients it cannot be.

## The part that is not about weight

The intuitive story is that people lost weight, so they slept better and felt better. The multivariable models point elsewhere. What was associated with a depressive-symptom response was a higher baseline PHQ-9 and younger age. What was associated with a sleep response was a higher baseline PSQI and a greater improvement in depressive symptoms.[1]

Percentage weight loss did not emerge as the driver of either. Mood improvement tracked with sleep improvement, which is a well-known relationship in both directions and does not need the scale to explain it.

> Percentage weight loss was not significantly associated with either the sleep or the mood response.

Two cautions on reading that as good news. Higher baseline scores predicting more improvement is exactly what regression to the mean produces, so that particular association is the least surprising thing in the paper. And an uncontrolled study cannot separate a drug effect from the effect of starting a treatment you have hopes for.

## What it does not support

- No GLP-1 is approved for depression or for insomnia, and nothing here suggests taking one for either.
- Three months is short. Neither sleep nor mood was followed beyond that.
- 78 people without a control group cannot establish that the drug caused the change.
- If you are taking medication for depression or sleep, a GLP-1 is not a substitute and changes belong with your prescriber.
- Anyone whose mood worsens after starting one of these drugs should raise it promptly rather than wait. This study did not look for worsening.

For a randomized look at mood and cognition see [the semaglutide depression and cognition trial](https://glpwatchdog.org/research/semaglutide-depression-cognition-trial); for daytime sleepiness specifically, [GLP-1s and daytime sleepiness](https://glpwatchdog.org/research/glp1s-and-daytime-sleepiness); and for the airway condition with an approved indication, [Zepbound for sleep apnea](https://glpwatchdog.org/research/zepbound-for-sleep-apnea). If the question is vivid dreams or nightmares, see [what is known about GLP-1s and dreams](https://glpwatchdog.org/research/glp1-vivid-dreams-and-nightmares).

## Frequently asked questions

### Do GLP-1 drugs improve sleep?

In a prospective study of 78 people starting semaglutide or tirzepatide, the proportion scoring as poor sleepers on the Pittsburgh Sleep Quality Index fell from 55.1% to 16.7% over three months. There was no control group, so the change cannot be attributed to the drug.

### Is that just because of the weight loss?

Apparently not, at least in these models. Percentage weight loss was not what tracked with response. Sleep improvement was associated with higher baseline sleep scores and with improvement in depressive symptoms instead.

### Did depression scores improve?

Median PHQ-9 fell from 10.0 to 6.0, and the share with clinically significant depressive symptoms fell from 55.1% to 11.5%. The same caveat applies: no control group, three months, 78 people.

### Should I take a GLP-1 for insomnia or low mood?

No. Neither is an approved indication and this evidence cannot support it. If you take medication for depression or sleep, a GLP-1 is not a substitute, and any change belongs with your prescriber.

## References

1. Kır Y, Haymana C, Toros B, et al. Prospective changes in sleep quality and depressive symptom burden following initiation of GLP-1-based therapies in patients with obesity: a real-world study. Journal of Endocrinological Investigation. 2026. PMID: 42611111. https://pubmed.ncbi.nlm.nih.gov/42611111/

---

Cite as: GLP Watchdog, Nora Bissett, "Sleep and Mood on a GLP-1: What Improved, and What Did Not Predict It", published 2026-08-21, updated 2026-10-30. https://glpwatchdog.org/research/glp1-sleep-quality-and-mood

Canonical HTML page: https://glpwatchdog.org/research/glp1-sleep-quality-and-mood

Medical disclaimer: Nothing here is medical advice. We report on this subject; we do not treat anyone. Whether to begin a medication, supplement, or treatment, whether to adjust it, and whether to stop are questions for a clinician licensed to answer them, who knows your history.