Retatrutide, Sleep, Emotional Flatness and Anhedonia: What Community Reports Describe and What the Evidence Base Actually Contains

Our existing retatrutide articles cover the trial side-effect tables, heart rate, HRV and fatigue, the time course of effects, TRIUMPH-1, EU approval status and the buy article. This article covers three things community posters describe that appear in no retatrutide trial table: disturbed sleep, emotional flatness or anhedonia, and low mood or irritability, set next to the retatrutide publications, the approved GLP-1-class labels and regulators, pharmacovigilance and cohort studies, and the reward-system literature's mechanism hypothesis, together with the confounders that make a self-report uninterpretable. It contains no dosing, timing or treatment advice, and, as the notice below states, no claim that retatrutide causes or does not cause them.

Retatrutidemetabolic

First-ever triple-action weight management peptide targeting three receptors at once: GLP-1, GIP, and glucagon. Shown exceptional results in Phase 2 trials - up to 24% weight reduction. The most advanced metabolic peptide available.

Tirzepatidemetabolic

A first-in-class dual GIP and GLP-1 receptor agonist, and one of the most extensively studied compounds in modern metabolic and weight-regulation research. Supplied as a lyophilised research peptide with a per-batch certificate of analysis, for laboratory and in-vitro use only.

Metabolic Researchmetabolic

GIP/GLP-1/Glucagon agonists and metabolic pathways

What people are describing

Our Reddit corpus, the 12 months to August 2026, is a community report, not a scientific sample. Of 32,408 posts mentioning retatrutide, 981 use strict, explicit language for disturbed sleep, emotional flatness or anhedonia, or low mood (table below); the three clusters overlap, so the sleep, flatness and low-mood counts do not sum cleanly to 981. Only 4 posts mention both insomnia and anhedonia in the same post, a small overlap given the size of each group, and 859 of the 981 sit in r/Retatrutide, with 51 in r/Biohackers, 45 in r/Peptides and 18 in r/PeptideDiscussion. YouTube content was not reviewed.

The monthly count of these 981 posts rose across the period: 31 in September 2025, 105 in March 2026, 142 in May 2026 and 158 in July 2026. Monthly denominators for the subreddit are not available in the corpus, so the rise cannot be read as a change in how often the experience occurs.

Within the 277 flatness or anhedonia posts, framing splits unevenly: 97 use negative language (zombie, numb, miserable, quitting) against 19 positive (calmer, freedom, "a plus"); 28 mention alcohol or drinking, 24 mention porn, gaming, social media or other "vices," and 52 mention lowering the dose, cycling off or stopping, without specifying how. Within the 346 sleep posts, 64 describe feeling wired, on edge, in "fight or flight" or a racing heart; 49 tie the onset to the first weeks or a dose increase; 14 mention a dosing time; and 17 report improved sleep. Across the full 981, 68 describe the effect resolving or changing after lowering the dose or stopping, by self-report only, without verification.

A handful of threads illustrate the pattern, cited by title only, with no links or usernames. "The anhedonia is making me want to stay on reta forever" (204 upvotes): a poster with lifelong anxiety describes caring less as a relief, with less social-media use. "Reta making me not care about ANYTHING" (142 upvotes, 113 comments): lost interest in almost everything, including the gym; the poster says many others report the same. "Anhedonia??" (124 upvotes, 101 comments): a partner describes a husband going, in the poster's words, "from a 4 to a 0" within six weeks. "Anhedonia/Depression goes away when cycling off RETA" (113 upvotes, 81 comments): zest, libido, hobbies and humor returned after stopping, and every GLP-1-class compound tried had produced the same "robot" feeling. "Lowered my dose and this happened" (391 upvotes, 185 comments): mild depression, fatigue and flatness on the compound, lifting after tapering, alongside a year without former vices. "I prefer being overweight" (100 upvotes, 119 comments): joy and sex drive gone after six months, now stopping. "Retatrutide is a goat? Yes. Will I ever use it again? Never." (96 upvotes, 107 comments): "not exactly sadness, not exactly depression, just nothing." "Everything I wish someone told me before starting Reta, an honest 6-month breakdown" (173 upvotes): "a weird emotional flatness" around month four, after food had been the poster's comfort. "Reta & alcohol tolerance (a PSA)" (318 upvotes, 138 comments): no desire or pleasure from drinking, and lower tolerance. "Hot take: Tirzepatide is superior to Reta" (246 upvotes, 221 comments): "wired," a "low-grade fight-or-flight mode," and sleep issues. "My sleep is destroyed" (52 upvotes, 100 comments): about four hours of sleep a night one month in, otherwise pleased with the compound. "Reta side effects after 4 months of usage" (109 upvotes, 179 comments): slight sleep disruption tied by the poster to injecting late in the day, settling by month three.

The pattern across these threads is consistent: single accounts, several changes happening at once (a large energy deficit, weight loss, reduced alcohol, sometimes other compounds such as TRT or GH secretagogues, sometimes pre-existing anxiety, binge eating or trauma disclosed by the poster), no instrument, no control group, unverified product identity, and both welcomed and unwelcome versions of the same underlying experience.

What the retatrutide publications contain

No retatrutide trial published to date lists sleep disturbance, insomnia, mood, depression, anxiety or anhedonia as a measured outcome. A PubMed search for retatrutide combined with any of these terms, run in August 2026, found no retatrutide study reporting them.

The phase 2 obesity trial (Jastreboff and colleagues, NEJM 2023, PMID 37366315), 48 weeks, found a mean weight change of -24.2% at the 12 mg dose against -2.1% with placebo, and states that "the most common adverse events in the retatrutide groups were gastrointestinal; these events were dose-related, were mostly mild to moderate in severity," with "dose-dependent increases in heart rate peaked at 24 weeks and declined thereafter." The 40-week phase 3 diabetes trial TRANSCEND-T2D-1 (Bajaj and colleagues, Lancet 2026, PMID 42250575) reports similarly mild-to-moderate, subsiding gastrointestinal events, discontinuations of 2% to 5% against 0% on placebo, and "an adverse event profile consistent with molecules with GLP-1 agonist activity." Sleep, mood and anhedonia are absent from both papers' outcomes entirely, not reported as null findings.

The TRIUMPH design paper (Giblin and colleagues, Diabetes Obes Metab 2026, PMID 41090431) describes four phase 3 trials enrolling over 5,800 participants, including an obstructive sleep apnea basket with the apnea-hypopnea index as its primary endpoint. This is retatrutide being studied for a sleep-related disorder, not as a cause of sleep disturbance: the program's other primary endpoints are weight change and the WOMAC pain score, and whether mood or anhedonia instruments appear anywhere in the program is not stated in the abstract.

Retatrutide currently carries no marketing authorization and therefore has no product label (see our regulatory status article), so the next section turns to the approved GLP-1-class agents instead.

What the approved class labels and the regulators say

Retatrutide has no label of its own, so this section reviews the closest available evidence: the approved GLP-1-class agents, which share GLP-1 receptor agonism with retatrutide but not its added glucagon-receptor agonism. Everything below is class evidence, not retatrutide evidence.

In a Drug Safety Communication dated January 13, 2026, the FDA reported that after reviewing 91 placebo-controlled GLP-1 medication trials covering 107,910 patients (60,338 on a GLP-1 medication, 47,572 on placebo), "the results did not demonstrate an increased risk of suicidal behavior or ideation." On the strength of that review, the FDA requested removal of the suicidal-behavior-and-ideation warning from semaglutide, tirzepatide and liraglutide labels, while stating that health care professionals should continue to refer individuals who report suicidal ideation or behavior to mental health professionals.

WEGOVY's and ZEPBOUND's current US labels both carry the removal note shown in the table above; their adverse-reaction tables report the fatigue, headache, dizziness and dysesthesia rates shown there, the WEGOVY adult table has no insomnia row, and the ZEPBOUND tables list no insomnia, sleep-disorder, depression or anxiety rows at all.

The EMA's Pharmacovigilance Risk Assessment Committee reached a comparable conclusion in April 2024, stating that "the available evidence does not support a causal association between the Glucagon-Like Peptide-1 receptor agonists (GLP-1) - dulaglutide, exenatide, liraglutide, lixisenatide and semaglutide - and suicidal and self-injurious thoughts and actions," while noting that marketing authorization holders would continue to monitor these events in their periodic safety reports.

Both statements are regulator conclusions about the approved GLP-1 class: semaglutide, tirzepatide, liraglutide, dulaglutide, exenatide and lixisenatide. Retatrutide adds glucagon-receptor agonism to the same GLP-1 mechanism and sits outside both conclusions, which cover only the approved agents; it has no marketing authorization and no label. This class evidence is the closest available comparison, not evidence about retatrutide itself.

Pharmacovigilance and cohort studies: signals, not causes

Beyond the suicidality question the labels now answer, a separate body of pharmacovigilance and cohort research has looked at depression and mood across the GLP-1 class (table below). All of it is class-level; none of it is retatrutide data, and none of it measured anhedonia, emotional flatness or sleep.

The four pharmacovigilance studies each add a caution the raw numbers alone do not convey. McIntyre and colleagues' 2024 FAERS analysis (PMID 38087976), applying Bradford Hill criteria against the available confounders, concluded that "no causal link between GLP-1 RAs and suicidality exists." Their 2025 VigiBase replication (PMID 39433133) writes plainly that "causation ... cannot be ascertained from ROR data." Wang and colleagues' 2025 FAERS-and-VigiBase study (PMID 40777864) describes its semaglutide-specific depression signal as following "an early failure pattern," clustering early in treatment, with more disproportionality among women. Lu and colleagues' 2025 FAERS analysis (PMID 39901452) calls its own work an "exploratory study" whose "findings require confirmation."

The cohort findings point in different directions depending on the comparator, and the authors' own words carry the same caution. The TriNetX study (Wang, Volkow and colleagues, Nature Medicine 2024, PMID 38182782) concludes that "our findings do not support higher risks of suicidal ideation with semaglutide." The Medicare target-trial emulation (Tang and colleagues, Annals of Internal Medicine 2025, PMID 39993315) notes "limited generalizability ... to younger populations or those without T2D receiving the drug for obesity treatment" alongside unmeasured confounders. The six-health-system cohort study (Hooker and colleagues, Diabetes Obes Metab 2026, PMID 41479367) describes its own findings as "small, increased risks." The 2025 systematic review and meta-analysis (Bushi and colleagues, PMID 39945396) found substantial heterogeneity in its pooled estimate and concluded "no significant link between GLP-1RA use and increased suicidal ideation or behaviour," citing "high heterogeneity and reliance on pharmacovigilance data" as reasons for caution.

Two framing points hold across everything in this section. First, disproportionality is a reporting signal: a term appears more often in reports for one drug than expected, not proof the drug caused it, and every disproportionality study above says so directly. Second, the cohort studies disagree with each other because they compare against different things: GLP-1-class agents look favorable against non-GLP-1 anti-obesity drugs and, in one cohort, against DPP-4 inhibitors, while another cohort found no difference against DPP-4 inhibitors and small increases against SGLT2 inhibitors and sulfonylureas. None of the eight studies in this section measured anhedonia, emotional flatness or sleep, and none of them is retatrutide data.

The reward system: why flatness has a mechanism hypothesis

A class-level reward-system hypothesis may be relevant to the community's flatness and anhedonia reports, but it has not been shown to explain them, and the researchers who describe it frame it as therapeutic potential rather than an adverse effect.

A 2024 systematic review of human studies (Badulescu and colleagues, Physiol Behav, PMID 38945189) found that GLP-1 receptor agonists "consistently reduced energy intake and influenced reward-related behaviour," and were associated with "decreased neurocortical activation in response to higher rewards and food cues, particularly high-calorie foods." The authors write that these agents "might also modulate dopaminergic signalling and reduce anhedonia," discussing potential applications in addiction disorders. The review frames a reduced reward response as therapeutic potential, not an adverse event: it is the authors' hypothesis about a mechanism, not a demonstrated explanation for the community's reports. The same mechanism, a blunted reward response, is consistent with both a poster welcoming quieter cravings and a poster describing losing interest in everything they used to enjoy.

A 2025 systematic review of 26 studies and 3,020 participants (Meshkat and colleagues, Brain Behav, PMID 40635383) found mixed results: liraglutide at 1.8 mg per day improved depression and anhedonia scores in mood-disorder populations in one line of evidence, but of 9 randomized controlled trials in the review, only 3 reported a significant effect on the primary psychiatric outcome and 6 did not, effects the authors summarize as "mixed and inconclusive."

A 9-week phase 2 randomized controlled trial in adults with alcohol use disorder (Hendershot and colleagues, JAMA Psychiatry 2025, PMID 39937469) found low-dose semaglutide reduced drinks per drinking day (beta -0.41, 95% CI -0.73 to -0.09, P = .04), weekly alcohol craving (beta -0.39, 95% CI -0.73 to -0.06, P = .01), and grams of alcohol consumed in a laboratory self-administration task (beta -0.48, 95% CI -0.85 to -0.11, P = .01), without affecting average drinks per calendar day or the number of drinking days. The community's own alcohol thread ("Reta & alcohol tolerance (a PSA)," cited above) describes the same direction: no desire and no pleasure from drinking. That parallel is consistent with a reward-system effect; it is not proof: the trial tested semaglutide, not retatrutide, in a different population with a diagnosed condition.

Sleep: what exists and what does not

No retatrutide publication reports insomnia or sleep quality as a study outcome (the August 2026 PubMed search cited earlier found nothing). The one retatrutide finding that plausibly connects to the community's "wired" reports is the phase 2 trial's heart-rate result, a dose-dependent increase that peaked at 24 weeks and declined afterward: a hypothesis, not a tested one, covered in more depth in our dedicated article on heart rate, HRV and fatigue rather than re-explained here.

Where retatrutide trials touch sleep, they study it as a condition to treat, not a side effect to avoid. The TRIUMPH program includes an obstructive sleep apnea basket with the apnea-hypopnea index as its primary endpoint, following the same logic as tirzepatide's SURMOUNT-OSA trials (Malhotra and colleagues, NEJM 2024, PMID 38912654): two 52-week phase 3 trials found an AHI treatment difference of -20.0 events per hour and -23.8 events per hour (both p < 0.001), with "improved sleep-related patient-reported outcomes." A 2025 meta-analysis of 6 studies and 1,067 participants (Li and colleagues, Sleep, PMID 39626095) found an AHI treatment difference of -9.48 events per hour (95% CI -12.56 to -6.40, I2 = 92%) across the GLP-1 class, tirzepatide's effect (-21.86) larger than liraglutide's (-5.10). These trials measure a breathing disorder, obstructive sleep apnea, through the apnea-hypopnea index and sleep-related patient-reported outcomes; they do not study insomnia, and say nothing about the wired, cannot-sleep reports in the community corpus.

Two social-media studies found the same cluster of terms recurring. A mixed-methods study across Reddit, YouTube (14,515 videos) and TikTok (17,059 videos) (Arillotta and colleagues, Brain Sci 2023, PMID 38002464) found that "most represented matches related to sleep-related issues, including insomnia (n = 620 matches); anxiety (n = 353); depression (n = 204)," and that after starting GLP-1 receptor agonists, weight loss "was associated with either a marked improvement or, in some cases, a deterioration, in mood; increase/decrease in anxiety/insomnia; and better control of a range of addictive behaviors," a pattern the authors call hard to attribute cause and effect to. A 2025 study of 59,293 Facebook posts from 2022 to 2024 (Alibilli and colleagues, JMIR Infodemiology, PMID 40706081) found that among neurological symptoms, "anxiety, depression, and insomnia, were highly correlated with each other (50 to 100 co-occurrence mentions)," and the authors call for validation rather than presenting it as confirmed.

One further study offers context on the energy-deficit question without studying a GLP-1-class agent. CALERIE 2 (Martin and colleagues, JAMA Intern Med 2016, PMID 27136347) randomized 218 healthy nonobese adults to 25% calorie restriction or an ad libitum diet for 2 years; the restriction group lost 7.6 kg and showed improved mood (a between-group difference of -0.76 on the BDI-II), reduced tension, and improved sleep duration at month 12, with greater weight loss correlating with better sleep quality and less mood disturbance. In this healthier, smaller-deficit population, restriction did not worsen mood or sleep, which neither explains nor excludes the community's reports, since population and deficit size differ: it shows only that "the deficit alone" is not sufficient in that group.

Why a Reddit thread cannot answer the question

Every confounder listed below sits inside the same threads quoted in this article, and none can be separated from a single self-report. Weight loss itself carries social and psychological effects independent of any compound; removing food as a comfort behavior changes daily emotional experience, as one thread describes directly; reduced alcohol intake changes mood and sleep on its own, independent of any reward-system effect. Concurrent compounds, named in some threads as TRT, GH secretagogues or MOTS-c, sit alongside a large energy deficit in the same accounts, and pre-existing anxiety, binge eating or trauma history is disclosed in several of the threads quoted above. Time course varies within the corpus itself: flatness was reported around month four in one account, while sleep complaints cluster in the first weeks or after a dose increase in 49 of the 346 sleep posts. Product identity cannot be verified in a Reddit report (CoA verification is covered in our buying guide), reading the same threads before posting introduces an expectancy effect, and the corpus itself is selected toward people with a striking experience, welcomed or not, over people who noticed nothing. None of these can be isolated inside a Reddit thread, which is why the sections above turn to trial data, class labels, pharmacovigilance and cohort studies instead.

What a real answer would need

A real answer would require prespecified patient-reported outcomes in retatrutide's own phase 3 trials, using validated instruments: a sleep instrument such as the Pittsburgh Sleep Quality Index or the Insomnia Severity Index, an anhedonia scale such as SHAPS, and a depression scale such as PHQ-9, reported by dose and by time against placebo. The published TRIUMPH design paper lists weight, the apnea-hypopnea index and the WOMAC pain score as primary endpoints, with sleep-related patient-reported outcomes confined to the obstructive sleep apnea basket; whether mood or anhedonia instruments appear anywhere else in the program is not stated in the design paper's abstract, and this article does not speculate beyond that. Pharmacovigilance for retatrutide specifically, the FAERS- and VigiBase-style disproportionality analyses reviewed above for the approved class, will only become possible once retatrutide has a marketing authorization to generate spontaneous reports against. Until either exists, the honest position is the one this article has taken throughout: the community's 981 posts are real reports, and the retatrutide trial literature is silent on the outcomes they describe; neither fact resolves the other.

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Frequently asked questions

Sources

1. Jastreboff AM, Kaplan LM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial. N Engl J Med. 2023;389:514-526. PMID 37366315. https://pubmed.ncbi.nlm.nih.gov/37366315/
2. Bajaj HS, Welch M, et al. Efficacy and safety of retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial. Lancet. 2026;407:2402-2413. PMID 42250575. https://pubmed.ncbi.nlm.nih.gov/42250575/
3. Giblin K, Kaplan LM, et al. Retatrutide for the treatment of obesity, obstructive sleep apnea and knee osteoarthritis: Rationale and design of the TRIUMPH registrational clinical trials. Diabetes Obes Metab. 2026;28:83-93. PMID 41090431. https://pubmed.ncbi.nlm.nih.gov/41090431/
4. US Food and Drug Administration. Drug Safety Communication: FDA requests removal of suicidal behavior and ideation warning from glucagon-like peptide-1 receptor agonist (GLP-1 RA) medications. January 13, 2026. https://www.fda.gov/drugs/drug-safety-communications/fda-requests-removal-suicidal-behavior-and-ideation-warning-glucagon-peptide-1-receptor-agonist-glp
5. European Medicines Agency. Meeting highlights from the Pharmacovigilance Risk Assessment Committee (PRAC) 8-11 April 2024. https://www.ema.europa.eu/en/news/meeting-highlights-pharmacovigilance-risk-assessment-committee-prac-8-11-april-2024
6. Novo Nordisk. WEGOVY (semaglutide) prescribing information, revised 6/2026. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ee06186f-2aa3-4990-a760-757579d8f77b
7. Eli Lilly. ZEPBOUND (tirzepatide) prescribing information, revised 4/2026. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=487cd7e7-434c-4925-99fa-aa80b1cc776b
8. McIntyre RS, Mansur RB, et al. The association between glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and suicidality: reports to the Food and Drug Administration Adverse Event Reporting System (FAERS). Expert Opin Drug Saf. 2024;23:47-55. PMID 38087976. https://pubmed.ncbi.nlm.nih.gov/38087976/
9. McIntyre RS, Mansur RB, et al. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and suicidality: A replication study using reports to the World Health Organization pharmacovigilance database (VigiBase). J Affect Disord. 2025;369:922-927. PMID 39433133. https://pubmed.ncbi.nlm.nih.gov/39433133/
10. Wang M, Chen X, et al. Exploring potential associations between GLP-1RAs and depressive disorders: a pharmacovigilance study based on FAERS and VigiBase data. EClinicalMedicine. 2025;86:103385. PMID 40777864. https://pubmed.ncbi.nlm.nih.gov/40777864/
11. Lu W, Wang S, et al. Neuropsychiatric adverse events associated with Glucagon-like peptide-1 receptor agonists: a pharmacovigilance analysis of the FDA Adverse Event Reporting System database. Eur Psychiatry. 2025;68:e20. PMID 39901452. https://pubmed.ncbi.nlm.nih.gov/39901452/
12. Wang W, Volkow ND, et al. Association of semaglutide with risk of suicidal ideation in a real-world cohort. Nat Med. 2024;30:168-176. PMID 38182782. https://pubmed.ncbi.nlm.nih.gov/38182782/
13. Tang H, Lu Y, et al. Glucagon-Like Peptide-1 Receptor Agonists and Risk for Depression in Older Adults With Type 2 Diabetes: A Target Trial Emulation Study. Ann Intern Med. 2025;178:315-326. PMID 39993315. https://pubmed.ncbi.nlm.nih.gov/39993315/
14. Hooker SA, Neugebauer RS, et al. Comparative safety of glucose-lowering medications on depression in adults with type 2 diabetes. Diabetes Obes Metab. 2026;28:2215-2226. PMID 41479367. https://pubmed.ncbi.nlm.nih.gov/41479367/
15. Bushi G, Khatib MN, et al. Association of GLP-1 Receptor Agonists With Risk of Suicidal Ideation and Behaviour: A Systematic Review and Meta-Analysis. Diabetes Metab Res Rev. 2025;41:e70037. PMID 39945396. https://pubmed.ncbi.nlm.nih.gov/39945396/
16. Badulescu S, Tabassum A, et al. Glucagon-like peptide 1 agonist and effects on reward behaviour: A systematic review. Physiol Behav. 2024;283:114622. PMID 38945189. https://pubmed.ncbi.nlm.nih.gov/38945189/
17. Meshkat S, Di Luciano C, et al. Efficacy and Safety of Glucagon-Like Peptide-1 Agonists for Psychiatric Symptoms: A Systematic Review. Brain Behav. 2025;15:e70661. PMID 40635383. https://pubmed.ncbi.nlm.nih.gov/40635383/
18. Hendershot CS, Bremmer MP, et al. Once-Weekly Semaglutide in Adults With Alcohol Use Disorder: A Randomized Clinical Trial. JAMA Psychiatry. 2025;82:395-405. PMID 39937469. https://pubmed.ncbi.nlm.nih.gov/39937469/
19. Malhotra A, Grunstein RR, et al. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity. N Engl J Med. 2024;391:1193-1205. PMID 38912654. https://pubmed.ncbi.nlm.nih.gov/38912654/
20. Li M, Lin H, et al. Glucagon-like peptide-1 receptor agonists for the treatment of obstructive sleep apnea: a meta-analysis. Sleep. 2025;48. PMID 39626095. https://pubmed.ncbi.nlm.nih.gov/39626095/
21. Arillotta D, Floresta G, et al. GLP-1 Receptor Agonists and Related Mental Health Issues; Insights from a Range of Social Media Platforms Using a Mixed-Methods Approach. Brain Sci. 2023;13:1503. PMID 38002464. https://pubmed.ncbi.nlm.nih.gov/38002464/
22. Alibilli AS, Jain V, et al. Harnessing Facebook to Investigate Real-World Mentions of Adverse Events of Glucagon-Like Peptide-1 Receptor Agonist (GLP-1 RA) Medications: Observational Study of Facebook Posts From 2022 to 2024. JMIR Infodemiology. 2025;5:e73619. PMID 40706081. https://pubmed.ncbi.nlm.nih.gov/40706081/
23. Martin CK, Bhapkar M, et al. Effect of Calorie Restriction on Mood, Quality of Life, Sleep, and Sexual Function in Healthy Nonobese Adults: The CALERIE 2 Randomized Clinical Trial. JAMA Intern Med. 2016;176:743-52. PMID 27136347. https://pubmed.ncbi.nlm.nih.gov/27136347/
24. Reddit corpus extraction, 12 months to August 2026 (our own count: 32,408 retatrutide posts, 981 with explicit sleep, flatness/anhedonia or low-mood language); threads cited by title, not linked; YouTube content not reviewed.
25. PubMed search, August 2026: retatrutide combined with insomnia, sleep, mood, depression, anxiety or anhedonia: no retatrutide study with these outcomes.

Research use only. Retatrutide is supplied for laboratory research, not for human or animal administration, and not as a medicine. Nothing in this article is a dosing, protocol, or treatment instruction, and nothing here claims that retatrutide causes, or does not cause, insomnia, emotional flatness, anhedonia or low mood.