Limited · human
This pharmacovigilance study used the U.S. FDA Adverse Event Reporting System (FAERS) database (Q2 2022–Q2 2025) to examine whether specific GLP-1 receptor agonists (GLP-1 RAs) — exenatide, lixisenatide, liraglutide, dulaglutide, semaglutide, and tirzepatide — differ in their association with alopecia and reproductive or endocrine-related adverse events. Researchers identified 1,276 alopecia-related and 759 reproductive/endocrine-related cases, then applied disproportionality analyses using crude and adjusted reporting odds ratios (cROR/aROR) from logistic regression, controlling for potential confounders. Sensitivity analyses with positive and negative control drugs were used to validate signal robustness. The study found that semaglutide was significantly associated with disproportionate reporting of alopecia (aROR 1.23) and several hormonal conditions, including polycystic ovary syndrome (aROR 6.59) and menstrual abnormalities. By contrast, dulaglutide and tirzepatide showed negative or non-significant associations for several reproductive outcomes. Important limitations include the inherent biases of spontaneous reporting systems (e.g., underreporting, notoriety bias, inability to establish causation), lack of denominator data, and absence of clinical detail. The authors conclude that agent-specific differences in endocrine and dermatologic safety profiles may warrant personalised prescribing decisions and ongoing surveillance.
Diabetes/metabolism research and reviews · May 2026DOI ↗ Limited · human
This large-scale observational study used a federated biomedical data platform to analyze 135,349 individuals treated with GLP-1 receptor agonists (GLP-1RAs) — specifically semaglutide (Wegovy) and tirzepatide (Zepbound) formulations — to characterize differences between "super responders" (>15% weight loss), "moderate responders" (5–15% weight loss), and a "minimal weight-loss" group. The study found substantial heterogeneity in weight-loss outcomes across patients receiving the same therapies. Notably, super responders to Zepbound showed reduced risk of developing certain comorbidities, including conditions at relative risks as favorable as 0.5 for osteoarthritis (P = .001), while Wegovy super responders showed an association with psoriasis (RR = 2.5, P = .03). The authors conclude that differences in weight trajectories likely reflect a combination of biological, behavioral, and social factors. Key limitations include the observational, retrospective design (which cannot establish causation), the reliance on federated real-world data (subject to coding variability), and lack of randomization. The authors call for prospective studies to develop more individualized weight-loss strategies.
Biology methods & protocols · Apr 2026DOI ↗ Limited · human
This real-world observational study examined weight trajectories in 4,182 patients during the 6 months following their last documented semaglutide or tirzepatide prescription, drawn from a federated health network. The study found that approximately two-thirds of the full cohort showed stable weight or continued weight loss after their final prescription. In a representative subset of 300 patients whose clinical notes were analyzed using a large language model (LLM), treatment discontinuation was confirmed in 119 patients (40%), and of those, 72% did not demonstrate weight regain. The study also noted that exercise counseling was documented more frequently among patients who maintained weight loss compared to those who experienced weight regain (26.2% vs. 14.7%; P = .04). Key limitations include the observational and retrospective design, reliance on documented prescriptions rather than confirmed medication use, potential incompleteness of clinical records, use of an LLM for data curation introducing possible inaccuracies, and the inability to establish causation. The authors acknowledge that further studies are needed to understand the mechanisms behind these real-world patterns of weight maintenance after GLP-1 receptor agonist discontinuation.
Biology methods & protocols · Apr 2026DOI ↗ Limited · human
This review-style report examines the transfer of tirzepatide, a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist, into human breastmilk following subcutaneous administration. The paper notes that tirzepatide is generally undetectable in breastmilk at doses up to 5 mg, suggesting minimal maternal-to-infant transfer via lactation. The authors further reason that even if trace amounts were present, oral absorption by a nursing infant would likely be negligible, as the peptide is expected to undergo partial degradation in the infant's gastrointestinal tract and exhibits poor oral bioavailability. Based on these considerations, the paper concludes that maternal use of tirzepatide need not be an automatic reason to discontinue breastfeeding, while still recommending caution — particularly in the context of newborns or preterm infants, whose gastrointestinal and metabolic systems may differ from those of older infants. The report acknowledges that available data remain limited and calls for additional research before stronger conclusions can be drawn. Key limitations include the small body of evidence underpinning these conclusions and the absence of robust clinical trial data in lactating populations.
Unknown journal · Apr 2026Source ↗ Limited · human
This cross-sectional study conducted in Saudi Arabia (January–June 2025) investigated the frequency, characteristics, and predictors of hair loss among 254 adults using GLP-1 receptor agonists (GLP-1RAs) — specifically semaglutide (Ozempic), tirzepatide (Mounjaro), liraglutide (Saxenda), or liraglutide (Victoza) — primarily for weight loss. Data were collected via structured questionnaires covering demographics, clinical characteristics, and hair loss details such as timing, severity, and progression. The majority of participants were female (71.3%), with a mean age of approximately 33 years. The study found that overall hair loss prevalence did not differ significantly across GLP-1RA types (p = 0.116); however, severe hair loss was reported significantly more often among Mounjaro (43.4%) and Saxenda (42.9%) users. Female sex and Mounjaro use were identified as notable predictors of hair loss. The authors noted that the hair loss observed was generally non-scarring and potentially reversible, but associated with psychological distress and possible impacts on treatment adherence. Key limitations include the cross-sectional design (precluding causal inference), reliance on self-reported data, the single-country sample limiting generalizability, and the absence of a control group not using GLP-1RAs.
Journal of cosmetic dermatology · Apr 2026DOI ↗ Limited · human
This pharmacovigilance study compared post-marketing adverse event reporting patterns for tirzepatide (a dual GIP/GLP-1 receptor agonist) against semaglutide and liraglutide (GLP-1 receptor agonists) using aggregated Individual Case Safety Reports (ICSRs) from the EudraVigilance database. Researchers applied pairwise disproportionality analyses using reporting odds ratios (RORs) at the System Organ Class (SOC) level, with false discovery rate correction and sensitivity analyses limited to serious and healthcare professional-reported cases. The study found that, compared with semaglutide, tirzepatide was associated with higher relative reporting for immune system disorders (ROR 1.97) and hepatobiliary disorders (ROR 1.71). Compared with liraglutide, tirzepatide showed higher reporting for musculoskeletal (ROR 2.02) and psychiatric disorders (ROR 2.14), but lower reporting for neoplasms (ROR 0.28). Eight SOCs remained significant across all analytical conditions. The authors emphasize that these findings are hypothesis-generating only, as disproportionality analyses cannot establish causality, do not adjust for exposure levels, and are subject to reporting biases inherent in spontaneous pharmacovigilance databases. Confirmation in exposure-adjusted studies is recommended.
International journal of molecular sciences · Mar 2026DOI ↗ Limited · human
This study characterizes PG-102, a bispecific Fc fusion protein that co-activates both GLP-1 and GLP-2 receptors, combining preclinical animal work with a Phase I human trial. In db/db mice (a model of advanced type 2 diabetes with hyperglycemia and catabolic weight loss), PG-102 demonstrated superior and more sustained glycemic control compared to semaglutide or tirzepatide while preserving body weight — an effect attributed to β-cell preservation and enhanced glucose uptake rather than acute insulin stimulation. Mechanistic experiments suggested that dual receptor engagement was necessary for these benefits, with PG-102 also promoting coordinated, delayed receptor internalization compared to monospecific agents. The Phase I randomized, double-blind, placebo-controlled trial enrolled 24 adults with overweight (BMI 25–30 kg/m²) across three dose cohorts, with 18 receiving PG-102 and 6 receiving placebo. The primary endpoint was safety and tolerability. Treatment-emergent adverse events occurred in 83.3% of PG-102 participants and 66.7% of placebo participants; gastrointestinal events were mild to moderate. No serious adverse events or treatment discontinuations were reported. Limitations include the small sample size, single-center design, overweight-only population, and lack of efficacy endpoints in the human portion of the study.
Nature communications · Mar 2026DOI ↗ Limited · human
This pharmacovigilance study analyzed ocular adverse event (AE) reports associated with five GLP-1 receptor agonists (exenatide, tirzepatide, dulaglutide, liraglutide, and semaglutide) using the FDA Adverse Event Reporting System (FAERS) from 2005 to 2024. Ocular AEs comprised 3.61% of all GLP-1 RA-related reports; the median patient age was 63 years, and 62.6% of reports involved female patients. Disproportionality analysis using reporting odds ratios (RORs) identified a statistically significant signal for ocular AEs associated with semaglutide, while exenatide showed a significant annual decline in proportional reporting (-5.15% per year). The authors note that semaglutide's signal may partly reflect its growing market dominance rather than a true differential risk. Key limitations acknowledged by the study include the absence of exposure denominators and comparator groups, vulnerability of FAERS to reporting bias (including under- and over-reporting), and inability to establish causality. The authors characterize the findings as hypothesis-generating and recommend clinician vigilance regarding ocular monitoring, particularly in populations already at elevated risk for diabetic eye disease, while calling for further prospective research to validate these associations and explore potential mechanisms.
Journal of clinical medicine · Mar 2026DOI ↗ Limited · human
This qualitative, multi-method study explored how adults living with obesity make decisions about initiating pharmacotherapy. Researchers used three complementary methods — semi-structured interviews (n=15), a Photovoice study (n=12), and focus group discussions (n=12) — to purposively recruit adults aged 18–70 with a BMI ≥27 kg/m² and at least one obesity-related complication, all of whom were naïve to obesity medications. Through triangulation of findings across all three methods, the study identified five key factors shaping patient preferences: (1) anticipated treatment efficacy, (2) adequacy of information and community support, (3) safety and tolerability profile, (4) treatment burden and lifestyle integration, and (5) logistical and structural barriers. Tirzepatide was the most preferred agent across all methods, largely due to its perceived weight-reduction potential, while semaglutide ranked second, aided by its broader societal familiarity. Perceived efficacy and information trustworthiness emerged as the dominant drivers of preference, with safety concerns consistently moderating enthusiasm. The study is limited by its qualitative design, modest sample sizes, and the fact that all participants were medication-naïve, which may limit transferability to experienced patients. The authors recommend clinicians engage in shared decision-making tailored to individual information needs and social contexts.
Obesity pillars · Mar 2026DOI ↗ Limited · human
This retrospective, claims-based observational study examined real-world persistence, adherence, and weight-loss effectiveness of GLP-1 receptor agonists (semaglutide/Wegovy) and the dual GLP-1/GIP agonist (tirzepatide/Zepbound) among 7,493 adults enrolled in Massachusetts Medicaid (MassHealth) who initiated treatment between July and December 2024. At 6 months, the study found moderate rates of persistence (60.8%, defined as no gap greater than 56 days between fills) and adherence (60.1%, defined as proportion of days covered ≥80%). Male sex and younger age were among the member-specific factors associated with lower persistence and adherence. In a subgroup of highly persistent and adherent members with prior authorization recertification data, both tirzepatide and semaglutide were associated with at least 5% body weight reduction at 6 months. Key limitations include the retrospective claims-based design, which cannot establish causality, the restriction to a Medicaid population limiting generalizability, and the weight-loss outcome being measured only in a select, highly adherent subgroup rather than the full cohort.
Journal of managed care & specialty pharmacy · Mar 2026DOI ↗ Limited · human
This real-world pharmacovigilance study analyzed 40,253 adverse event reports submitted to the FDA Adverse Event Reporting System (FAERS) involving semaglutide, liraglutide, and tirzepatide used for weight loss. Researchers applied disproportionality analysis—using proportional reporting ratios (PRR) and reporting odds ratios (ROR)—to identify safety signals beyond the commonly studied gastrointestinal, renal, and pancreatic effects. The study population was predominantly female (68.6%), with median ages varying by drug. Key findings included that semaglutide showed the strongest disproportionality signals for psychiatric adverse events, including anxiety, depression, and suicidal ideation. Tirzepatide was associated with markedly elevated signals for injection-site reactions and indicators of misuse, such as incorrect dosing and off-label administration. Liraglutide showed a comparatively lower overall risk signal across these categories. Important limitations of this study include the inherent biases of spontaneous reporting systems (underreporting, confounding, lack of denominator data), the inability to establish causality, and the possibility that reporting patterns reflect prescribing trends or media attention rather than true pharmacological risk. The authors conclude that psychiatric monitoring and patient education warrant greater attention in clinical practice.
Pharmaceuticals (Basel, Switzerland) · Feb 2026DOI ↗ Limited · human
This retrospective pharmacovigilance study analyzed FDA Adverse Event Reporting System (FAERS) data from Q1 2022 to Q3 2025 to compare gynecological hemorrhagic event reporting between tirzepatide (a dual GIP/GLP-1 receptor agonist) and semaglutide (a GLP-1 receptor agonist) in female patients. Researchers identified 103,607 female-specific reports—70,768 for tirzepatide and 32,839 for semaglutide—and calculated reporting odds ratios (RORs) using standardized MedDRA queries. The study found that gynecological hemorrhagic events were reported at nearly identical rates (0.60% for tirzepatide vs. 0.62% for semaglutide), with an ROR of 0.97 (95% CI: 0.82–1.14), indicating no statistically significant difference in reporting odds between the two agents. Notably, the authors flagged a substantial difference in reporter source composition: 94.6% of tirzepatide reports originated from consumers versus 53.4% for semaglutide, which may introduce bias and limits direct comparability. The authors concluded that no disproportionate safety signal was detected but emphasized that disproportionality analyses cannot establish causation, and that the consumer-reporting imbalance warrants cautious interpretation. Prospective, controlled studies were recommended to validate these findings.
Limited · human
This case report describes a 61-year-old woman with type 2 diabetes and morbid obesity who developed severe small bowel obstruction after more than a year of tirzepatide therapy. The patient experienced progressive constipation following initiation of tirzepatide, eventually presenting with acute diffuse abdominal pain and dry heaving. CT imaging revealed multiple dilated, fluid-filled small bowel loops with a transition point in the lower pelvis, moderate gastric distention, and free pelvic fluid. Initial conservative management with nasogastric decompression, bowel rest, intravenous fluids, and analgesia was insufficient, and the patient ultimately required laparoscopic adhesiolysis converted to exploratory laparotomy. Intraoperatively, a closed-loop obstruction caused by adhesive disease and an internal hernia was identified, necessitating resection of 25 cm of necrotic bowel. Pathology confirmed ischemic changes. Notably, tirzepatide had produced meaningful metabolic benefits, including hemoglobin A1c reduction and weight loss. The authors propose that tirzepatide's known effects on gastrointestinal motility may have worsened pre-existing constipation and contributed to the obstructive event in this predisposed patient. Key limitations include the single-patient design, the presence of confounding adhesive disease, and the inability to establish direct causation.
Limited · human
This cross-sectional study examined self-reported outcomes among 486 adults in Kuwait who were using or had previously used GLP-1 receptor agonist (GLP-1 RA) injections — Semaglutide (n=181), Liraglutide (n=152), or Tirzepatide (n=132) — for weight loss, surveyed between February and May 2024. Participants completed an online questionnaire covering demographics, weight change, side effects, and quality of life. The study found that Tirzepatide users reported the highest average monthly and annual weight loss, along with the greatest satisfaction (88%) and most frequently reported improvements in quality of life (60%) compared to the other two agents. Side-effect profiles differed across groups: Tirzepatide users more commonly reported belching, while Liraglutide users reported higher rates of anxiety and were more likely to switch medications. No statistically significant differences were observed between groups in BMI, dietary adherence, or treatment compliance. Key limitations include the cross-sectional, self-report design, recruitment via online survey (introducing selection bias), lack of clinical verification of outcomes, and the inability to establish causality. The study also does not account for differences in duration of use, dosing, or baseline characteristics across groups.
Frontiers in nutrition · May 2025DOI ↗