Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are increasingly used for metabolic disorders, including type 2 diabetes mellitus (T2DM) and obesity. Reports to date have documented hair loss as an adverse event, while cases of hair regrowth have also been described [1]. This review evaluates evidence linking GLP-1RA use to hair outcomes. Following PRISMA guidelines, Embase and MEDLINE were searched (from inception to July 2025) using keywords specific to GLP-1RAs, “alopecia,” and “hair regrowth” (PROSPERO: CRD420251104356). Of 485 records identified, 10 full-text studies were included, comprising three retrospective cohort studies, four retrospective pharmacovigilance database studies, one living benefit-harm modeling study, one case–control study, and one case report. Risk of bias was assessed using Joanna Briggs critical appraisal tools. Hair loss type was mostly unspecified; however, 82 patients had centrifugal cicatricial alopecia (CCCA), 20 had androgenic alopecia (AGA), and 10 had telogen effluvium. Pharmacovigilance and modeling analyses examined a total of 920,890 adverse events, while cohort studies involved 382 patients. GLP-1RAs investigated included exenatide (27.1%, 170,880/630,671), dulaglutide (23.4%, 147,624/630,671), liraglutide (21.4%, 135,178/630,671), semaglutide (11.3%, 71,528/630,671), and tirzepatide (9.9%, 62,196/630,671). Of 626,894 patients on GLP-1RA for whom hair outcomes were reported, 9933 (1.6%) experienced hair loss, whereas 52 (0.008%) reported hair regrowth. Latency to hair loss or gender differences in alopecia events were not well described in studies. Clinical outcomes are summarized in Table 1. Multiple pharmacovigilance analysis studies identified a weak association between GLP-1RA use and hair loss, most commonly with semaglutide (reporting odds ratio (ROR), 1.24–2.46), followed by tirzepatide (ROR, 0.83–1.73) and liraglutide (ROR, 0.61–1.53). One disproportionality analysis of the US Food and Drug Administration's Adverse Event Reporting System (FAERS) (2022–2023 exclusively) revealed a positive signal for alopecia with semaglutide (ROR, 2.46) and tirzepatide (ROR, 1.73), suggesting that rates may exceed background reporting levels [2]. A review of several pharmacovigilance databases (FAERS, Vigibase, Eudravigilance, Database of Adverse Event Notifications (DAEN)) found that GLP-1RAs were associated with greater reporting of hair loss compared with other antidiabetic medications; however, disproportionality analyses were negative [3]. Hair regrowth was observed in select cases, and was variably defined as improvement in density, symptom resolution, or hair loss stabilization. A 57-year-old male with insulin resistance, obesity, and AGA experienced hair regrowth and normalized insulin resistance parameters within 6 months of initiating tirzepatide [1]. In 81 patients with CCCA, longer GLP-1RA duration and improved metabolic parameters (e.g., reduced HbA1c) were associated with scalp symptom improvement and/or hair regrowth in 58.0% of patients classified as “GLP-1RA responders”; however, explicit hair regrowth data were not reported; therefore, the number experiencing true hair gains is unknown [4]. Conversely, a cohort study of 283 GLP-1RA users visiting a hospital-based dermatology clinic for any dermatologic diagnosis found mixed outcomes: 32 patients (11.3%) had new-onset or worsening hair loss, while three patients (1.1%) with preexisting hair loss had resolution/stabilization following treatment [5]. Several mechanisms may contribute to the relationship between GLP-1RA use and hair loss or regrowth (Figure 1). Hormonal changes (particularly involving insulin and insulin-like growth factor), rapid weight loss, and the psychosocial stress of managing chronic disease may influence androgen production or the hair follicle cycle, precipitating AGA or telogen effluvium. Changes in dietary intake and potential nutritional deficiencies (i.e., vitamin D) secondary to altered satiety could potentially also contribute. Semaglutide and tirzepatide had the strongest associations with hair loss (ROR values > 1); however, without direct comparison, it is unclear whether their risk is greater than that of other GLP-1RAs. Several types of hair loss (e.g., CCCA, AGA) may improve with glycemic control. Causality cannot be inferred, and study limitations include the predominance of pharmacovigilance data, where reporting bias or differential GLP-1RA prescribing patterns may confound results. Further larger cohort studies are required to determine if certain hair loss disorders may benefit or worsen from GLP-1RA therapy. M.K.B., M.S.L., E.M. and T.K.-H. have no conflicts of interest to declare. J.D. has received honoraria from Pfizer and Vichy, has participated on advisory boards at Pfizer for payment, receives royalties from UpToDate, participates on the Board of Directors for the Scarring Alopecia Foundation, and is the active director of the Evidence Based Hair Fellowship Training Program. The data underlying this study are available in the article and in the supplemental material at https://data.mendeley.com/datasets/k7pydjb66f/1.

Potential clinical application of polygenic risk scores in the estimation of cardiovascular risk in primary care; a structured narrative review

Black tea consumption and the risk of coronary heart disease: a systematic review and meta-analysis of cohort studies.

Mapping the clinical use of inhaled bacteriophages in respiratory infections caused by multidrug-resistant pathogens: a scoping review.

Programs for optimizing the use of antibiotics and their implementation in low- and middle-income countries: A scoping review of methods and reported outcomes.

Conservative management of degenerative rotator cuff tears: A systematic review of long-term clinical outcomes and cost effectiveness.

Association between hypertensive disorders of pregnancy and long-term risk of cardiomyopathy: a systematic review, pairwise, and network meta-analysis.

Preoperative fructosamine is comparable to HbA1c as a short-term glycemic marker for predicting postoperative complications in orthopaedic surgery: A systematic review and meta-analysis.

This review aimed to quantify the association between Type 2 Diabetes (T2D) and the risk of fracture at various anatomical sites by synthesising data from cohort studies. A systematic search was conducted across Medline, Embase, CINAHL and Web of Science databases, from inception to 10 June 2025. We estimated pooled hazard ratios (HRs) with corresponding 95% confidence intervals using random-effects models. This study is registered with PROSPERO (CRD42024548795). This meta-analysis of 22 studies, selected from 6534 screened studies, assessed a total of 13,074,868 individuals (2,644,443 people with T2D and 10,430,425 without T2D). People with T2D have a 25% increased risk of fractures (all anatomical sites) compared to individuals without T2D (HR: 1.25; 95% CI: 1.20 to 1.31). T2D was significantly associated with an increased risk of appendicular lower limb fractures (HR: 1.43; 95% CI: 1.30 to 1.57), upper limb fractures (HR: 1.29; 95% CI: 1.16 to 1.45), osteoporotic/fragility fractures (HR: 1.14; 95% CI: 1.02 to 1.28) and appendicular unspecified fractures (HR: 1.25; 95% CI: 1.05 to 1.48). Subgroup analyses indicated stronger associations in prospective studies. Women with T2D had a significantly higher fracture risk than men. Meta-regression analyses showed that a higher percentage of women participants and a longer duration of T2D were associated with stronger associations between T2D and fracture risk, particularly for lower limb fractures. T2D is associated with an increased risk of fractures, especially in lower limbs (hip, ankle and foot). These findings highlight the importance of targeted fracture prevention strategies and site-specific risk assessment for individuals with T2D. However, due to the heterogeneity among studies, caution is required in the interpretation of these findings.

Clozapine's immune-modulating effects, including neutropenia and suppression of adaptive immunity, have raised concerns about its potential impact on SARS-CoV-2 infection risk and COVID-19 severity in individuals with treatment-resistant schizophrenia. Findings in the literature remain inconsistent. First, we conducted a longitudinal retrospective study in which we analysed 995 outpatients with severe mental disorders receiving antipsychotic treatment to assess the association between clozapine use and SARS-CoV-2 infection and disease severity. Secondly, we performed a systematic review of the literature and searched for studies published up to July 2025 examining the link between clozapine exposure and SARS-CoV-2 infection. Eight cohort studies plus our dataset were meta-analysed using a random-effects model. In our cohort, clozapine users demonstrated a higher rate of SARS-CoV-2 infection (18% vs. 10%, p < 0.001) and increased COVID-19 severity compared to non-users. The meta-analysis comprised 155,945 participants, with individual study ORs ranging from 0.40 to 2.80. The pooled random-effects OR was 1.53 (95% CI: 1.02-2.30, p = 0.044), indicating a significant association between clozapine exposure and increased infection risk. However, high heterogeneity (I² = 91.2%) suggests variation in effects across studies. Clozapine treatment is associated with an increased risk and severity of SARS-CoV-2 infection. Although meta-analytic results support this association, substantial heterogeneity in pooled estimates highlights the need for further research to clarify underlying clinical and methodological factors influencing risk.

Genotype-phenotype correlations and putative modifier genes in SYNGAP1 Encephalopathy.

Incidence of diabetes-related foot disease: results from 2 prospective cohort studies and meta-analysis.

Artificially sweetened beverages and weight change: findings from 3 prospective cohort studies of United States adults.

Effect of Lactobacillus-based probiotics on genitourinary syndrome of menopause in post-menopausal women: A systematic review.

Purity-adjusted prices of illicit drugs are related to drug harms. In this study we examined the time series of purity adjusted prices of crystal methamphetamine and heroin between 2009 and 2020 in Victoria, Australia, and whether this varied by rurality. Data on purity of illicit drug seizures by Victoria Police (2009-2020; n = 47,696) were analysed alongside surveys from two prospective cohort studies of people who use drugs in metropolitan and rural Victoria. Heroin and crystal methamphetamine price, purity, and purity-adjusted price were computed for metropolitan Melbourne (2009-2020) and rural Victoria (2016-2020), adjusted for inflation. Initial rises in unadjusted crystal methamphetamine prices in metropolitan Melbourne were offset by increasing purity levels, leading to a decline in the average purity-adjusted price from AUD 1360 per pure gram (PPG) in 2009 to AUD 330 in 2019, after which it stabilised. Similarly, in rural Victoria, purity-adjusted prices declined between 2016 and 2019, followed by an increase, reaching AUD 600 PPG by 2020. Overall, average purity-adjusted prices were significantly higher in rural Victoria compared to metropolitan Melbourne. The average purity-adjusted PPG for heroin in metropolitan Melbourne increased from AUD 1300 PPG in 2009 until 2014, before declining to AUD 770 by 2020. Overall declines in both crystal methamphetamine and heroin purity-adjusted prices in Victoria suggests that, by 2019, people who purchased these drugs received more drug for a given purchase than in previous years. These changes closely match trends seen in some key harms such as opioid overdose.

The relationship between a frailty index and fall risk in middle-aged and older adults: Findings from three prospective cohort studies - CHARLS, ELSA and HRS.

Neuraxial anesthesia in obstetric patients with rare spinal pathologies: a scoping review.

Postoperative outcomes associated with preoperative oral hygiene in elective surgery: a systematic review and meta-analysis.

Poor sleep is common in people with multiple sclerosis (PwMS). Previous systematic reviews have evaluated intervention effectiveness to improve sleep in PwMS using questionnaires, but no review has comprehensively examined whether sleep interventions improve activity monitor measured sleep outcomes in PwMS. Adhering to the PRISMA guidelines, we searched PubMed, EMBASE, and PsycINFO databases to identify randomized controlled trials, quasi-experimental and cohort studies published from inception to October 2025. A random-effects model was used to estimate the pooled intervention effects of sleep interventions on objective sleep outcomes. Ten studies were included in the review for narrative synthesis, with five eligible for quantitative meta-analysis. Six sleep parameters were assessed via activity monitors: total sleep time, sleep efficiency, total time in bed, sleep onset latency, wake after sleep onset, and frequency of awakenings. Sleep interventions utilised included physical activity, mindfulness, cognitive behavioral therapy (CBT), melatonin, eszopiclone and transcranial direct current stimulation (tDCS). Only sleep efficiency improved following mindfulness interventions. The median length of actigraph wear time was 7 days (range 4 nights to 16 weeks). Study quality appraisal scores ranged from moderate to high, suggesting a low risk of bias. Activity monitors have been used to assess sleep intervention effectiveness in PwMS in studies assessing physical activity, mindfulness and CBT. Objective improvements in sleep were reported following mindfulness and only using one measure (sleep efficiency). However, the small number of included studies limits definitive conclusions. Future trials should consider a wider range of outcome measures and longer time horizons.

The MetALD-ALD Prediction Index: A Phosphatidylethanol-Driven Biomarker Panel for Identifying Individuals With Steatotic Liver Disease and Excessive Alcohol Use.