Factors linked to hair loss in people using GLP-1 receptor agonist medications

The use of weight loss medications has seen a marked increase in recent years as individuals strive not only for improved body composition but also for better overall health outcomes. Among these medications, glucagon‐like peptide‐1 receptor agonists (GLP‐1RAs) have gained particular prominence due to their effectiveness in achieving significant weight reduction and improving metabolic parameters in patients with type 2 diabetes mellitus and obesity [1, 2]. GLP‐1RAs including Mounjaro, Ozempic, Saxenda, or Victoza are increasingly used in clinical practice and have transformed the therapeutic landscape for metabolic diseases [3, 4].

However, as the prescription of GLP‐1RAs grows, attention is also turning to their side effect profiles. Gastrointestinal symptoms such as nausea and vomiting remain the most commonly reported adverse effects [5]. Injection site reactions and, more rarely, cutaneous manifestations—including hypersensitivity reactions and autoimmune blistering disorders—have also been documented [6]. Despite this growing body of knowledge, one area that remains understudied is the occurrence of hair loss associated with GLP‐1 receptor agonist (GLP‐1RA) therapy.

Hair loss whether due to telogen effluvium, androgenetic alopecia, or other mechanisms is a significant concern for many patients, impacting the quality of life and potentially influencing adherence to medication regimens. Although some case reports and small studies have noted the potential for drug‐induced alopecia in association with antidiabetic therapies, including teneligliptin and GLP‐1RAs, the true prevalence and risk factors for this phenomenon remain unclear [7]. Of particular interest, recent pooled analyses from large clinical trials have reported an increased frequency of drug‐induced alopecia with characteristics similar to telogen effluvium, among users of GLP1 for weight management, with most cases being mild, transient, and correlating with rapid weight reduction rather than the direct pharmacological effect of the drug itself [8].

Despite increasing anecdotal and clinical evidence, the literature still lacks comprehensive, real‐world data evaluating the predictors, types, and timing of hair loss in patients using GLP‐1RAs—especially outside of tightly controlled clinical trial environments [9, 10]. With the recent approval and increasing utilization of new agents, such as Mounjaro, which have demonstrated impressive weight loss outcomes, it is essential to systematically assess the potential cutaneous and dermatologic side effects including alopecia of these therapies [4].

The present study aims to investigate the frequency, characteristics, and predictors of hair loss among users of GLP‐1 receptor agonists, with a particular focus on Mounjaro. By examining demographic and clinical risk factors, types of hair loss, and the temporal relationship to therapy, this study aims to fill an essential gap in the literature and offer guidance for clinicians and patients on the dermatological safety of these increasingly used medications.

This was a cross‐sectional study conducted in Saudi Arabia, from January to June 2025, involving adults who had used GLP‐1RAs for weight reduction. Data were collected from 254 participants attending clinics for weight loss. Eligible participants were aged 18 years or older, had used GLP‐1RA injections (Mounjaro, Ozempic, Saxenda, or Victoza) for at least one month, and provided informed consent. Individuals with pre‐existing scarring alopecia or on concurrent medications known to cause hair loss (such as chemotherapy) were excluded.

Data for this study were collected using a structured questionnaire administered to participants, which captured a broad range of variables pertinent to the investigation of hair loss among users of GLP‐1RA. Demographic information, including age, sex, nationality, marital status, and employment status, was collected, along with anthropometric data obtained from self‐reported height and weight. Participants were also asked to report their clinical characteristics, including current health conditions (such as hormonal disorders, polycystic ovary syndrome, anemia, thyroid disease, any history of telogen effluvium, and ferritin status). Detailed information regarding GLP‐1RA use was collected, encompassing the specific type of GLP‐1RA, the primary indication for its prescription (such as weight loss, diabetes management, or PCOS), and the duration of use (categorized as less than 3 months, 3–6 months, 6–12 months, or greater than 12 months). The questionnaire further explored participants' hair care practices, including their hair type, washing frequency, and the use of various hair products, such as dyes, straighteners, extensions, and curl enhancers.

Assessment of hair loss was based on self‐reported responses to items inquiring about current hair loss status (yes/no), timing of onset about the initiation of GLP‐1RA injections (chronic, within the first month, 1–3 months, 3–6 months, more than 6 months, or no change), severity of hair loss (mild, moderate, or severe), and progression over time (improved, stabilized, worsened, or unchanged). Additional questions addressed the type of hair fall (whether from the roots or due to splitting) and the approximate number of hairs lost daily (< 50, 50–100, 100–150, 150–200, and > 200).

For statistical analysis, SPSS v29 was used, and descriptive statistics (means, standard deviations, frequencies, and percentages) were used to summarize participant characteristics and features of hair loss. Comparative analyses were performed using the chi‐square test or Fisher's exact test for categorical variables (such as the association between injection type and hair loss prevalence or severity). In contrast, one‐way ANOVA or independent t‐tests were used for continuous variables. To identify independent predictors of hair loss among GLP‐1RA users, a multivariable logistic regression analysis was conducted, with hair loss (yes/no) as the dependent variable. Independent variables included gender, marital status, type of injection, and duration of GLP‐1RA use. Adjusted odds ratios (aOR) and 95% confidence intervals (CIs) were calculated, with statistical significance defined as p < 0.05.

Table 1 presents the demographic and baseline characteristics of the participants. A total of 254 participants were included, with the majority of the sample being female (181, 71.3%), while males comprised 73 (28.7%). The mean age of the participants was 33.28 ± 9.73 years. The average height was 161.47 ± 18.0 cm, and the mean body weight was 77.86 ± 16.17 kg. Most participants were Saudi nationals (243, 95.7%), with a small proportion being non‐Saudi (11, 4.3%). Regarding marital status, 153 (60.2%) were married, 92 (36.2%) were single, and 9 (3.5%) were divorced. In terms of employment, 162 (63.8%) were employed.

Among the weight‐reduction injections used, Mounjaro was the most common (74.0%), followed by Ozempic (19.7%), Saxenda (5.9%), and Victoza (0.4%). The duration of injection use varied, with 104 (40.9%) using injections for 3 to 6 months, 78 (30.7%) for less than 3 months, 48 (18.9%) for 6 to 12 months, and 24 (9.4%) for more than 12 months. The primary indication for injection use was weight loss 121 (87.0%), followed by diabetes 13 (12.2%) and polycystic ovary syndrome (PCOS) 2 (0.8%).

Regarding current health conditions, 87 (34.3%) reported having no underlying condition. Others reported hormonal issues 42 (16.5%), PCOS 34 (13.4%), moderate to severe anemia 33 (13.0%), thyroid disease 20 (7.9%), telogen effluvium within the past year 34 (13.4%), and low ferritin levels 4 (1.6%). Hair types reported included wavy 85 (33.5%), straight 73 (28.7%), curly 52 (20.5%), and dry 44 (17.3%). Most participants reported washing their hair twice a week 156 (61.4%), followed by daily washing 62 (24.4%), once weekly 32 (12.6%), and rarely 4 (1.6%). Over half of the participants, 141 (55.5%), reported no use of hair products, while others used hair dye (75, 29.5%) and hair straighteners (14, 5.5%).

Among the participants, the majority reported experiencing current hair loss (193, 76.0%), while 61 (24.0%) did not report hair loss. Of the 193 patients, 75 (38.8%) noticed it within 1 to 3 months after starting injections, 43 (22.3%) had chronic hair loss predating the injection use, 29 (15%) experienced hair loss within the first month, 25 (13%) within 3 to 6 months, and 4 (2.1%) after more than 6 months. A small proportion, 17 (8.8%), reported no change in hair status.

In terms of severity, 84 (43.5%) described their hair loss as moderate, 69 (35.8%) as severe, and 40 (20.7%) as mild. The progression of hair loss over time varied, with 92 (48.2%) reporting worsening hair loss, 77 (40.3%) noting stabilization, 20 (10.5%) reporting improvement, and 2 (1.0%) indicating no specific duration. Most participants (166, 86%) reported hair falling out from the roots, while 27 (14%) reported hair‐splitting. Daily hair fall volume was reported as follows: 57 (29.5%) lost 50–100 hairs, 46 (23.9%) lost 100–150 hairs, 37 (19.2%) lost fewer than 50 hairs, 31 (16%) lost 150–200 hairs, and 22 (11.4%) lost more than 200 hairs per day. Table 2.

Table 3 presents a comparative analysis of hair loss characteristics across different types of weight‐reduction injections. Among Mounjaro users, 136 (72.3%) reported hair loss, compared to 42 (84.0%) of Ozempic users, 14 (93.3%) of Saxenda users, and 1 (100%) of the single Victoza user. Although differences in hair loss prevalence were observed, the association was not statistically significant (p = 0.116). The onset of hair loss also varied by the type of injection. The most common onset period among Mounjaro users was within 1–3 months (54, 39.7%), similar to that of Ozempic users (17, 40.5%). Chronic hair loss before injection was most frequent among Saxenda users (5, 35.7%). Hair loss onset beyond 6 months was rare across all groups. No statistically significant differences in onset timing were found (p = 0.642).

Hair loss severity differed significantly among groups (p < 0.001). Severe hair loss was most prevalent in Mounjaro users (59, 43.4%) and Saxenda users (6, 42.9%), while Ozempic users most frequently reported moderate severity (25, 59.5%). The only Victoza user reported mild hair loss.

Progression of hair loss over time showed no significant differences across injection types (p = 0.953). In all groups, the majority reported that hair loss had worsened over time, particularly among Mounjaro users (68, 50.0%) and Ozempic users (17, 40.5%). Regarding the type of hair fall, most participants across all injection types reported shedding from the roots, with slight variation (e.g., Mounjaro: 85.3%, Saxenda: 92.9%, p = 0.857). Daily hair fall volume showed no statistically significant difference among the groups (p = 0.259). Hair shedding of 50–100 hairs per day was the most frequently reported range, particularly among users of Saxenda (35.7%) and Ozempic (35.7%). A higher volume of hair loss (> 200 hairs/day) was reported by 28.6% of Saxenda users, compared to 9.5% of Ozempic and 10.3% of Mounjaro users. A single Victoza user reported hair loss of fewer than 50 hairs per day.

Table 4 presents the results of a multivariable logistic regression analysis identifying predictors of hair loss among injection users. Gender was significantly associated with hair loss, with males having lower odds of reporting hair loss compared to females (adjusted odds ratio = 0.36, 95% confidence interval [0.18, 0.70], p = 0.003).

Marital status was also a significant predictor. Compared to divorced individuals, single participants had 6.83 times higher odds of reporting hair loss (95% CI [1.41, 33.15], p = 0.017), whereas married participants had even greater odds (adjusted OR = 9.94, 95% CI [2.10, 46.96], p = 0.004).

The type of injection used emerged as a strong predictor: participants using Mounjaro had significantly higher odds of reporting hair loss compared to those using Victoza, Saxenda, or Ozempic (adjusted odds ratio = 3.02, 95% confidence interval [1.32, 6.91], p = 0.009).

Regarding the duration of injection use, those who had been using injections for less than 3 months (adjusted OR = 1.04, 95% CI [0.36, 2.98], p = 0.940) or for 3–6 months (adjusted OR = 2.38, 95% CI [0.84, 6.74], p = 0.101) did not show statistically significant associations with hair loss. However, those using injections for 6–12 months showed a trend toward significance, with higher odds of hair loss compared to those using injections for more than 12 months (adjusted OR = 3.50, 95% CI [0.99, 12.40], p = 0.053).

Over three‐quarters of participants in our study reported new or worsened hair shedding after initiating GLP‐1RAs. Female participants had substantially higher odds of experiencing hair loss compared to males, a finding consistent with previous studies that suggest women are at a higher risk for drug‐induced alopecia, particularly in the context of physiological stress [8]. This is particularly relevant given that women tend to be more sensitive to hormonal changes, and hair loss in females is often more noticeable and distressing. Furthermore, we found that participants using Mounjaro were about three times more likely to report hair loss compared to those using other GLP‐1RAs. This aligns with pharmacovigilance reports, which suggest that it may be due to its more significant weight‐reducing effects [10, 11]. In our study, 43.4% of Mounjaro users reported severe hair loss, a significantly higher rate compared to Ozempic users, who reported 9.5% severe hair loss. Saxenda users had intermediate rates (42.9%), although the sample size for Saxenda was smaller.

This study suggests that patients using GLP‐1 receptor agonists (GLP‐1RAs) for 3 to 6 months are more likely to experience hair loss, indicating that this period when weight loss is most significant, drug induced alopecia with characteristics similar to telogen effluvium. Participants who had been using GLP‐1RAs for 6 to 12 months showed a trend toward increased hair loss; however, the 3‐ to 6‐month period was identified as particularly susceptible to this side effect. This finding is consistent with the literature, which links rapid weight loss during the first few months of GLP‐1RA therapy to the triggering of hair shedding [2, 12, 13]. Furthermore, the progression of hair loss over time showed that most participants reported hair loss worsening during therapy, with 48.2% indicating an increase in shedding. However, a significant portion (40.3%) reported that their hair loss had stabilized, indicating that in many cases, this drug induced hair loss is similar to telogen effluvium resolves as the body adapts. However, a case report from Saudi Arabia has also documented alopecia areata as a potential adverse effect of GLP‐1 receptor agonists [14]. Additionally, recent studies have highlighted alopecia as a possible dermatologic side effect of GLP‐1RAs, further emphasizing the need to monitor for such adverse events during treatment [15, 16].

Hair loss, even if temporary, can significantly impact a patient's psychological well‐being. Many participants in our study reported moderate to severe shedding, with over one‐third stating that their hair loss worsened during treatment. This mirrors findings from other studies, where alopecia‐related anxiety was identified as a significant concern among patients [8, 17]. Hair loss can lead to emotional distress and decreased self‐esteem, sometimes resulting in early discontinuation of therapy. To mitigate this, healthcare providers should inform patients about the potential for hair loss at the start of GLP‐1RA therapy and reassure them that it is typically reversible. Proper nutritional support, including adequate protein intake and supplementation with iron, zinc, and biotin, is crucial for preventing and managing hair loss. Additionally, screening for underlying conditions, such as thyroid dysfunction, should be considered before starting treatment to support hair health further.

This study has several limitations, including the self‐reported nature of hair loss and the absence of a control group, which makes it challenging to distinguish the effects of weight loss from those of the drug itself. Future research should incorporate objective dermatologic assessments and include a control group of patients using alternative weight‐loss methods better to isolate the specific impact of GLP‐1RAs on hair loss. Additionally, larger studies with more diverse populations are needed to investigate how factors such as gender, age, and genetics affect the risk of hair loss.

In conclusion, this study highlights the significant association between GLP‐1 receptor agonist (GLP‐1RA) therapy and hair loss, particularly in female patients and those using Mounjaro. Although this drug induced alopecia with characteristics similar to telogen effluvium, is a distressing but typically reversible side effect, it can significantly impact patients' emotional well‐being and adherence to treatment. Proactive management, including patient education, reassurance, and proper nutritional support, is crucial in minimizing the psychological and physical effects of this side effect. Further research, including controlled studies with objective assessments, is necessary to gain a deeper understanding of the underlying mechanisms.

Yahya Argobi contributed to the conception, design, and supervision of the study. Norah Saad Jadaan participated in data collection and preliminary analysis. Hind Bader Alshalhoob contributed to the literature review and the design of the methodology. Manar Saleh Alyousef was responsible for interpreting clinical data. Ghaid Mohammed Alotaibi assisted with statistical analysis and data visualization. Hussain Sami Alwesaibie contributed to the validation of the results and the revision of the manuscript. Ibtihal Sultan M. Alshehri participated in manuscript writing and final proofreading. All authors read and approved the final manuscript.

This study was conducted in accordance with the ethical standards of the institutional and national research committees, as well as the 1964 Helsinki Declaration and its subsequent amendments or comparable ethical standards. Ethical approval was obtained from the appropriate ethics review boards of the participating institutions. Informed consent was obtained from all individual participants included in the study.

The authors declare no conflicts of interest.

The authors would like to express their sincere gratitude to their respective institutions for supporting this research: King Khalid University, Majmaah University, King Fahad Specialist Hospital in Qassim, King Saud bin Abdulaziz University for Health Sciences, and Almoosa Specialist Hospital. Special thanks to all participants and colleagues who contributed to the success of this work.

The data that support the findings of this study are available from the corresponding author upon reasonable request.