Over-the-counter (OTC) medications, or those that can be purchased without a prescription, are used by approximately 81% of the United States (U.S.) population. The sale of these products contributes to an annual consumer spending of $30 billion (1). When used as directed, OTC medications are considered safe and can yield positive health outcomes by affording relief for minor ailments and contributing to self-care decision-making (2–4). However, when misused, they can have adverse side effects, interact with other medications, and exacerbate medical conditions (5). The misuse of OTC medications contributes to 178,000 hospitalizations annually (6). Although there are no precise estimates for OTC medication use based on racial or ethnic background, available evidence suggests that self-medication practices are highly prevalent among immigrants in the US (7–9).

In Southern Arizona, OTC usage among Mexican immigrants is an integral part of a wider umbrella of self-care behaviors that are practiced at very high rates on both sides of the U.S.-Mexican border (10, 11). Existing evidence among Mexicans while residing in Mexico shows that patterns of OTC usage reflect socio-demographic characteristics that are correlated to healthcare barriers, such as limited access to healthcare, cultural perceptions, documentation status, and low socioeconomic status (12–14). Upon arriving in the U.S., Mexican migration historically followed a circular pattern, meaning many migrants returned home regularly. However, stricter border enforcement in the 1980s and 1990s made returning home difficult and costly, leading many Mexican immigrants to settle permanently in the U.S. (14). Those who established themselves in the new country faced challenges such as exclusion from insurance programs, fear of deportation, and systemic discrimination linked to their documentation status, which collectively reduced their ability to access necessary medical care (8, 15). Mexican immigrants continued practicing health behaviors acquired in their home country, while undergoing a process of cultural and psychological change known as acculturation (16–20).

Recognizing how individuals identify ethnically within this group is essential, as ethnic identity influences social and political behaviors and attitudes (10). Further, there is a common belief among Mexicans that healthcare facilities in Mexico lack the resources necessary to provide adequate care to patients (13). This perception may lead Mexicans to rely on OTC medications as alternative strategies for treatment (13, 21). In Mexican culture, family is highly valued, often leading individuals to prioritize their family’s financial needs over their own health, which may in turn encourage a preference for self-medicating with OTC medications as a form of cost savings (17, 22, 23). During this process, Mexican immigrants, may adopt attitudes, values, and beliefs of U.S. culture, which may influence health behavior changes. Low acculturation, or less adoption of the host culture’s norms and practices, is associated with increased use of OTC medications in the U.S. within the Hispanic population (18). Additional evidence suggests that the level of perceived discrimination and exclusion in the new country may lead to a preference for self-care practices using OTC medications rather than seeking medical care (18). In addition, OTC medication use among Mexican immigrants in the U.S. has been linked to limited access to healthcare services, skepticism of professional healthcare, and preference for self-medication practices with OTC medications (13, 16, 21, 24). All these factors may limit the ability of individuals to access quality healthcare services, thus leading to a reliance on self-medication use (16, 23, 25).

Although OTC medication use is an important self-care strategy that has filled in gaps in healthcare access among Mexicans in the U.S., research indicates that Mexican immigrants with low income and low educational attainment are more likely to misuse OTC medications. This is an issue of particular urgency along the US-Mexico border, where immigrants are more likely to experience low socioeconomic status than the national average and their respective state populations (7, 18, 26). Residents of this area are more likely to obtain non-prescription medication without consulting a doctor due to its affordability and accessibility (18). The fact that self-medication with OTCs has become more widespread in the border region is likely a strategy to alleviate healthcare costs and other barriers, including hesitancy going to the doctor due to immigration (18, 27).

Although many studies have provided insights into patterns of self-medication practices among the Hispanic community broadly, there is a lack of research exploring the use of OTC medications among Mexican immigrants pre- and post-migration to the U.S., and in particular in the border region (16, 28). This is particularly important since the Mexican immigrant community in the U.S. is characterized by a significant population flow that settles in specific areas, have a family-based immigration focus, and challenges such as language barriers and documentation status issues that makes it of public health importance. Many Mexican immigrant families face challenges understanding complex, English-language medication labels. The lack of familiarity with OTC medication practices in the U.S., combined with language barriers, can lead to dosing errors (1, 14). Using a cross-sectional study design, we aim to describe the patterns of OTC medication use among Mexican immigrants in Southern Arizona. Our objective is to determine self-medication patterns and behaviors among Mexican immigrants in Southern Arizona and to identify key factors influencing these behaviors post-migration.

The use of OTC medications is a significant yet underexplored aspect of health practices among Mexican immigrants in the U.S., particularly in regions along the U.S.-Mexico border. In this study, we aimed to help fill this gap by examining the patterns of OTC medication use among this population in southern Arizona, both before and after migration, as well as the influence of sociodemographic factors on this practice. Study findings revealed shifts in OTC medication use post-migration, with an increase in the use of acetaminophen, NSAIDs, and supplements. These data point to a need to consider the cultural and socioeconomic contexts of Mexican immigrants to mitigate potential health risks associated with OTC medication use.

Study findings suggest that OTC medication usage patterns while in Mexico persist in the U.S., with factors such as the length of stay in the U.S. influencing OTC medication use. For instance, the longer an immigrant has lived in the U.S., the more OTC medications they reported using. Several factors may explain this trend, including high healthcare costs, lack of health insurance, acculturation, the characteristics of individuals using OTC medications, and the nature of interactions between healthcare providers and users that influence how these medications are utilized (18, 32, 33).

In addition to these findings, sociodemographic factors such as sex and marital status were significant predictors of OTC medication use. In this study, men and divorced or separated individuals reported lower OTC use than women and married individuals. This finding may reflect differences in health-seeking behaviors and social support systems. As seen in the literature, men often have different health-seeking patterns than women. For instance, broadly speaking, men engage less in all types of self-care practices than women, which can result from cultural norms (9, 11). Additionally, in Mexican culture, family is highly valued, and self-care practices are shared among family members as part of cultural norms (19, 20). This cultural norm can also explain disparities in OTC medication use between divorced or separated individuals and married individuals. While this pattern had been explored in the literature, future research should analyze the relationship between cultural norms and gender-specific characteristics that influence health-seeking behaviors in Mexican immigrant populations.

In this study, the perceived importance of visiting a physician in Mexico, the presence of chronic conditions in the U.S., or experiencing discrimination when seeking healthcare were not significantly associated with the number of OTC medications used. The absence of this association could be due to characteristics like health literacy and education level. Health literacy, defined as an individual’s capacity to access, comprehend, and apply health information, is an important consideration in understanding health behaviors (9, 34). While low health literacy has been linked to increased self-medication, particularly among individuals who may not fully grasp the importance of seeking medical care, it is crucial to acknowledge that health-related decision-making among Mexican immigrants is multifactorial. Beyond literacy in the traditional sense, broader health-related knowledge, cultural beliefs, and preferences significantly shape healthcare utilization and medication choices (5, 34). Further, paradoxically, high health literacy levels might relate to greater perceived discrimination (35, 36). For example, higher educational attainment migrants perceive more discrimination in healthcare settings compared to those with lower educational attainment (35, 36). In this study, the largest proportion of participants had less than a high school diploma (29.6%). Therefore, those with lower educational attainment may not recognize or report discrimination in healthcare settings due to a lack of awareness or lower expectations of the quality of healthcare (35, 36). Further research is needed to explore the overlap between health literacy, perceived discrimination, and OTC medication use among migrant populations, specifically Mexican immigrants with different educational levels.

The study highlights changes in OTC medication use post-migration. The higher proportion of acetaminophen (34.2%) and NSAID (26.9%) use in the U.S. compared to that reported in Mexico, 29.6% vs. 22.3% respectively, suggests a potential change in pain management preferences, availability, as well as changes in participants’ health status. Changes in health outcomes are expected and can be attributed to high rates of ecologic stressors post-migration and added barriers to healthcare access. Additionally, as populations age, there is a significant rise in the prevalence of chronic diseases (e.g., diabetes, hypertension, depression). These conditions require increased healthcare services, rehabilitation, and daily living assistance. However, access to these services can become more challenging when multiple comorbidities are present, as they elevate healthcare costs and exacerbate the health burden (7, 37, 43). Individuals with chronic diseases may become more familiar with managing their health through prescribed and OTC medications, either to alleviate persistent symptoms or due to the need to handle long-term conditions independently (37, 43). Therefore, it is important to consider the potential risks of OTC medication use among older adults with comorbidities, as it may lead to harmful medication interactions if they are managing multiple chronic conditions simultaneously (38).

Moreover, the simultaneous use of folk remedies and OTC medications can interact in ways that may enhance or complicate health outcomes. People may use them together to complement one another, such as combining herbal teas or homeopathic remedies with OTC medications (e.g., painkillers or cold medicines) (39). However, certain folk remedies, particularly herbal ones, may interact with OTC medications, potentially increasing side effects or reducing their effectiveness (39). For example, some herbs can potentiate the effects of medications like NSAIDs, leading to risks such as stomach irritation (40). Finally, relying on both types of treatments may delay seeking professional care for more serious conditions. Clear communication with healthcare providers about all remedies in use is essential to ensure safe and effective care. It is also important to note that chronic diseases often arise from a complex interaction of genetic, environmental, behavioral, and socioeconomic factors. This can particularly affect migrants who may face new environmental exposures and different lifestyles in the U.S. compared to Mexico (45).

This study found that the use of anti-inflammatories and painkillers increased post-migration, while antibiotic use significantly decreased (21.9% vs. 7.6%). Given that 21.9% of participants reported using antibiotics pre-migration and only 7.6% post-migration, this decline suggests a shift in accessibility, potentially reflecting differences in healthcare regulations, availability, and informal access to them across migration contexts. Although antibiotics are typically prescription-only in the U.S., their reported usage in this study highlights possible gaps in healthcare access and variations in regulatory enforcement. Their inclusion in our analysis provides valuable insight into self-medication trends and public health concerns within this demographic. However, we acknowledge that categorizing antibiotics alongside OTC medications may not fully capture the complexities of access and availability in diverse healthcare settings.

Contributing factors that could explain lower levels of antibiotic use in the U.S. compared to Mexico include documentation status and medication regulations. Since the purchase of antibiotics in the U.S. requires a medical prescription, this finding was expected, whereas the absence of medication regulations prior to 2010 in Mexico significantly influenced the higher use of certain OTC medications before migration (26, 27). Over a decade ago, unrestricted regulations led to the highest antibiotic use rate in Mexico (21, 41). It was not until 2010 that the Commission for Health Risk Prevention (COFEPRIS) prohibited the purchase of non-prescription antibiotics in Mexico. Whereas in the U.S., the FDA strictly regulates antibiotics, requiring prescriptions from licensed healthcare professionals (38). While regulating antibiotic use could help control its misuse, a decline in antibiotic usage may suggest barriers to healthcare access in the U.S. Active public health campaigns are crucial for promoting the responsible and safe use of antibiotics and increased regulatory guidelines and initiatives may help reduce antibiotic use.

In addition to this shift in antibiotic use, people living along the border tend to travel to Mexico due to its medication affordability and accessibility, specifically antibiotics. Another possible explanation for the lower proportion of participants reporting antibiotic use in the U.S. can be attributed to documentation status. Approximately one-quarter of the study sample was undocumented, which may have limited their ability to return to Mexico to obtain antibiotics or to have access to U.S.-based medical services (26, 27, 41). Despite efforts to mitigate healthcare disparities among immigrants in the U.S., such as the Affordable Care Act (ACA), the fear of deportation can contribute to seeking healthcare access, leading to reliance on OTC medications (14).

Lastly, despite these regulation efforts, the border region is a major entry point not only for OTC medication smuggling but also for prescription and illicit substances (14, 42). The cross-border movement of these medications complicates efforts to regulate their safe use in this region. In addition to the challenges faced in this geographical area, undocumented immigrants may avoid seeking necessary health services due to fear of deportation or being reported to immigration authorities. Therefore, their decision to actively manage their health increases (14). For instance, through the self-dispensation of OTC medication, motivated by barriers to accessing medical care as well as a preference for maintaining culturally rooted practices (10). However, further research is needed to understand the long-term health impacts of self-dispensed medication, cultural practices in health decision-making, and the effects of immigration policies on healthcare access in the U.S.-Mexico border.

This study is one of the first to examine OTC medication use patterns among Mexican immigrants in Southern Arizona. The findings contribute to a better understanding of self-medication practices among this population and reveal that patterns of OTC medication use observed in Mexico often persist post-migration. There was an observed increase in the use of acetaminophen, NSAIDs, and supplements post-migration, while the use of antibiotics declined. Sociodemographic factors, such as gender, marital status, and length of stay in the U.S., were significantly associated with the number of OTC medications used. These results suggest that personal characteristics and migration-related experiences may influence self-care behaviors. Further research is needed to explore the implications of these patterns for health outcomes, investigate the various interrelated factors shaping OTC medication use, and examine the specific ailments for which these medications are being used among immigrant populations.