Managing my own health! An ancillary outlook on pharmaceutical and health supplements consumption (2024)

1. Introduction

The shock wave of the COVID-19 pandemic has fostered a trend towards self-care among consumers. Enhanced access to medical knowledge has enabled individuals to take charge of their own health care and well-being (Rovira etal., 2013). Following the recommendations from Malaysia’s National Pharmaceutical Regulatory Agency (2024), this study defines pharmaceuticals and health supplements as products intended to supplement diets and enhance the health and functionality of the human body. These products are available in various forms, such as tablets, liquids, capsules and powders, and are packed with minerals, vitamins, fatty acids, amino acids, probiotics, enzymes or other bioactive components. The growing focus on disease prevention has significantly increased the demand for pharmaceuticals and health supplements. This rising consciousness has positioned the Asia Pacific region as the second-largest market for these products, securing 31% of the market in 2018 (Grand View Research and Inc, 2019a).

On the other hand, Malaysia bears the unfortunate label of being the most overweight country in Southeast Asia (Ng etal., 2014). Yusoff’s (2015) report, which reveals a 1:4 ratio of diabetic to non-diabetic individuals in the nation, highlights the pressing health issues. As a result, the local focus has intensely shifted towards health-care products. This emphasis is evident in Malaysia’s 2018 national budget, where RM1.6bn, RM2.5bn and RM27bn were allocated for health-related consumables, medical supplies and public health care, respectively (Malaysian Ministry of Finance, 2018). The global pharmaceutical and health supplement market, anticipated to reach US$194.63bn by 2025, showcases its burgeoning potential internationally (Grand View Research and Inc, 2019b).

Yet, deciphering consumer preferences for pharmaceuticals and health supplements remains intricate for enterprises. Although consumption patterns are generally linked to environmental factors (Dickinson and MacKay, 2014; Kofoed etal., 2015), intrinsic elements such as gender variances (Conner etal., 2001), ageing populations (Dickinson and MacKay, 2014), educational backgrounds (Yuan etal., 2015) and socio-economic standings (Adeline and Delattre, 2017) also play roles in product utilisation. However, these elements do not fully encompass consumers’ access to health-related data, which is pivotal for making informed choices. A relevant example is Pharmaniaga Bhd, a Malaysian pharmaceutical company, which faced a staggering loss of RM552.3m due to the overstocking of Sinovac vaccines. Coupled with the vaccine’s brief shelf life and decreasing demand, this oversight resulted in a significant financial loss and a 15.4% reduction in market value in a brief period (Salim, 2023). Hence, understanding consumer intentions and preferences becomes vital for pharmaceutical entities in navigating the dynamic realm of personal health care.

Furthermore, the market dynamics mentioned earlier closely resonate with the theory of planned behaviour (TPB), which identifies determinants of behavioural motivations and actions (Ajzen, 1991; Conner etal., 2003). However, the theory lacks consideration of how past experiences might influence current decisions within its framework (Godin etal., 1993). This model’s predictive aspects highlight the distinct influence of previous actions on current intentions (Towler and Shepherd, 1991). Subsequent research proposes the use of TPB as the foundational theory for understanding the effects of advertising on consumption across diverse cultural contexts (Chetioui etal., 2021). Furthermore, in combination with comprehensive marketing strategies, advertising has been shown to have a direct correlation with tangible product consumption (Esteves Pairazaman etal., 2022). Cham etal. (2021) specifically highlighted the profound impact from advertising campaigns and social media promotion on medical branding, and a similar impact is anticipated within the pharmaceutical and health supplement domains.

In addition to the above, the introduction of stringent government policies, such as the Control of Drugs and Cosmetics Regulations 1984, Dangerous Drug Act 1952 and Poison Act 1952, has made marketing challenging due to concerns about misleading information and the potential for false claims, all in the name of consumer protection (Hassali and Shakeel, 2020). However, strict adherence to these regulations can enhance the credibility of advertising messages, given the assurance of government-approved safety. Since the preference for culturally aligned pharmaceutical products depends on individual values, religious convictions, decision-making capacity and access to information (Kasri etal., 2023; Widyanto and Sitohang, 2022), promoting specific qualities (e.g. Halal certification) becomes deeply intertwined with numerous internal variables. In this context, Bharskar and Siddheshwar (2020) study on refined digital marketing tactics for pharmaceutical supplements emphasises the intricate relationship between advertised items and consumer requirements, transcending conventional mass marketing techniques. In Malaysia’s diverse marketplace, there has been a notable shift from collectivism to individualism concerning the adoption of pharmaceutical and health-oriented products, reflecting the country’s rich cultural and historical tapestry. Yet, there has been limited exploration into discerning these subtle differences, as highlighted in the TPB model, when determining and implementing an appropriate advertising strategy.

Against this backdrop, the present study aims to delve into the Malaysian consumer landscape to:

• pinpoint factors steering the consumption of pharmaceutical and health supplements;

• scrutinise the role of past behaviours on prevailing consumption trends;

• evaluate the intermediary effect of perceived behavioural control on the bond between past behaviour and consumption intent; and

• examine the moderating impact of advertising.

2. Literature review

Predicting consumer consumption patterns accurately is a pivotal advantage in the pharmaceutical and health supplement industry. The theory of reasoned action sets the stage by shedding light on various factors influencing consumers’ intentions and actions (Sheppard etal., 1988). Building upon this foundation, the TPB introduced the concept of perceived control, deepening our understanding of external elements that influence purchase intentions (Ajzen and Fishbein, 1980). The applicability of TPB in understanding health-related behaviours is accentuated by Malek etal. (2017). Qi and Ploeger (2019) further demonstrated the theory’s applicability, associating healthy product selections with factors such as personal backgrounds, self-efficacy and other individual considerations. While TPB offers an extensive framework for deciphering health-conscious consumption, it also recognises the influence of numerous external determinants. These include product origin, lifestyle requirements, technological aspects, health benefits, ethical considerations, incentives and product accessibility (Nardi etal., 2019). Hamilton etal. (2020) used TPB to examine the dynamics between personal, social and environmental factors in health-driven behaviours, emphasising the moderating effect of past consumption experiences. Cheng etal. (2019) observed that attitudes towards health-related consumption and physical activity occasionally differ due to varying attitudes, societal standards and perceived control. Nevertheless, the relevance of TPB in explaining health-oriented purchases has been solidly affirmed by Carfora etal. (2019).

Shifting our focus to Malaysia, the nation’s pharmaceutical industry is growing and flourishing. Predicted to contribute RM10bn to the GDP by 2024, the industry, valued at RM7.5bn in 2018, proudly hosts 445 registered entities (Pharmaceutical Association of Malaysia, 2024). Revenue figures from 2022 place the sector’s valuation at US$1736.74m, with an anticipated annual growth rate of 2.77% expected from 2023 to 2027 (Statista, 2023). Within this thriving environment, product attributes significantly influence consumption trends, with choices often guided by individual requirements and acquired knowledge (Ting etal., 2019). Given the facts highlighted above, the TPB emerges as a suitable framework to elucidate the primary drivers of pharmaceutical consumption in Malaysia.

According to the literature, it was reported that different perceptions regarding the effectiveness and value of health products shape the brand preferences of Malaysian consumers towards pharmaceutical products (Ting etal., 2019). While Koh and Goh (2021) used the TPB to uncover the cognitive foundation of pharmaceutical self-care in Malaysia, aspects such as individual convictions about health benefits and knowledge concerning specific products have received limited exploration. This observation underscores the need for a more in-depth analysis of consumer convictions, particularly focusing on anticipated product effectiveness, societal acceptance and individual confidence in the Malaysian context.

At the core of attitude formation lie behavioural beliefs, which represent an individual’s evaluative judgements regarding the potential consequences of a behaviour (Ajzen and Fishbein, 1977). This concept encompasses both the anticipated outcomes of an action and its perceived value (Ajzen, 1991). Such convictions have been directly associated with attitudes that promote healthy lifestyles, as illustrated by Kim etal. (2018) and supported by Montaño and Kasprzyk (2015). Mister (2017) associated increased consumption of pharmaceutical and health supplements with motivations rooted in personal well-being. Individual’s perspectives regarding potential health threats and the inherent benefits of preventive measures shape their attitudinal positions (Huang etal., 2020). As a result, it is proposed that perceived health benefits act as predictors of a positive attitude towards the consumption of pharmaceutical and health supplements. As such, the following hypothesis is postulated:

Normative beliefs further illuminate societal influence within the examined industry. Introduced by Ajzen (2006), this variable is conceptualised as one’s perception of societal acceptance. Two main components are considered: firstly, how significant individuals within society perceive a particular behaviour, and secondly, the individual’s willingness to comply with these societal expectations (Bicchieri, 2006). Building on this, Ajzen and Fishbein (1980) posited normative beliefs as a precursor to the subjective norm. Fang etal. (2017) reinforced this concept, indicating a significant causal relationship between normative beliefs and subjective norms, especially in sustainable living. While an individual’s awareness of societal perceptions influences intentions towards organic consumption (Wang and Wei, 2012; Kim and Chung, 2011), it is believed that subjective norms often guide actual intentions. The literature reviewed emphasises the profound influence of individual perceptions on societal acceptance, particularly concerning the pressures surrounding the consumption of specific pharmaceuticals and health supplements. With this in mind, the following hypothesis is proposed:

Furthermore, control beliefs for the present study are defined as individuals’ general sense of control regarding the consumption of pharmaceutical and health supplements (Ajzen, 1991). While tablets, capsules and soft gels are the preferred forms for health supplement consumption, there is an expectation of growing popularity for powder-based products due to their user-friendliness (Grand View Research and Inc, 2019a). Factors such as ease of consumption and aligning with consumers’ preferences should be taken into account. There is an increased recognition of control beliefs related to improved health among ageing populations. Perceived control over one’s actions directly motivates positive health-inducing behaviours (Drewelies etal., 2018). This motivation often relates to an individual’s self-efficacy in adopting certain behaviours after evaluating potential factors that might affect those behaviours (Lachman etal., 2011). Beyond wellness attributes, other characteristics promoting convenience in the consumption of pharmaceutical and health supplements are also acknowledged. Hence, the following hypothesis is proposed:

Based on the TPB, perceptions formed can potentially precede intentions towards actual consumption behaviours. Behavioural intention denotes a person’s readiness to adopt a specific behaviour (Cham etal., 2016; Cham etal., 2022). Meanwhile, attitudes, subjective norms and perceived behavioural control are seen as antecedents to such behavioural intention. The degree to which each conceptual variable impacts health-related consumption varies based on individuals’ perceptions of healthy living, product safety, awareness of societal and environmental conditions and personal quality of life (Fleșeriu etal., 2020). As articulated by Eagly and Chaiken (2007), attitude is a disposition of approval or disapproval determined by evaluating a specific offering. It encompasses consumers’ subjective evaluations of the outcomes of consuming pharmaceutical and health supplements and their emotional assessment of the importance of those outcomes. Given the relationship between perceived outcomes and formed attitudes, Ajzen (2001) proposed the mediating effect of attitude on behavioural intention through behavioural beliefs. Attitude has also emerged as the predominant predictor of the consumption intention of pharmaceutical and health supplements among female consumers (Conner etal., 2003). Similar logic has driven the impact of scepticism about a product’s effectiveness or inherent health risks on the intention for trial or adoption, supporting a notable correlation between these variables (Cham etal., 2020a; Soveri etal., 2021). Therefore, the attitude formed towards pharmaceutical and health supplements directly influences consumers’ behavioural intentions. Hence, the H4 for the present study is presented below:

Influenced by both normative and informational social aspects, social influence is the effect of societal elements on individual actions (Deutsch and Gerard, 1955). Specifically, the normative norm predominantly reflects the group’s overall influence. Termed as the “injunctive norm” by Rivis and Sheeran (2003), Cialdini etal. (1991) described norms as actions mutually accepted within a society. Consequently, pharmaceutical practitioners often harness social trends and shifts influencing health-care consumption. Several studies have emphasised this as vital to social sustainability by impacting operational intentions (Fang etal., 2017; Abrahamse and Steg, 2009), although this view has been contested by White etal. (2008). Gong etal. (2019) also positioned the perceived norm as a significant influencer alongside reliability and perceived benefits in persuading health-related endeavours. More recent research on consumer behaviour has identified a causal relationship between subjective norm and purchasing intention (Teng and Wang, 2015). Contrary to Western populations, which tend to be more individualistic, the influence of the community was highlighted in research by Tangkiatkumjai etal. (2020) among Asian populations regarding health-related supplement consumption. Given the fact illustrated above, it can be hypothesised that:

Behavioural control delves into the perceived ease or difficulty of performing a specific action (Ajzen, 2005). Rooted in Bandura’s (1982) concept of perceived self-efficacy, it gauges one’s belief in their ability to execute tasks and navigate challenges. As Ajzen (1985) noted, when behaviours are not entirely within voluntary control, intention is heavily influenced by perceived behavioural control. While Kiriakidis (2015) identified perceived behavioural control as a direct precursor to intention, they distinguished it from actual behaviours. Johe and Bhullar (2016) introduced a nuanced perspective, suggesting that perceived behavioural control intertwines with self-identity and societal norms. Conversely, a perceived lack of self-efficacy, especially in relation to health precautions, can lead to reluctance to take specific actions (Hanson etal., 2015). In the context of pharmaceutical and health supplements, perceived behavioural control assesses available resources and potential barriers, such as outlet locations and financial constraints, which might be beyond a consumer’s control. Based on this establishment, the following hypothesis is proposed:

The TPB, comprehensive in its approach to understanding social behaviours, does not entirely capture the nuances of repeat purchases and consumption – a crucial aspect for pharmaceutical companies aiming for enduring market engagement. Aarts (2007) drew a connection between past behaviour and intention through habit formation, a link further reinforced by Sandberg and Conner (2008), who noted a significant increase in the predictive power of intention when incorporating past behaviour. This aspect spotlights consumer repurchase patterns, offering insights into consistent behaviours (Smith etal., 2008; Ouellette and Wood, 1998). Indeed, Ajzen (2011) identified past behaviour as the primary predictor of behavioural intention.

However, Ajzen (2005) later questioned the direct relationship between past behaviour, intention and subsequent actions, suggesting that past behaviour mainly illustrates behavioural consistency, which becomes less relevant when other significant predictors of intention are present. Some scholars, such as Sommer (2011), argued that habits evolve from past actions into established behaviours, while others, such as Sheeran etal. (2005), believed that past behaviours, combined with conscious determinants, shape reasoned and semi-automatic behaviours. Kulik etal. (2019) emphasised the role of foundational knowledge in shaping attitudes and behaviours, contrasting with Godrich etal. (2019), who highlighted the importance of confidence gained from previous experience.

Interestingly, Ajzen (1991) proposed that past behaviours might indirectly influence potential behaviours through perceived behavioural control. Sultan etal. (2020) highlighted how product or brand familiarity can shape consumer expectations and satisfaction. Knowledge and familiarity, stemming from past engagements, factor into greater perceived control before consumption. The intricate relationship between past experience and current behaviour, as suggested by Norman and Conner (2006) and Smith etal. (2007), leads us to the subsequent hypotheses:

In marketing, advertising stands as a potent communication tool, used to convey persuasive messages across various media platforms (American Marketing Association, 2024). Its efficacy lies in shaping one’s perceptions, emotions, attitudes and behaviours (Cham etal., 2020b; Chen etal., 2017; Fam etal., 2023). The dual capability of advertising to both inform and persuade has cemented its role as an essential business instrument (Bhutada and Rollins, 2015). Both price and advertising are recognised as crucial determinants of consumer preferences (Amer etal., 2019; Cham and Easvaralingam, 2012; Cheah etal., 2019).

Research consistently acknowledges the impact of advertising on consumer attitudes, behaviours and intentions (Mogaji and Danbury, 2017; Sameti and Khalili, 2017). Sameti and Khalili (2017) specifically emphasised the direct influence of commercial advertising on consumer behaviours and intentions. In contrast, Hoque etal. (2019) spotlighted the moderating role advertising plays between consumer attitudes and experiences. Given this backdrop, the following hypotheses are posited:

Based on the previously discussed evidences, proposed conceptual framework with regards to the hypothesised interrelationships for the current study has been illustrated in Figure 1.

3. Research methodology

This study used a quantitative approach for data collection, with measurement items for the TPB variables adapted directly from Conner etal. (2001). The current construct encompassed eight items for behavioural beliefs, ten for normative beliefs and 12 for control beliefs. Six items were then used to measure consumers’ attitudes, three for subjective norms, six for perceived behavioural control and four for the intention to consume pharmaceutical and health supplements. Furthermore, three items for past behaviour were adapted from Albani etal. (2018) to assess current pharmaceutical and health supplement usage, with a six-item scale by Cham etal. (2021) used to operationalise the perceived impacts of advertising. The detailed measurement items for all the constructs included in this study are listed in Appendix.

The measurements for all the items were based on a five-point Likert scale, ranging from 1 = strongly disagree to 5 = strongly agree. A pre-test among 15 industry experts and a pilot study among 40 respondents were conducted prior to data collection to ascertain the questionnaire’s clarity. The face validity of each variable was established following the verified relevance and non-ambiguity of all items. Statistical analyses were then conducted using Analysis of Moment Structures version 25, alongside with the Statistical Package for the Social Sciences (SPSS) version 25.

4. Research results

5. Discussion and implications of findings

The results fundamentally affirm a direct correlation between behavioural beliefs and attitudes towards consuming pharmaceutical and health supplements. Echoing the findings of Kim etal. (2018) and Montaño and Kasprzyk (2015) regarding result-oriented consumerism, a significant segment of the pharmaceutical market emphasises the tangible benefits of such consumption, particularly in terms of product value and advantages. This perspective is further supported by Choe and Kim (2018) and Kim and Eves (2012), which delve into consumers’ meticulous considerations of health-related value in food intake. As such, a personalised approach to self-care aligns with each individual’s unique nutritional requirements. While advertising messages should be specialised, avoiding over-generalising health benefits, the current data accentuates the importance of conveying specific product values. For instance, supplements targeting body weight control differ from those focusing on mental rejuvenation. Therefore, the “one-size-fits-all” notion is less favoured in marketing due to its lack of differentiation. Instead, the competitive landscape, which acknowledges individual needs, necessitates more tailored messages addressing specific wellness concerns.

Moreover, normative beliefs emerge as significant determinants of subjective norms. This is reinforced by prior studies such as Wang and Wei (2012) and Kim and Chung (2011), which indicate that the choice of supplements consumed by the public is not solely for individual wellness but is also influenced by prevailing societal trends and motivations. This suggests that venturing beyond individual needs could cater to a broader societal segment, enhancing market targeting. It is plausible that consumers within specific health-related categories might have mutual preferences for certain pharmaceutical supplements. For instance, older, physically active consumers might gravitate towards products to bolster bones and muscles. Insights from Jennings (2019) emphasise the value of consulting peers when faced with uncertainty, reinforcing the concept of shared cognition. This aligns with the notion of collective or modified perceptions influenced by family, acquaintances or societal views on health-related endeavours, as discussed by Linden (2015) and Sriram etal. (2018). In essence, these findings underscore the necessity for marketing strategies that resonate with distinct segments, allowing potential consumers to relate to the positive experiences of similar users. For pharmaceutical marketers, the goal would be to craft messages that highlight benefits endorsed by the public. Schultz etal. (2014) have also spotlighted the pivotal role of online buzz marketing in propagating word-of-mouth, suggesting that achieving subjective norms can be realised through endorsem*nts from satisfied users, such as online influencers. Nonetheless, the emphasis remains on crafting targeted advertising messages that transparently communicate the genuine benefits of consumption.

Furthermore, consumers’ perceived behavioural control has been directly linked to their control beliefs. This implies that an individual’s perception of self-care hinges on evaluating internal and external motivating factors. Such a perspective aligns with the works of Loebnitz and Grunert (2015) and Yang etal. (2018), emphasising environmentally driven motivations as pivotal for sustained consumption patterns. Building on these insights, there is a pressing need for an objective approach in retailing pharmaceutical and health-related products, focusing on accessibility and availability. As highlighted by Yang etal. (2018), mere attitudes and subjective norms might not translate into actual consumption, especially when challenges arise. Therefore, without accessible channels, differentiated marketing strategies in the pharmaceutical realm might fall short. For instance, the desire to purchase a specific skincare supplement is moot if geographical constraints hinder its acquisition. Consequently, a significant part of effective advertising pivots on ensuring expansive availability of consumption avenues, simplifying the purchase process – browsing, selecting, payment and delivery – for targeted customers. Concurrently, the intrinsic motivation of self-care in the market should not be eclipsed by the overarching concept of behavioural control. Drawing from Gist and Mitchell (1992), who highlighted the role of self-esteem, self-efficacy and perceived competency in task execution, the present findings reiterate the cornerstone role of advertising messages in fostering a belief in one’s capacity to manage wellness through pharmaceutical consumption. Going beyond the mere focus on targeted marketing, the emphasis rests on nurturing consumer awareness about their personal well-being, making it foundational to the attention given to the benefits of these endeavours.

Unsurprisingly, belief factors have emerged as dominant predictors of pharmaceutical product consumption intentions. However, what sets this study apart from prior research by Alami etal. (2019), Cham etal. (2018), Conner etal. (2001) and Lee etal. (2016) are the pronounced influences of attitude over perceived behavioural control and subjective norms in shaping the intrinsic intention for pharmaceutical-based self-care. In line with Schultz etal. (2014), a leaning towards individualism over collectivism is evident based on the distinct wellness needs of consumers. The pursuit of tailored benefits nudges them towards choosing readily available or familiar products rather than venturing into the unknown or less accessible options. Although past insights have underscored the importance of reference points and self-care motivations as foundational elements shaping market behaviours, the current findings emphasise the primacy of effectively communicating product benefits to target segments. Ultimately, consumers are more swayed by tangible benefits (e.g. ageing prevention) than by broad claims like “80% of the public is using this product” or motivational taglines like “You can take charge of your own health!” This accentuates the imperative of clear differentiation in advertising messages regarding functionality and genuine benefits. Hence, a precise alignment between marketed products and selecting an appropriate consumer category is favoured over a blanket, undifferentiated marketing approach.

While the current study, grounded in the TPB paradigm, supports findings by Sheeran etal. (2016) on the collective significance of the investigated independent variables towards health-related intentions, it stands in contrast to other studies. These studies, such as those by Bohen etal. (2016), Gupta etal. (2018) and Sriram etal. (2018), underscore the significance of specific variables such as attitude and perceived behavioural control. Such discrepancies raise questions about the paper’s generalisability from an academic perspective. However, when viewed within the context of the Malaysian market, this investigation suggests practical applicability for effectively targeting domestic consumers. Reiterating from earlier discussions, the emphasis on product functions and benefits solidifies its position in shaping market intentions, ensuring the effective delivery of the desired message. Recognising the significance of societal norms and behavioural controllability, it becomes evident that a nuanced market categorisation can negate the push for excessive customisation. The prevailing findings highlight consumers’ pronounced focus on usability. This suggests potential shifts in product choices under circ*mstances such as:

• the discovery of a product that aligns better with their expectations;

• a reshaped perception of a currently used product due to influence from a reference group advocating an alternative with superior value; and

• unexpected unavailability of a current product, prompting the selection of an alternative without compromising health outcomes.

This poses a question for pharmaceutical stakeholders: How can they align with the needs and satisfaction-driven preferences of their target audience in Malaysia? This becomes paramount for product development and marketing strategies. In this context, a blend of positive word-of-mouth and product accessibility becomes vitally effective, especially when clients are convinced of the genuine benefits and values of the marketed supplements aligning with their wellness needs.

Building on this, the TPB paradigm, which emphasises current determinants, has been enriched by insights regarding the significant role of past behaviour in influencing the intention to consume pharmaceutical products. This perspective aligns with the works of Lim and Cham (2015) and Sheeran etal. (2016). However, it is essential to consider the findings of Hagger etal. (2018), who shed light on the “past behaviour effect”, where repeated consumption is subconsciously influenced by prior behaviours. The tendency for consumers to adhere to familiar consumption patterns, especially when previous experiences were positive, is noteworthy. This observation, when juxtaposed with earlier discussions on benefit-seeking, societal acceptance and controllability, introduces a fresh perspective on brand loyalty rooted in past experiences. Such a perspective challenges the established paradigm of minimal switching costs in scenarios where there is no prior experience. While the allure of products boasting enhanced targeted benefits, perceptions shaped by buzz marketing, and sheer convenience can be compelling, these factors may be counterbalanced by deep-rooted familiarity and resistance to change. Consumers’ attachment to familiar products may hinder efforts to introduce variations in supplemental needs. The overarching challenge lies in the quest for market expansion, particularly in capturing market share from neighbouring competitors. However, when viewed in conjunction with the TPB components, the significance of this variable offers a silver lining. The benefits of supplements remain a persuasive advertising message, reinforcing consumer confidence and encouraging trials and adoption. However, this is contingent upon competing products delivering superior value compared to established pharmaceutical supplements.

The indirect influence of past behaviour on the intention to consume pharmaceutical products is further clarified through the mediating effect of perceived behavioural control. Drawing from the findings of Bagozzi and Edwards (1998) and Gollwitzer and Oettingen (1998), the importance of making lifestyle changes to adopt healthier behaviours becomes evident. An individual’s commitment to these changes, as indicated by their self-efficacy for self-care, is shaped by their previous health-related endeavours. Studies by Aarts (2007) and Mengel etal. (2016) emphasise that repeated behaviours often reduce risk perception, leading to behavioural automation. Consequently, consumers’ confidence in managing their health is influenced by past experiences that provide them with robust knowledge about product efficacy. Beyond product-specific expectations and societal influence, this fosters internal confidence among consumers towards repeat purchases, particularly when the core wellness benefits have been consistently realised through product usage. This reinforces the earlier assertion that retaining existing customers is often easier than acquiring new ones. Familiarity with regularly consumed supplements serves as a barrier to experimenting with new products. The interplay between past behaviours and the TPB paradigm, which emphasises enhanced self-care ability and controllability, underscores the importance of pharmaceutical practitioners prioritising product availability and convenience to modify established behaviours and perceptions. Mullan etal. (2016) highlighted the feasibility of behavioural change through interventions, suggesting a balance between delivering product value and the amount of change required for a new health-related consumption routine. For instance, this could mean consuming a similar number of tablets daily but with a product that offers superior nutritional value compared to its competitors. The overarching message for marketers is to focus on product excellence without undermining consumers’ perceived ability to manage their wellness.

On another front, the moderating effects of advertising on the relationships between attitude, subjective norm and consumption intention overshadow its direct influence on perceived behavioural control and past behaviours. Echoing the insights of Hussain etal. (2020), advertisem*nts play a pivotal role in nurturing long-term consumption by cultivating market interest, shaping individual identity and exerting societal pressure. Concurrently, they shape perceptions about a brand’s integrity and market positioning (Hussain etal., 2020). This nuanced relationship diverges from the conclusions drawn by Amer etal. (2019) and Cheah etal. (2019), which emphasise personal preferences. Essentially, consumers’ motivation to explore new pharmaceutical supplements is influenced by the messages advertised about product benefits and the societal buzz generated by these advertisem*nts. However, merely communicating a product’s value will not sway consumers if they lack confidence in or access to the said products. While a positive attitude towards advertised products can trigger an intention to try them, such motivation can diminish if the new product does not align with their convenience and self-efficacy needs. Hussain etal. (2020) affirmed that sustainable behavioural decisions depend on corresponding external factors. Thus, pharmaceutical companies must design strategies that foster positive perceptions towards heavily advertised health supplements, ensuring convenience and accessibility that align with their target market’s attributes.

Finally, the prominence of key variables within the TPB, as proposed by Ajzen (1991), highlights the intricate interplay between beliefs, perceptions and decisions. However, this framework tends to prioritise immediate gratification over long-term loyalty. The importance of product-related knowledge in shaping market expectations and competitiveness is underscored by Suchánek and Králová (2019). This suggests the predictive power of past behaviours on current consumption patterns, especially in a domain such as health care, where individual needs related to manageability, knowledge, hedonism, security and sustainability often take precedence over societal opinions. The TPB’s limitation in accounting for longitudinal experiences introduces past behaviours as an additional variable, offering a richer perspective for social research. Given the rapid evolution of pharmaceutical and health supplements (Ghazali etal., 2017), this presents a promising avenue for future academic research, which inevitably challenges the relevance of past consumption data in predicting future consumption patterns.

6. Limitations and conclusion

Several limitations emerged during the course of this research. One primary limitation was the use of non-probability sampling, which may have overlooked equal representation across different population subsets. Moreover, the quantitative approach used for data collection might not capture the depth and nuances that a qualitative method could offer in understanding the underlying reasons for respondents’ perceptions. The focus of this study on the Malaysian pharmaceutical market also raises questions about the broader applicability of its findings. Future research might benefit from using probability sampling methods, such as random sampling, in the broader market context to ensure more comprehensive industry representation. Incorporating qualitative analysis could also provide a richer understanding of consumers’ perspectives and preferences.

The core focus of this study extended the TPB paradigm to explore determinants of consumers’ intentions to consume pharmaceutical and health supplements, with an emphasis on the significance of past behaviours and advertising. As the pharmaceutical industry shifts from a seller-centric to a consumer-centric approach, past behaviours and advertisem*nts play crucial roles in ensuring market retention through previous experiences and sustainable positioning via repeated purchases and market expansion. In today’s age, where consumers are empowered with vast amounts of health care-related information, it is imperative for pharmaceutical brands to devise and execute targeted business strategies that cater to diverse consumption needs. The findings of this study guide practitioners towards leveraging specific environmental and cognitive factors to enhance the appeal of certain pharmaceutical and health supplements, aiming to attract first-time users. Building trust between suppliers and consumers and delivering value that exceeds users’ health care and pharmaceutical expectations becomes vital in nurturing and maintaining consumer loyalty.