A DCE and treatment-control design were employed to answer research questions 2, 3, and 4. DCE is a quantitative approach to assess the weight individuals assign to various factors when making decisions, which has risen to prominence as a common survey methodology for investigating a wide range of subjects, including marketing, environmental economics, and healthcare economics (Aizaki et al., 2014; de Bekker-Grob et al., 2019; Szinay et al., 2021; Lizin et al., 2022). Respondents are presented with choice sets containing multiple choices with varying levels of attributes and are asked to choose one of them or none if they do not find any choice attractive (i.e., opt-out option). DCE falls into two categories: unlabeled and labeled. In labeled DCE, options are named to enhance scenario authenticity and clarity, potentially yielding more accurate preference patterns and simplifying label-related effect analyses (de Bekker-Grob et al., 2010; Aizaki et al., 2014). We adopted a labeled DCE because it enables respondents to make choices based on easily identifiable attributes by their labels, making the choice task more realistic and less abstract, and ultimately enhancing the validity of results (de Bekker-Grob et al., 2010).

A treatment-control design reveals the impact of information intervention on consumer preferences by comparing treatment and control groups (Grilli and Curtis, 2021). This study prepared two treatment groups with human health and environmental information or cost-effectiveness information for different menstrual products. Information was provided before answering the DCE-related questions. To ensure their understanding of the information provided, respondents underwent comprehension tests. We excluded the respondents who failed to answer the test correctly twice in a row.

Prior to the surveys, three focus groups (FGs) were conducted to explore the decision factors underlying consumer preferences for menstrual products and verify the DCE design in the surveys (Blamey et al., 2000; Louviere et al., 2000); FG participants were asked about the relevance of the choice set, confirming whether the attributes reflected their interest in selecting menstrual products and assessing the realism of the levels. Moreover, the FGs aimed to explore a comprehensive understanding of the topic, including social norms and insights beyond the quantifiable data of the DCE study. Consumers of menstrual products aged 18–49 in Japan, Indonesia, and France were recruited through snowball sampling, a survey method that relies on referrals from the initially sampled respondents (Sedgwick, 2013; Johnson, 2014). On June 12th, 2023, eight participants were recruited for the Indonesian FG, eight were recruited for the French FG on June 16, 2023, and five were recruited for the French FG on July 9, 2023. A participant size of 5–10 was the recommended choice for preference studies (Louviere et al., 2000). In this study, a female researcher presided over all the FGs through an online meeting platform and recorded them. Informed consent was obtained from all participants. Prior to the FG, questionnaires were distributed as supplementary tools as an additional means for participants to express their thoughts, experiences, and opinions.

Three versions of the questionnaire were prepared for the three groups: one for the control group and two for the two treatment groups. They were translated into Japanese, Bahasa, and French and were finalized by the authors, whose first language was one of the three. Sample questionnaires in English have been provided in the Supplementary material S1.

We recruited 6,027 respondents aged 18–49 via survey companies (n = 1,929 from Japan; n = 2,031 from Indonesia; n = 2,067 from France). Individuals who failed to answer a trap question were removed during recruitment to maintain data quality (Liu and Wronski, 2018). The survey for the French group was conducted using Cint¹ from September 20 to October 16, 2023; the survey for the Indonesian group was conducted using Populix² from August 26 to August 30, 2023; and the survey for the Japanese group was conducted using iBRIDGE³ from August 17 to August 18, 2023. The questionnaire contained two eligibility requirements: (1) they must be 18–49 years old, and (2) they must be consumers of menstrual products in Japan, Indonesia, or France. For DCE analysis, respondents in the treatment groups who failed to correctly answer the comprehension assessment were removed, the passing rates were 90.5–97.3% (Supplementary Tables S1, S2). Informed consent was obtained from all respondents after explaining the purpose of the study and their rights. Data used in the study is available in the Supplementary material S2.

Under random utility theory, we applied a conditional logit model to analyze the data obtained from DCE (Aizaki et al., 2014). While the mixed logit model, which is a more flexible model, is being increasingly adopted (McFadden and Train, 2000; Hensher et al., 2015), we did not use it because our choice design did not include the attributes to be tested for heterogeneity. Price, the only attribute that varied across the choices in our design, was not specified as a random parameter. The systematic component of the utility for respondent n for alternative i , V i n (Equation 1), can be expressed as

where ASC is an alternative-specific constant, β i is the main effect associated with price, and the last three terms are two-way interaction terms between A S C i and covariates reflecting respondents’ psychological scales, and γ i , 1 to γ i , 3 are the interaction effects (Hensher et al., 2015). The systematic component of utility for the “none of these” option was set to zero.

Based on the conditional logit model estimates, we computed the marginal willingness to pay (MWTP), and the Krinsky and Robb method was employed to compute the 95% confidence interval of the MWTP (Aizaki et al., 2014). Data were analyzed using statistical software R, version 4.3.1 (The R Foundation, Vienna, Austria).

A total of 6,027 respondents were recruited (1,929 from Japan, 2,031 from Indonesia, and 2,067 from France). Table 4 presents the respondents’ sociodemographic characteristics. While the age distributions of the Japanese and French respondents were similar to those of the population, the Indonesian respondents’ age distribution was not because of the limitations of the sampling method, which might have affected sample representativeness.

Figure 4 depicts a comparison of the psychological scales, MDS, innovation friendliness, and GCV. Cronbach’s alphas for all scales, except the MDS for Japanese and Indonesian respondents, were above 0.70, indicating the reliability of the scales (Bland and Altman, 1997; Tavakol and Dennick, 2011). Since the 95% confidence intervals of MDS for the Japanese (0.66, 0.71) and Indonesian respondents (0.67, 0.71) were 0.70, we considered them acceptable. While the Japanese respondents had a higher mean MDS (3.31) than the Indonesian (2.95) and French respondents (3.07), they had a lower mean innovation (2.96) and GCV (2.89) than the Indonesian (3.57, innovation-friendliness, 3.74 for GCV) and French respondents (3.49 for innovation, 3.61 for GCV). While the values for the Indonesian and French respondents were similar to those of the Japanese respondents, they differed significantly for all three scales. Detailed information, including confidence intervals, has been mentioned in Supplementary Figure S1.

Sanitary napkins are the most regularly used menstrual products in all countries, as shown in Figure 5. However, the reasons for this varied across countries (Supplementary Tables S4, S10, S16). While price and familiarity were common primary reasons for the respondents from all countries (>40%), functions (absorbency, leakage resistance, and comfort) were primary reasons (>40%) only for Indonesian and French respondents. Only the Indonesian respondents chose wide availability or accessibility (51%) as their primary reason. While the French respondents did not think convenience was the reason (19%), the Japanese and Indonesian respondents thought convenience was the primary reason (48 and 67%, respectively). Tampon use was the highest in France (18.9%) and the lowest in Indonesia (0.2%). The use of MC was limited in all countries but relatively higher in France than in the other two countries (3.2% of the French sample compared to 0.7% of the others). Comparing the reasons for choosing MC with those for the other two products, environmental consciousness was highly valued (38% for the Japanese, 86% for the Indonesian, and 52% for the French respondents). Similar to the reasons for using other products, price, leakage resistance, comfort, and convenience were also considered reasons. However, unlike with sanitary napkins, familiarity was not a reason for this finding. Additionally, a portion (4.7%) of French respondents used other menstrual products, such as menstrual panties and reusable towels.

Figure 6 illustrates respondents’ familiarity with MC. Most respondents knew what MCs are to some extent (75.6% of the Japanese respondents to 91.7% of the Indonesian respondents). Japanese respondents demonstrated relatively limited familiarity compared to the other two countries, with 13% indicating moderate or good familiarity. Indonesian respondents were relatively familiar with MC. French respondents fell between these two.

Figure 7 illustrates the perceived barriers to MC adoption. While “Unfamiliarity and limited knowledge” was the most significant barrier for the Japanese (67%) and French respondents (46%), “Concern about comfort” (65%) was the one for the Indonesian respondents. “Unfamiliarity and limited knowledge” (67%) relatively stood out for the Japanese respondents compared to other barriers. On the contrary, while “Unfamiliarity and limited knowledge” was also a concern for the French respondents (46%), it was less than those of the Japanese and Indonesian respondents and as equally critical as “Concern about leakage” (46%) and “Hygiene and maintenance” (43%). In addition to “Unfamiliarity and limited knowledge,” “Concern about leakage” and “Hygiene and maintenance” were common concerns in the three countries (>30%). The Indonesian respondents were concerned more about MC in most aspects than the Japanese and French respondents; notably, “Impractical” (35%), “Limited availability or accessibility” (30%), and “Cultural or social stigma surrounding MCs” (15%), were roughly more than double of those of the Japanese and French respondents.

Figure 8 illustrates the respondents’ willingness to adopt MC if it is free. Free MC is certainly an effective measure but is not equally effective across countries. Most Indonesian and French respondents expressed willingness to adopt free MC (63.9 and 61.1%, respectively), whereas Japanese respondents exhibited a lower level of willingness (27.4%).

Table 5 presents the model estimates without the interaction terms. All coefficients of menstrual products across Japanese and French respondents were statistically significant. The price attribute consistently demonstrated a negative coefficient, indicating that an increase in price is associated with a decrease in the probability of choosing a product, aligning with the economic theory of consumer behavior (Louviere et al., 2000). However, the coefficients of tampons were not statistically significant for the Indonesian respondents, except for the price coefficient of the control group.

Figure 9 lists the MWTP values for menstrual products across the control and treatment groups by product type and country. The respondents in treatment group 2 (the group that received information on the cost-effectiveness of MC) in all countries showed a statistically significantly higher MWTP for MCs than the control and treatment group 1 (the group that received information on the impact of menstrual products on human health and the environment). Furthermore, no statistically significant difference was observed between the control and treatment group 1 regarding the MWTP for MCs. No statistically significant differences were observed in the MWTP for sanitary napkins and tampons across the groups of Japanese and French respondents. However, the MWTP for sanitary napkins for treatment group 2 of Indonesian respondents was significantly lower than that of the other two groups.

Table 6 presents the conditional logit model estimates with the interaction terms. The estimates are for control groups to focus on the influence of psychological factors (i.e., MDS, innovation friendliness, and GCV). The coefficient of the interaction term in the estimates (e.g., ASC1: MDS) explains how a psychological factor (MDS) affects the respondents’ MWTP for a menstrual product (sanitary napkins). While the Japanese respondents with high MDS preferred tampons less compared to the overall respondents, Indonesian and French respondents with high MDS preferred sanitary napkins and tampons, or all of them. Respondents with high innovation friendliness in all countries preferred tampons and MCs more than the overall respondents. Japanese respondents with high innovation friendliness also preferred sanitary napkins. The GCV demonstrated differences only in French respondents; French respondents with a high GCV preferred MCs more and tampons less than the French respondents overall.

Sanitary napkins were the predominant choice across Japan (92.8%), Indonesia (98.7%), and France (73.1%, Figure 5). Our study revealed commonalities and differences in the reasons for choosing sanitary napkins across countries (Supplementary Tables S4, S10, S16). While Japanese respondents focused on prices, familiarity, and convenience, Indonesian and French respondents also cared about functions (absorbency, leakage resistance, and comfortability). This may mean that function is not a significant issue in the quality of menstrual products in the Japanese market or for Japanese consumers. For example, previous studies revealed that price is the main consideration for Japanese consumers (Tokunaka et al., 2018; Kigawa, 2023; Nakao et al., 2023). The availability of products was the primary reason for Indonesian respondents, implying a difference in the markets of Indonesia, Japan, and France. For example, the low use of tampons among Indonesian respondents can be directly attributed to the fact that tampons are mostly imported and less accessible, leading to a clear preference for sanitary napkins (Martin and Stuart, 2017; VanLeeuwen and Torondel, 2018).This aligns with the study by VanLeeuwen and Torondel (2018), who noted the high accessibility and affordability of sanitary napkins as pivotal factors in their widespread use. In France, while sanitary napkins were predominantly used, MCs were more widespread. These results coincide with those of a survey conducted in France (Petruzzi, 2022). Notably, environmental consciousness was highly valued compared to other products by the respondents, indicating that environmentally conscious consumers generally choose MCs. Therefore, the widespread use of MCs among French respondents may represent French consumer openness to environmentally friendly products (Fusaro, 2016; Trouillard and Dodman, 2020). The GCV was high for the French respondents. Although the GCV was also high for Indonesian respondents, there were other reasons for not choosing MCs, as discussed below. Price, leakage resistance, and comfort were also commonly chosen, indicating that consumers using MCs knew its cost-effectiveness and functions. Hence, lack of knowledge could be one of the primary reasons for not using MCs.

Overall, while regular MCs use was limited in all countries, the respondents were aware about MCs to some extent, highlighting a discrepancy between knowledge and actual use. However, some differences were observed. For example, despite the relatively high familiarity among Indonesian respondents, MCs usage was observed to be low. This aligns with the findings of Shelby and Puspitasari (2022) which suggests that familiarity alone does not ensure adoption, particularly in Indonesia. In Japan, the low knowledge level about MCs might be due to a lack of open dialogue about menstruation, as highlighted by Itaya et al. (2022). This absence of open dialogue hinders the understanding and acceptance of alternative menstrual products, potentially limiting informed choices and perpetuating reliance on conventional options (Peter and Abhitha, 2021).

Although the respondents in all countries were aware about MCs to some extent, “unfamiliarity and limited knowledge” remained relatively critical barriers to the adoption of MCs in all countries, indicating the importance of information strategies (Figure 7). In particular, “unfamiliarity and limited knowledge” stood out among others in the Japanese respondents. Singh et al. (2022) argued that non-acceptability issues stem from a deficiency in the awareness and understanding of menstrual products. Pokhrel et al. (2021) claimed that a detailed understanding of their use, upkeep, and associated hygiene practices may not be widespread. Moreover, Ahuja and Singh (2023b) have shown that adequate knowledge about sustainable menstrual products correlates with positive perception, thereby increasing their acceptability. This lack of detailed knowledge could explain why despite high awareness, the actual utilization of MCs remained relatively low. Additionally, “concerns regarding leakage” hindered adoption across all countries, with many women favoring the perceived reliability of sanitary napkins and tampons for leak prevention (van Eijk et al., 2019; Gharacheh et al., 2021).

In comparison, the Indonesian respondents raised more barriers in most aspects than the Japanese and French respondents, notably “Impractical” (35%), “Limited availability or accessibility” (30%), and “Cultural or social stigma surrounding MCs” (15%). This reluctance may stem from Indonesia’s conservative cultural context, where intravaginal insertion required by MCs challenges norms related to fertility and virginity (Harris, 2020; Pokhrel et al., 2021). Several studies in Indonesia have highlighted how religious and social norms can deter the adoption of MCs and similar products (Harris, 2020; Sato et al., 2021). As the world’s second-largest Muslim population, Indonesian sociocultural practices are significantly shaped by Islamic perspectives (Tempo.co, 2024). Within this community, virginity (often symbolized by an intact hymen) is esteemed as a marker of sexual purity and familial honor (Rashid and Michaud, 2000; Shalhoub-Kevorkian, 2005).

This has been observed in other developing countries such as India (Meenakshi, 2020). Although some studies claim the importance of stigma and shame in developed countries (Grose and Grabe, 2014), Japanese and French respondents did not show this tendency. Moreover, the limited availability of MC in Indonesia is a significant barrier to their adoption. Consumers prefer easily accessible and familiar menstrual products, often opting for affordable and practical disposable sanitary napkins (Philipp, 2022; Kamira and Rizkalla, 2023). Furthermore, the perception of “Impractical” indicates that a proportion of Indonesian respondents found MCs to be challenging to incorporate into their menstrual hygiene routines. This perception of impracticality may encompass various factors, including difficulties in use, inconvenience, compatibility with lifestyle, potential learning curve, and maintenance requirements, which align with the findings reported by Stewart et al. (2009). Further illustrating these practical challenges, participants in the FG expressed apprehension regarding the proper technique for washing and sterilizing the cups, particularly given the time investment necessary. Despite being aware of the environmental benefits, the trade-off between the perceived time or effort and the sustainability advantages did not favor the adoption of menstrual cups. These differences in perceived barriers highlight the need for tailored promotional strategies to encourage MC adoption in diverse cultural contexts.

Across all countries, the MWTP for the treatment group with information about the cost-effectiveness of MCs was significantly higher than that of the control group; those for the treatment group with information on human health and the environmental impact of menstrual products were not statistically different from the control group (Figure 9). This suggests that cost-effectiveness is a compelling message for encouraging MC adoption, whereas health and environmental impacts are not as persuasive. This also implies that the cost-effectiveness of MCs is not perceived well. Consumers may focus on the upfront price per piece, which is shown in the price tag, rather than the long-term per-use cost, which is crucial when comparing MCs to disposable alternatives like sanitary napkins and tampons. The relatively low importance of the cost of MCs as a barrier seems contradictory (Figure 7). A recent French survey revealed that only 6.6% chose cost as the reason for not using MCs (Parent et al., 2022). However, this means that respondents had little sense of price in the first place. The insignificance of human health and environmental impacts was not expected, given that environmental awareness is a strong predictor of green purchases (Testa et al., 2020), and positive health perceptions favor sustainable menstrual products (Peberdy et al., 2019; Moon et al., 2020; Ahuja and Singh, 2023a). Gölbaşı Koç et al. (2023) also noted that knowledge of the environmental effects of single-use menstrual products might raise the demand for reusable options. In summary, given the inherent importance of pricing considerations for environmentally friendly and sustainable products, our results show that providing consumers with tangible data on the long-term cost-effectiveness of MCs can raise awareness and enhance the perceived value of these sustainable products.

While previous studies have indicated the economic advantages of MCs (Burt et al., 2016; Hyttel et al., 2017; Popović et al., 2019; Pokhrel et al., 2021; Khorsand et al., 2023), interestingly, prior studies of adopting sustainable menstrual products have often overlooked the cost-related aspect, focusing instead on other factors such as comfort, health risks, and psychological factors. For example, a systematic review and meta-analysis of MC uses identified barriers to adopting MC mostly about usability such as “Difficult to remove” and “Uncomfortable to wear” (van Eijk et al., 2019). Gharacheh et al. (2021) emphasized product functions and health risks, leaving economic analysis largely unexplored. Valentin and Hechanova (2023) investigated consumers’ intentions to use MCs by applying an extended theory of planned behavior. However, previous studies asserted that affordability is a decisive factor in the purchase of sustainable products (Martinho et al., 2015; Kushwah et al., 2019; Sultan et al., 2021). Consumers often undervalue the higher production costs of environmentally friendly products (Bissinger, 2019) while equating lower-priced goods with better value (Ghali and Toukabri, 2019). Providing cost-effectiveness information led to an observed increase in the MWTP for MCs, which is reasonable as respondents who were informed about the cost per use of menstrual products recognized that MCs represent a more economical choice over time than disposable menstrual products.

Notably, the MWTP for sanitary napkins in Indonesian respondents with cost-effectiveness information about MCs was significantly lower than that of the rest, those patterns were not observed in Japanese and French respondents. A possible explanation is that Indonesian consumers, potentially because of varying economic conditions, might exhibit greater price sensitivity, thus showing heightened responsiveness to information that underscores cost savings. Our study showed that the Indonesian respondents raised the prices as one of the primary reasons for adopting sanitary napkins (60%) and MCs (46%), as shown in the Supplementary Tables S21–S23 in SM1. Aligning with this observation, Boobalan and Nachimuthu (2020) highlight that consumer in developing economies tend to prioritize cost as a decision-making factor more than those in developed economies.

The Japanese respondents with high MDS preferred tampons less, indicating a reduced preference for tampons, possibly an indication of their inclination away from menstrual products that require internal use. MC requiring internal use was not significant, probably because they did not know about it in the first place. In contrast, Indonesian respondents with high MDS preferred tampons and sanitary napkins. More knowledge, particularly concerning to MCs (Figure 7), could explain their relative preference for MCs. Interestingly, French respondents with high MDS scores preferred all available options. A possible explanation is that they preferred to choose these three products rather than buying nothing (i.e., opt-out option) to better manage menstruation. Notably, the MCs might be preferred by the respondents with high MDS because of their perception of lower health risks posed by them (Parent et al., 2022); 66% of the survey respondents chose “Less harmful/dangerous to health” as a reason for using MCs. The French FG in our study also showed sensitivity to health risks.

Respondents with high innovation friendliness in all countries preferred tampons and MCs over sanitary napkins. Because people with high innovation friendliness are more receptive to experimenting with and adopting novel products, this inclination can be attributed to their attraction to the novelty and unfamiliar nature of these menstrual products. Notably, despite their high innovation friendliness, Japanese respondents also showed a significant preference for sanitary napkins, potentially due to their high ‘Uncertainty Avoidance’ (Hofstede Insights, 2019) and extensive marketing innovations within this product, dampening their incentive to explore unfamiliar products. Although no objective data were available, we observed various TV commercials appealing to their innovative menstrual products.

We observed a significant relationship between GCV and menstrual product choice among French respondents, with those exhibiting a high GCV showing a pronounced preference for MCs and a negative preference for tampons. The lack of knowledge and experience in MCs among Japanese and Indonesian respondents with high GCV (Figures 5, 6) could explain why people with high GCV did not show distinctive preferences for MCs. They did not know much about their environmental benefits. More French respondents used MCs regularly (Figure 5).

Disseminating cost-effective information is a promising measure for promoting sustainable menstrual products for any type of consumer in any country, given that it was significant across all three countries in our study. It can be disseminated through various paths such as health professionals, information campaigns, companies, and media (Parent et al., 2022). Installing informational displays adjacent to MCs may be very effective; hence, at the point of purchase, the strategy is called simplification and framing, one of the nudges that can change people’s behavior without overt coercion (Uehara et al., 2023b). Because the target is price, adding per-use cost information to the price tag can be both convenient and effective. A recent study adding the true costs comprising negative social and environmental costs of a product demonstrated its effectiveness as a nudge (Wilken et al., 2024). In countries such as Japan and France, where digital price tags, including per-unit costs, are common, the additional cost of the strategy may not be prohibitive. Conversely, in countries like Indonesia, where digital price tags are less common, manual pop-ups can be used by stores.

While some strategies can be applied to most countries (e.g., cost-effectiveness information), it is also important to tailor strategies reflecting the differences in consumers and markets in each country, as our study showed variations in consumer characteristics and preferences across the three countries. For example, strategies to enhance awareness and provide comprehensive knowledge about their benefits are particularly important for Japanese consumers, as the knowledge and experience of MCs are limited among Japanese respondents. Influencer marketing, which is anticipated to reach an expenditure of 74.1 billion JPY by 2023, offers a promising platform for educational initiatives (Statista, 2023). Influencers and key opinion leaders (KOLs) can effectively promote sustainable consumption (Tran and Uehara, 2023). Since psychological hesitation and apprehension about the initial use of MCs are key among Japanese consumers, as found in our study, which is also in line with a previous study (Itaya et al., 2022), KOLs can play a critical role in demystifying MCs and addressing common concerns through trusted endorsements. In line with this, recent studies have shown that education and mass media exposure significantly increase the likelihood of adopting menstrual cups (Babbar and Garikipati, 2023; Balkan and Koyucu, 2024). Furthermore, educating about menstrual cups aligns with Sustainable Development Goal (SDG) 5 by reducing the stigma around menstruation and fostering a more inclusive and equal society. Although such promotional strategies are equally important in Indonesia, it is essential to synchronize MC marketing with improvements in distribution, owing to the significant role of product availability and accessibility in shaping consumer choices. Strategic partnerships with Indonesian retail entities could extend MC’s reach while supporting the government’s initiative to fortify micro, small, and medium enterprises (MSMEs) through the promotion of locally produced MCs, thus enhancing both access and affordability (Coordinator of the Ministry of Economic Affairs of the Republic of Indonesia, 2022). Furthermore, integrating culturally tailored campaigns such as myth-busting initiatives and ensuring halal certification resonates with Indonesia’s socio-religious context, thereby enhancing the likelihood of widespread adoption (Septiani and Ridlwan, 2020). In the French market, comfort is highly valued, with a significant proportion of respondents (56%) ranking comfort as the primary factor in choosing menstrual products, whereas 46% cited comfort concerns as a barrier in adopting MCs. Hence, MCs marketing should highlight its ease of use and adaptability to active lifestyles. Moreover, detailed and clear communication about a product’s environmental benefits and waste reduction is essential to address the preferences for reliable information, as identified by Herbes et al. (2020). Additionally, assurances of quality and safety, supported by medical endorsements and third-party reviews, are vital to meet the health-oriented expectations of French consumers, who often depend on healthcare professional guidance when selecting menstrual products as raised in the French FG; a study also revealed that 91.2% of the respondents chose health professionals as desired sources of information on menstrual products (Parent et al., 2022).

The provision of free MCs is a promising approach. Although the respondents’ use of MCs ranged from 0.70 to 3.2%, the willingness to adopt free MCs among the respondents who did not regularly use them ranged from 27.4 to 63.9%. In addition to its effectiveness in promoting a sustainable solution, free provisioning could enhance menstrual health management, which eventually address period poverty globally. While period poverty has often been discussed in low- and middle-income countries (Critchley et al., 2020; Rossouw and Ross, 2021), developed countries are no exception. A survey with Japanese young women found that 35.9% of them had been hesitant to or were unable to buy menstrual products for economic reasons (Plan International Japan, 2021). A survey with Japanese junior and high school male and female students revealed that 40.6% of them knew or had heard of period poverty (Nishinomiya City Center for Gender Equality, 2021). As of 2022, the Japanese government and municipalities have initiated programs, such as providing free sanitary napkins (Gender Equality Bureau Cabinet Office, 2022). Similarly, in France, 30% of young women aged between 18 and 24 struggle to afford menstrual products (Nilsson-Julien, 2023). In response, the French government made reusable menstrual products free for people under 26 years of age (Service Public.fr, 2023). Although the Japanese respondents’ willingness was lower (27.4%), the adoption of reusable menstrual products, such as MCs, can be improved through their understanding and experience. They had limited knowledge compared with Indonesian and French consumers, which was a barrier to adoption (Figures 6, 7). Their impression of them also included limited knowledge and being afraid of using them (e.g., “I am worried because I have never used it before,” “Afraid”). Governments, including those in developed countries, have taken the initiative to provide free-period products to their citizens (Rodriguez, 2021). For instance, Scotland became the first country to offer free menstrual products to all students in schools, colleges, and universities, as part of its commitment to eradicate poverty. However, the predominant focus on disposable items, apart from a few exceptions such as France, highlights the urgent need to pivot towards sustainable alternatives. This not only provides a long-term solution for period poverty but also contributes to environmental sustainability. Although most initiatives have targeted certain populations, such as youth and college students, they offer good opportunities to learn and experience using MCs. Hence, this exposure could cultivate a preference for MCs among individuals once they transition to purchasing their menstrual products. Conversely, free distribution of MCs, although well-intended, might inadvertently restrict choice by presenting MCs as the sole viable option for individuals facing financial difficulties. This could potentially create a dynamic where economic necessity, rather than personal preference, dictates the uptake of menstrual products, questioning the ethics of choice and reinforcing existing social hierarchies. To truly address period poverty, these initiatives must ensure that the introduction of free MCs is accompanied by educational efforts to inform users about their benefits and maintenance requirements, highlighting the importance of personal choice and minimizing any potential stigma associated with their use (Michael et al., 2020; Schmitt et al., 2022; James et al., 2024).