Introduction

Social media use is increasing among all demographics worldwide [1], raising questions of its impact on the public’s understanding and corresponding decision-making related to the health sciences [2,3]. Successfully navigating these online spaces requires high levels of digital health literacy, which relate to one’s ability, capacity, as well as availability of resources to find and evaluate health-related discourse that leads to positive health outcomes [4]. Over the past decade, a growing awareness of online health misinformation correlates with cases of decreased vaccination rates [5], growth of fad diets and unproven biohacking trends [6–8], and a surge in scientifically-unsupported alternative therapies and products [9,10]. Leading academic and public health bodies have identified misinformation as an urgent problem requiring concerted attention [2,11]. It is a problem with heightened relevance in the context of cancer [12–14], which is a leading cause of death worldwide [15]. While cancer causes can be most attributable to family history, genetics, and aging, numerous individual risk-prevention measures can be taken by those fortunate to control lifestyle factors [16]. Individual cancer-risk prevention measures should be informed by accurate science and not influenced by myths, influencer anecdotes, misconceptions, ineffective products, deceptive marketing, or inaccuracies trending on social media or in the public domain [17]. Widespread public prevention measures are also vitally important in the context of public health care systems, where cancer treatments use considerable budgetary funds [18]. It remains essential to counter misinformation so that it does not lead the population towards scientifically unsupported cancer-related activities, products, and therapies or away from accessible evidence-supported prevention measures that can maintain health and save lives.

Skin cancer is primarily caused by exposure to ultraviolet radiation (UV) and consists of melanoma and non melanoma (known as keratinocyte cancer), which is made up of two main subtypes: basil cell carcinoma (BCC), and squamous cell carcinoma (SCC)) [19]. Melanoma is the least common skin cancer type but is the most serious and aggressive, with high potential to spread to other areas of the body, including organs [20]. The risk of melanoma principally increases following multiple high-intensity UV exposures (e.g., sunburns), with the common adage being that five or more sunburns doubles one’s risk [21]. Sunburns during childhood or young adulthood also substantially increases the risk of melanoma as does frequent tanning bed use among younger adults [22]. BCC is the most common form of skin cancer but rarely spreads to other parts of the body. BCC and SCC are both more common but substantially less serious and fatal than melanoma, and typically develop later in life following prolonged but not necessarily high-intensity UV exposure [19]. Advanced SCC, however, can spread to other areas of the body resulting in more serious effects, including death [22]. Like melanoma, intense UV radiation exposures (e.g., sunburns), also can increase the BCC and SCC risk [23]. Broadly, skin cancer risk increases among those with lighter/fairer skin and those with a family history of skin cancer [24]. UV radiation exposure is now a well documented occupational hazard for all professions working outdoors for long periods of time [25].

Skin cancers have high, and growing incidence rates in numerous regions, with “age-standardized incidence rate (ASIR) rising globally (Estimated Annual Percentage Change, EAPC = 1.94%) from 1990 to 2021,” and with notably high ASIR recorded in high-income North America [26]. This is despite the fact that preventative measures are generally affordable and accessible. Avoiding extensive and prolonged UV radiation exposure from the sun or tanning beds can be achieved in a relatively straightforward manner by using protective clothing, applying proper sunscreen/sunblock [27], and avoiding harmful activities such as tanning [28]. In 2024, numerous health bodies observed sunscreen misinformation trending in online public discourse, which included sentiments that sunscreen use was either toxic – and even cancer-causing – or harmfully preventing the benefits of sun exposure (i.e., limiting absorption of Vitamin D). These observed sentiments, in cases expressed by popular celebrities and online influencers, included ideas, for example, that ancestors from generations past spent considerable time in the sun without sunscreen and benefited from such exposure [29]. While not all sunscreen critique is categorically unjustified – in 2021 certain products were recalled for having detectable levels of benzene, an established cancer-causing carcinogen [30,31]– this concern pertained only to a few specific products at a particular time and not broadly to either all non-mineral-based sunscreens or to sunscreen generally as a sun protection tool.

Of critical importance to sunscreen misinformation, there are currently no scientific indications that any ingredient widely used in “chemical” sunscreens (e.g., Oxybenzone) is harmful to one’s health [32,33]. Consumers may prefer a mineral or “natural” sunscreen that blocks UV rays versus a “chemical” sunscreen that absorbs and deactivates rays, but both options are considered safe, and in no circumstance is not using sunscreen a safer option than using a “chemical” product during sun exposure. Rather than an issue of harmful properties, a more pertinent sunscreen issue may be related to SPF accuracy in product labelling as revealed in testing by CHOICE, an Australia consumer advocacy group [34].

Additional concerns have raised about microplastics in sunscreen. Microplastic concerns are not baseless as science continues to assess how microplastic absorption may have negative effects on human health and the environment [e.g., 35]. In the sunscreen context, however, there is no heightened microplastic exposure concern compared to, for example, when humans ingest microplastics via plastic food and drink storage containers [36] or inhale airborne microplastic particles (e.g., synthetic fibres, rubbers, etc. [37]) in indoor and outdoor environments. Public health notices, in response to trending online discourse, observed the possibility of considerable sunscreen related misinformation on TikTok [38–41], one of the world’s most used social media platforms, especially among youth [42]. The observed trending of sunscreen misinformation coincides with a growing body of research showing problematic portrayals of sun protection online, including with intersection of conspiratorial thinking [43–45]. Survey research has similarly found some knowledge accuracy issues related to sun protection and skin cancer [17,46], in particular among younger demographics [47]. Given these concerns, we conducted a systematic assessment of the presence and interaction levels of sunscreen misinformation across the most viewed and engaged with sunscreen content on TikTok. In addition to ascertaining the presence of harmful misinformation, the project mapped out key characteristics in the sunscreen TikTok discourse, including how it was portrayed and engaged with by TikTok audiences.

Materials and methods

As this research solely analyzed publicly available social media data, ethical review was not required.

Results

During coding, 155 of the 1126 TikTok videos (TikToks) were either inaccessible (i.e., non-functioning URLS) or non-English, resulting in a total data set of (N = 971) TikToks, which had amassed over 2.4 billion views, 3.3 million shares, 94.8 million likes, and 728 thousand comments (Table 1). TikToks commonly presented or discussed specific sunscreens and/or sunscreen brands (n = 662, 68.2%), and often promoted specific products (n = 599, 61.7%), in cases by comparing or ranking products (n = 128, 13.2%). Several TikToks included specific purchasing options, such as by offering discount codes in video content or captions (n = 112, 11.5%). While women were present in the majority of TikToks (n = 738, 76.0%), men also had a substantial presence (n = 144, 14.8%). Medical professionals, most noticeably dermatologists, had a presence in approximately 10% of all TikToks, appearing in videos (n = 81, 8.34%) or being referred to by those in videos (n = 15, 1.3%). The TikTok producers were overall diverse, consisting primarily of White (n = 411, 42.3%), Asian (n = 260, 26.8%), and Black (n = 138, 14.2%) peoples (Table 1).

Download:

• PNG
  larger image
• TIFF
  original image

Table 1. Content, producer, and engagement characteristics of popular sunscreen related TikToks (N = 971).

https://doi.org/10.1371/journal.pdig.0001440.t001

Audience interactions with promotion and health critique TikToks

The four most relevant audience interactions with TikToks are views, likes, shares, and comments. Comparing the mean difference between TikTok with only sunscreen promotion (OP), sunscreen promotion and critique (P&C), and only sunscreen critique (OC) revealed a trend of greater audience engagement in TikToks with critique across the respective mean averages of all audience interactions (Table 2 and Fig 1). The difference in views did not produce a significant Kruskal-Wallis score across the different TikToks (p = 0.182). Following a significant Kruskal-Wallis test for likes, shares, and comments, a Dunn’s post-hoc test with Bonferroni adjustments produced significant differences between OP and OC TikToks for likes (p = 0.0069), shares (p = 0.0028), and comments (p = 0.0012) (Table 2). Thus, TikToks that solely contain sunscreen critique present significant greater audience interaction in terms of likes, shares, and comments in comparison to TikToks that only promote sunscreen. Further, TikToks that include sunscreen promotion and critique also present significantly higher numbers of shares and comments – but not likes – in comparison with TikToks that exclusively promote sunscreen (Table 2 and Fig 1). However, when examining the difference between OC and P&C TikToks for shares and comments, the audience interaction metrics are not significantly different (Table 2). Overall, this suggests that TikToks which include a sunscreen critique, either as the sole focus of the TikTok or in combination with sunscreen promotion, is a driver of increased audience interaction. When critique appears in videos, regardless of promotion, there is an observed and significant boost in audience engagement (Table 2).

Download:

• PNG
  larger image
• TIFF
  original image

Table 2. Engagement metrics by observed sunscreen content.

https://doi.org/10.1371/journal.pdig.0001440.t002

Download:

• PNG
  larger image
• TIFF
  original image

Fig 1. Statistically significant differences in mean likes, shares and comments between all TikToks (n = 971), only Tiktoks with sunscreen promotion (n = 801), Titkoks with sunscreen promotion and critique (n = 42), and Tiktoks with only critique (n = 16).

https://doi.org/10.1371/journal.pdig.0001440.g001

Hashtag analysis

A total of 8,104 hashtags were used in the 971 TikToks, with an average of 8.3 hashtags per TikTok. Of the 8,104 hashtags used, 3,106 were unique. The five hashtags chosen for TikTok downloads were among the most used, with the remaining popular hashtags focused on skincare (e.g., #skincare, #skincareroutine) and general popularity (e.g., #fyp) (Fig 2). This demonstrates how sunscreen content was highly intertwined with general skin and skincare content on TikTok.

Download:

• PNG
  larger image
• TIFF
  original image

Fig 2. Most used hashtags in Tiktoks (N = 971) with blue bars representing hashtags selected for data collection.

https://doi.org/10.1371/journal.pdig.0001440.g002

Discussion

This project, contrary to the findings from other research [32], provides strong evidence that popular sunscreen-related TikTok content is not “rife” with sunscreen misinformation that portrays sunscreen as either harmful to one’s health or preventative of sun exposure benefits. Of the 971 most popular and engaged with sunscreen related TikToks, we found only 58 (6.0%) critiquing sunscreen on these grounds. Further, of these 58 videos with critique, the majority (72%) also included sunscreen promotion, leaving only 16 TikToks (1.6%) which critiqued sunscreen without any promotion, thus categorically dissuading its use. This project therefore corroborates findings from earlier media research on sunscreen in the popular press and on X (formerly Twitter), which similarly found a very low, but not completely absent, presence of misinformation [54,55].

However, while sunscreen misinformation constituted only a small proportion of popular sunscreen TikTok content, this small number of TikToks generated substantial and significant levels of audience engagement. Indeed, the 16 (1.6%) TikToks presenting a categorical critique of sunscreen had a significantly higher mean number of shares and likes compared with promotional videos (Table 2). TikToks with critique also generated a considerably greater mean number of comments (Table 2). Analyzing comments on the TikToks was beyond the scope of this project but it would be highly valuable for future research to assess the extent to which TikTok commentary supported or critiqued misleading and inaccurate sunscreen ideas. It may also be valuable to assess whether other TikTok characteristics such as TikTok length could be an influential factor on audience engagement.

Sunscreen misinformation on TikTok therefore constitutes an area of concern not for the total sum of overarching influence in terms of content production but rather in how strongly some sunscreen misinformation ideas resonated among particular audiences. This demonstration of sunscreen misinformation on social media aligns with a growing understanding of the misinformation problem as one that can contain small but highly influential numbers of content producers, whose shock-provoking and “sticky” content can generate considerably and disproportionately greater attention or interaction among some viewers [56,57]. Indeed, misleading and contrarian ideas, for example, that sunscreen is either useless or harmful, incorporates novelty, shock value, and conspiratorial components that trigger emotions and leads to increased viral potential, especially among groups or online communities with a propensity to be intrigued by this type of content [58]. Repeated exposures to this sort of misinformation not only enhances the potential for online viral spreads but increases perceptions of accuracy among all audiences [59]. Thus, counter to critiques of the misinformation problem severity [60], this study adds to the evidence that misinformation does not have to be “rife” to be of potential concern [61]. It is therefore a sound response from public health agencies to immediately and swiftly sound the alarm of an observed misinformation trend rather than idly permit the problematic discourse to foster. At the same time, it remains imperative for public health agencies, wherever possible to increase surveillance capacity to not only observe emerging trends in problematic information but to accurately discern the extent of the burgeoning issues.

Further adding to the potential concern of sun protection content on TikTok is one, evidence of misinformation related to skin cancer, where pro-tanning messages circulate [62], but also, as evident in this research, that sunscreen promotion on the platform is both highly commercialized and highly focused on aesthetics rather than explicit health benefits. Indeed, 62% of all TikToks promoted specific products, 15% promoted sunscreen for acne-related benefits, and 12% promoted sunscreen for reducing the effects of aging. Only 6% of the TikToks explicitly mentioned the benefits of reducing cancer risks. It is worth questioning whether such a prominent focus on skin aesthetics might exacerbate the gender divide around promoting sunscreen’s health benefits [63].

It is not conclusive from this study whether the health benefits of sunscreen are implicitly communicated and collectively understood by TikTokers. For public health, on one hand, the almost unanimous promotion of sunscreen should be celebrated, especially seeing as the promotion was carried out by a diverse body of TikTokers including a not-negligible presence of male content creators (14.8%). On the other hand, this portrayal represents a somewhat missed opportunity to communicate the important science of sunscreen’s vital health benefits. It is a growing challenge for online science communication and initiatives to bolster digital health literacy to compete with content that can easily leverage the advertising power of industry brands and products [64]. It is a challenge requiring ongoing and creative approaches to online discourse that can reach and influence audiences with important health messages and information evaluation strategies needed for positive health outcomes.

Supporting information

Acknowledgments

The authors acknowledge valuable coding contributions from Sophie Sigfstead and administrative assistance from Robyn Hyde-Lay.