The rise of influencers

The global influencer market has more than tripled since 2020¹, reflecting both the commercialisation of influence and the growing trust audiences place in online content creators. As of February 2025, 54.8 million people were reported to use social media in the UK, representing 79% of the population². This creates a conducive environment for influencers to shape attitudes and behaviours around health. 

Health-related content occupies substantial space online. On Instagram alone, hashtags such as #healthy, #healthylifestyle and #healthyfood have been used hundreds of millions of times, reflecting widespread interest in health, diet and wellbeing themes. Influencers exist across every niche possible, and health influencers can vary from healthcare professionals and patient advocates to fitness trainers, wellness coaches and self-appointed experts.

At the same time, it is becoming increasingly common to use social media to seek health-related information. A 2025 survey by the Edelman Trust Institute found that 33% of Gen Z and early Millennial respondents said they have let an influencer with no medical training influence their health decisions, compared with just 9% of those aged over 55³.

An overview of positive impacts

Social media influencers have the capacity to reach vast audiences, shape social norms, and impact health-related intentions and behaviours. This can be particularly beneficial for democratising health information by making it accessible, relatable and engaging. This is especially valuable for initiating conversations around historically stigmatised or under-researched topics. Social media can even offer a source of connection and support during health challenges. Many patient influencers, for example, share personal experiences of living with an illness. These can resonate with audiences who live with the same condition, providing a valuable sense of belonging and community.

Promoting healthy lifestyles

Through sharing inspiring, accessible content centred around health themes, influencers may contribute to the adoption of healthy behaviours. A scoping review found that social media influencers may be able to positively impact their followers’ exercise intentions⁴. Further, the same review found that influencers can also successfully promote healthier eating habits. For both diet and exercise, findings suggest that an influencer may be more successful at promoting healthier diet and exercise habits when they foster parasocial relationships with their followers⁴. These findings indicate that influencers can have a tangible impact on lifestyle choices – especially when followers feel a sense of connection to the influencer. 

Amplification of public health campaigns

Research suggests that influencers can contribute to effectively amplifying evidence-based public health messaging. During the Covid-19 pandemic, a campaign promoted by news media and a social media influencer was associated with improvements in self-reported hygiene and physical distancing behaviours⁵. Similarly, a study in the UK found that when influencers shared their experiences of cervical screening, this positively impacted attitudes towards screening⁶. With attitude a significant predictor of screening attendance, this directly increased the intention to attend and indirectly increased screening attendance. These findings suggest that influencers can be effective for time-sensitive campaigns, or for reaching groups that may be hard to reach through traditional public health campaigns.

Community and peer support

Many influencers foster online communities that can provide emotional support, practical advice and a sense of belonging. The same is true for influencers in the health space. For individuals who feel unsupported by healthcare systems, online communities can create an empowering space that offers validation and encouragement to seek care. Social media can be a powerful tool for consolidating disease knowledge globally – some patient influencers credit social media with helping them reach a diagnosis, sometimes after long delays faced in healthcare systems⁷. Patient influencers may also in turn help their followers recognise symptoms, navigate healthcare systems, manage their condition, advocate for themselves, or simply offer a source of support^4,7.

An overview of negative impacts

Alongside benefits, there are risks associated with health influencers. Several reviews have shown that health information shared online can be false, misleading, biased or oversimplified⁸. A study conducted by researchers from Glasgow University found that eight times out of nine claims made about weight management by self-appointed wellness ‘experts’ were not trustworthy and evidence-based⁹. When meal suggestions from these creators were examined against the Public Health England calorie and traffic light criteria, no blogger met the criteria⁹. Most lacked qualifications, failed to provide disclaimers and presented opinions as facts⁹. The consequences of misinformation online can vary in their degree of impact – for example, vaccine misinformation could lead to more immediate harm, while more subtly inaccurate lifestyle advice could shape long-term dietary behaviours with cumulative health impacts.

Dietary behaviours

Research into influencer marketing of food has yielded mixed results. While some studies suggest influencers can contribute to people making healthier choices, the opposite has also been shown by research. A systematic review found that the promotion of unhealthy foods significantly increased children’s energy intake, while the promotion of vegetables was not found to impact consumption habits¹⁰. Another study showed that children’s log-watching frequency was associated with the consumption of unhealthy beverages years later¹¹. This is of particular concern in the UK context of rising childhood obesity, as well as more widely in light of growing evidence linking ultra-processed foods to poor health outcomes¹². 

Commercial biases and product promotion

Many influencers monetise their platforms through sponsored content and affiliate links to earn a commission on product purchases. In the health space, this can involve anything from exercise equipment to fitness training applications and supplements. In a German study, researchers found that dietary supplements were often promoted by influencers on social media without sufficient discussion of risks and often exceeding recommended safe doses¹³. Another area of product promotion with potential health consequences is in the realm of medical tests. Research suggests that influencer promotion of medical tests often emphasises their benefits while failing to mention potential harms, which could lead to overdiagnosis and consequently place a strain on healthcare systems¹⁴. In more extreme cases, influencers have been associated with normalising access to products like anabolic steroids and performance-enhancing drugs which have demonstrable negative health impacts¹⁵. 

Body image and mental health

Beyond the promotion of products and behaviours, influencers may also contribute to social norms through the promotion of certain lifestyles or aesthetic ideals. Research has shown that exposure to idealised influencer body imagery is associated with negative effects on body image satisfaction and mood¹⁰. In turn, this may impact food choices among young adults – including dieting or food restriction, overeating, and choosing healthy foods¹⁶. This exemplifies the ways in which social media influencers can indirectly impact health. While the promotion of health-related behaviours or products can be easier to identify and control, mitigating harm from the indirect consequences of influencers may prove much more challenging.

The importance of credibility

As more people are turning to social media for health information, the credibility of influencers becomes an important determinant of impact. Existing research suggests that credibility can be multi-faceted. Factors commonly associated with perceived credibility of influencers include trustworthiness, expertise and perceived similarity ^17,18,19. Trustworthiness and expertise have been shown to be associated with the intention to engage in physical activity, while attractiveness often has no significant effect^17,18. Indeed, influencers are often seen as opinion leaders and experts in their field, garnering trust and seen as operating independent of institutional constraints²⁰.

Due to the sheer amount of information and health information online, it can prove overwhelming to discern which sources to trust. To navigate these platforms, heuristics such as bandwagon heuristics can come into play, whereby for example a higher number of likes can be associated with higher perceived credibility¹⁹. Algorithms tend to favour sensationalised, radical or controversial content which attracts large amounts of engagement. This can act to the detriment of evidence-based health information that is often not glamorous or exciting, with potentially lower engagement as a result and therefore lower perceived credibility.

Another important way in which influencers often develop credibility among their audience is by building parasocial relationships. These are one-sided relationships between an individual and a media figure, formed through sharing personal stories, regular interaction and perceived closeness. These relationships can increase trust and loyalty, making audiences more receptive to health advice and product recommendations^4,17.

However, credibility assessments are nuanced and at times contradictory. While one study found official institutions like the CDC or FDA in the US were seen as credible due to their expert status¹⁹, another study found influencers may be perceived as more authentic – and thus credible – precisely because they operate independently of institutional constraints²⁰. This signifies at a tension point in the public trust of health information sources. Further, it indicates an opportunity to leverage the complementary strengths of public health bodies and influencers to create credible, authentic, relatable and evidence-based public health messaging and campaigns to improve health outcomes.

Individual-level implications

On an individual level, influencers can be drivers of healthier diet and exercise habits, supporting people to feel empowered to improve their health through shared experiences and accessible information. Influencers can create communities online, providing social support and potentially even aiding diagnoses of illnesses through sharing their own experiences. However, they can also contribute to body dissatisfaction, inaccurate self-diagnosis, delayed treatment, unhealthy food intake – demonstrably among children – and promote unnecessary supplements or tests under the guise of health promotion, all of which can impact individual health.

As research demonstrates that influencers may also contribute to promoting certain idealised body images online, the commercial element and effective marketing may derive from this relationship. By showcasing a curated lifestyle online and then endorsing a product, audiences may feel compelled to purchase the product to achieve a certain physique or lifestyle. This could have a financial impact at the individual level, whereby people unnecessarily spend money on products with minimal or nonexistent health benefits.

Finally, algorithms can play a significant role with individual-level consequences. Algorithms quickly adapt based on what content someone engages with and promote more similar content. This can make influencer communities siloed based on the messages they share, leading to the impression that the content being shown is mainstream and trustworthy, and thus reliable advice. This in turn could lead people to follow trends or fads that are not supported by evidence, with potential detrimental effects on health.

Wider implications

At a societal level, influencer-driven health content risks normalising misinformation around health-related behaviours and promoting diets, products, or medical tests to a vast number of people. These bear potential short- and long-term consequences that can place a strain on health systems. Influencers can also implicitly impact mental and physical health, for example by sharing idealised body imagery or lifestyles. This is an area that requires further research to uncover the full extent to which this occurs and how to effectively mitigate the associated risks. Importantly, social media health influencers could contribute to a growing tension between the public and healthcare systems, where amidst long NHS waitlists and staff shortages, people may feel the need to seek out health advice online.

Nevertheless, it is important to note that many influencers post valuable, informative and evidence-based content that can tangibly improve people’s health and should not be discounted. Especially though building parasocial relationships with their followers, influencers have power to impact audiences’ intentions of engaging in health-promoting behaviours.  As such, there is immense potential in the collaboration between governments and influencers to drive public health campaigns that are evidence-based, meet public health goals, and do so in an approachable and trustworthy manner.

Recommendations

1. Governments should consider collaborating with influencers who demonstrate expertise, trustworthiness and transparency, especially on targeted or time-sensitive public health campaigns, to increase their reach and effectiveness.
2. Stricter restrictions should be placed on the promotion of health-related products such as supplements and medical tests. Clear disclosures should be mandated when promoting such products to outline potential risks, with stronger enforcement by the Advertising Standards Authority in the UK.
3. Social media platforms should make fact-checking and verification processes more rigorous, making it easier for users to identify content and creators that are reliable and evidence-based.
4. Enhanced media literacy education should be considered in schools to teach children and young people how to find health information online while being able to identify misinformation. While it would be impossible and undesirable to stop people from seeking health-related information online, the skills to utilise and critically engage with social media as a tool for information seeking should be taught from a young age.

Lida Kari, March 2026.

References

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2. Guttmann, A. (2025)Topic: Influencer marketing in the United Kingdom (UK), Statista. Available at: https://www.statista.com/topics/7119/influencer-marketing-in-the-uk/#topicOverview (Accessed: 18 December 2025). 
3. Edelman Trust Institute (2025)2025 Edelman Trust Barometer: Special Report - Trust and Health, Edelman. Available at: https://www.edelman.com/trust/2025/trust-barometer/special-report-health (Accessed: 21 December 2025). 
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