Finding impact, not visibility: where HCP scientific conversations really happen

What the evidence tells us about how HCPs influence each other online

The conversation about how healthcare professionals use social media for clinical education and learning has matured considerably over the past decade. What the research now shows clearly is that different platforms have developed distinct roles in HCP professional life. Understanding those roles, and the purposes each platform serves, is essential for anyone working to identify and engage the voices that genuinely shape clinical practice.

A landscape of platforms, each playing a different role

The healthcare professional social media landscape is not one conversation taking place across multiple venues. It is a set of quite different conversations, each shaped by the platform it lives on. Today, X remains the dominant platform for large-scale public peer-to-peer scientific discourse among healthcare professionals. LinkedIn is for careers and professional networking. Instagram has become a meaningful venue for visual medical education, particularly in image dependent specialties. Peer reviewed research has documented its educational use in radiology and pathology, with separate peer reviewed evidence documenting its widespread adoption in dermatology for both patient and professional education. The platform’s visual format suits case sharing, teaching points and rare disease awareness. A resident led multidisciplinary teaching initiative on Instagram demonstrated significant engagement among medical learners.. YouTube is the dominant home of surgical and procedural video learning. TikTok is overwhelmingly patient-facing. Closed channels such as WhatsApp, Telegram, Sermo and Doximity host valuable clinical case discussion but sit behind privacy walls that, rightly, prevent external observation. And Bluesky, the most recent entrant of consequence, has shown early signs of adoption among parts of the science and medicine community.

These distinctions matter. A healthcare professional sharing the same insight on each of these platforms would reach a different audience, generate a different kind of engagement, and produce a different signal of peer influence. The question for anyone trying to identify Digital Opinion Leaders is therefore not “which HCPs are online” but “where is the conversation that actually matters to me happening, and on whose terms”.

Why this matters for Medical Affairs teams

For Medical Affairs teams, this distinction has practical consequences. If your objective is to identify the clinicians who are shaping scientific discussion within a disease area, understanding where peer-to-peer engagement actually takes place becomes critical.

A physician with thousands of LinkedIn connections may be highly visible professionally, yet have little online influence on clinical debate. Conversely, a specialist with a relatively modest social following may be routinely cited, amplified and trusted by online peers discussing a particular therapy area.

Visibility is not the same as peer impact. In a clinical context, influence is ultimately a reflection of peer trust: whether other healthcare professionals choose to reference, amplify and engage with an individual’s contributions.

Many healthcare professionals post frequently online, but far fewer consistently shape the thinking of their peers. The key signal is not activity alone, but whether other healthcare professionals reference, amplify, discuss and engage with that individual’s contributions.

For teams seeking to identify Digital Opinion Leaders, understanding where these peer influence signals are most visible is therefore more important than simply knowing which healthcare professionals maintain an online presence. To understand where those signals can be observed, it is first necessary to understand the different roles that social platforms play in healthcare professionals’ digital lives.

What the evidence shows about X and HCP scientific conversation 

The research on physician behaviour on X is now substantial and consistent. Hasham et al. (2025), writing in the International Journal of Academic Medicine, describe X as facilitating professional development, global networking, and real time discussions on medical advancements among healthcare professionals. This is not incidental usage, indeed it reflects the platform’s fundamental design as a space for public, rapid, peer to peer exchange.

The nature of that exchange has been studied across multiple specialties. Research published in Crohn’s & Colitis 360 found that HCP to HCP engagement on X was more frequent than engagement between HCPs and any other stakeholder group, and that the primary purpose of that engagement was knowledge sharing, particularly around research, along with dissemination of clinical findings and peer commentary. Physicians and other non physician HCPs were significantly more likely to repost content written by another physician than content from any other source.

This pattern of peer driven amplification is consistent across disciplines. A review of X’s role in interventional cardiology found that among healthcare professionals from 35 countries, X was among the most widely used social media platforms for professional purposes. A study of #FOAMed (Free Open Access Medical Education), published in 2025 in the Western Journal of Emergency Medicine, found that discourse on X remains dynamic and responsive to clinical priorities, shaped by peer interaction, and that content quality rather than volume was the primary driver of visibility. A four year analysis of #EndoTwitter documented over 58,000 posts generating more than 46 million impressions across 148 countries, with healthcare workers the main contributors.

Research in infectious diseases described X as “the only platform that allows one to connect, engage, learn, and educate oneself and others in real time on a global scale”. A qualitative JMIR study found healthcare professionals use X for rapid access to succinct clinical knowledge, networking, and peer reassurance regarding clinical cases, evidence, and policy. Research at the intersection of cardiology and social media education describes cases where clinician led Twitter movements have influenced practice guidelines and shaped clinical standards. The cross cutting theme is consistent, X is repeatedly described in the literature as uniquely suited to real time, global, public scientific exchange among clinicians.

How LinkedIn fits into the HCP digital ecosystem

None of this diminishes LinkedIn’s value for healthcare professionals. It is a powerful tool for career management, institutional networking, and professional visibility. But the evidence suggests that is precisely what it is for, and not much more.

What LinkedIn is not, by design, is a platform for real time public clinical discourse. A cross sectional study of physician social media in JAMA Network Open by Hameed and colleagues found LinkedIn had the highest profile penetration of any platform among the physicians studied, but that across all platforms 89.3% of physicians with a public profile had zero monthly posts. LinkedIn presence functions largely as a static professional record rather than active clinical discourse, with HCPs using the platform primarily for career visibility, institutional networking and recruitment, and for sharing actions related to clinical congresses and symposia, rather than for real time scientific exchange. Studies on LinkedIn use in professional contexts consistently show that it delivers informational benefits for career and professional development. Healthcare Success describes LinkedIn as a natural doctor to doctor communications channel and pathway for referrals and professional networking, with its original purpose being to support career advancement.

Its architecture prioritises sustained professional relationships over real time public discourse. Although LinkedIn has introduced followers alongside the connections model, its algorithm favours network based distribution and walled group discussions over the open hashtag conversations that drive amplification on X. The kind of rapid, peer visible, publicly amplifiable scientific exchange that happens on X simply does not occur there in the same way. There is also a practical dimension that matters for any organisation working with HCP social data. The legal and ethical framework around LinkedIn data means that it cannot be collected or analysed at scale in the way that open platforms permit. This is not a technical limitation; it is a deliberate reflection of LinkedIn’s design as a closed professional network.

The wider platform picture

Beyond X and LinkedIn, the rest of the landscape divides into platforms that serve specific clinical functions and platforms that operate behind closed walls.

Instagram occupies a somewhat different role within the HCP digital ecosystem. While it is increasingly used by healthcare professionals, particularly in visually oriented specialties, much of that activity is focused on public education, patient communication and awareness building rather than peer-to-peer scientific debate.

Nevertheless, Instagram has become a meaningful venue for visual medical education. Peer-reviewed research has documented its educational use in specialties such as histology, where the platform’s visual format suits case sharing, teaching points and disease awareness. A resident-led multidisciplinary teaching initiative on Instagram also demonstrated significant engagement among medical learners.

For this reason, Instagram should not be viewed as a direct equivalent to X. Rather, it provides a complementary perspective, particularly in specialties where visual content plays an important role in education and influence.

YouTube tends to be the dominant video resource for surgical and procedural learning. A peer reviewed survey reported that 90% of surgeons used video sources for surgical preparation, with YouTube the most cited. A consistent caveat across studies is that YouTube content is unvetted and quality is variable, which has prompted calls for clinician led standards in surgical video sharing.

TikTok sits in a different category. It tends to be overwhelmingly a patient facing platform. Research published in JMIR Infodemiology found that HCP created content represents a small minority of clinical TikTok content, although where it exists it tends to be evidence based. The platform’s primary clinical relevance is as a patient education and misinformation (moderation) environment, not a peer to peer professional one.

Reddit warrants a brief mention for completeness, though for different reasons to the other public platforms. It is a discussion platform built around topic specific communities known as subreddits, and it has active medical communities including r/medicine and r/askdocs where verified healthcare professionals engage in clinical and professional discussion. Peer reviewed ethnographic research on r/medicine has documented how the platform’s combination of anonymity and active community moderation creates space for HCPs to discuss sensitive topics, share difficult clinical experiences, and exchange honest opinion in ways that are harder on identity attached platforms. Similar peer reviewed work has examined HCP and patient discussion patterns on Reddit in radiation oncology, ophthalmology and dermatology. However, the same anonymity that enables candid discussion makes Reddit fundamentally unsuited to digital opinion leader identification. Individual HCPs cannot be identified, verified or attributed across the platform, and influence in a subreddit accrues to pseudonymous accounts rather than to named clinicians whose peer impact can be measured and engaged. For pharma audiences, Reddit is best understood as a useful environment for understanding HCP sentiment and patient perspectives in aggregate, but not as a source of identifiable opinion leaders.

Bluesky is the most recent platform of note. There is some early evidence of adoption among parts of the science and medicine community, particularly in hematology and breast oncology, following moves by societies such as the American Society of Hematology in late 2024. Reporting from STAT News and Science has documented these early moves. However, the practical scale remains modest compared with X, and the broader HCP community on Bluesky is still small and concentrated in pockets. It is a platform worth monitoring rather than one currently rivalling X for public clinical discourse.

Closed and semi-closed networks host a great deal of genuine clinical conversation that simply cannot be observed externally. WhatsApp and Telegram have become significant clinical communication channels, particularly in low and middle income countries where systematic reviews have documented their use for surgical consultation and case discussion. Physician-only platforms such as Doximity in the United States and Sermo globally offer verified, credentialed environments for clinical discussion, professional networking and survey participation. These are valuable channels for the HCPs who use them, but by design they are not open to public observation and are exclusively accessed through permission based engagement rather than listening at scale.

A comparative view

What this means for identifying Digital Opinion Leaders

For pharma digital and medical affairs teams seeking to understand who is genuinely shaping clinical conversations in a therapeutic area, the platform distinction is not a nuance.  Peer influence in a clinical context is not about who has the most professional connections or the most polished institutional profile; it is about whose ideas are being actively endorsed, amplified and debated by other verified healthcare professionals in real time.

This distinction becomes even more important when identifying emerging Digital Opinion Leaders. Established KOLs are relatively easy to find through publications, congress activity, professional networks and existing stakeholder databases. Emerging Digital Opinion Leaders, however, are not easily seen through such a lens.

Emerging peer impact develops first within conversations, and becomes visible when healthcare professionals begin referencing, amplifying and engaging with a clinician’s contributions before that individual has necessarily built a traditional reputation through publications, leadership positions or advisory roles.

Identifying these emerging voices requires more than knowing which HCPs have a social media presence; it requires understanding which individuals are increasingly shaping peer-to-peer scientific discussion within a disease area, and where those influence signals can be observed.

Those peer impact signals are most visible in a small number of public digital environments.. They are most strongly observable on X, where the body of peer reviewed evidence is consistent and substantial. They extend to Instagram for specialties where visual content carries clinical weight. And they include Bluesky as an emerging space worth monitoring, particularly in oncology and hematology communities. Taken together, these three platforms cover the public spaces where peer to peer clinical discourse is happening today, and where it is most likely to continue to grow in the future.

The closed channels matter too, but they are reached through different methods, with permission, or direct engagement rather than observation. And the platforms outside this picture (LinkedIn, YouTube, TikTok and Facebook) each serve real and valuable HCP functions, yet those functions are not principally about real time peer influence in scientific discourse.

For organisations seeking to identify and engage genuine Digital Opinion Leaders, the practical implication is straightforward. The question is not whether healthcare professionals use LinkedIn, Instagram, X, YouTube or Bluesky – they do. The question is which platform reveals the signal you are trying to measure. If your objective is professional networking, LinkedIn may be invaluable. If your objective is identifying the clinicians who shape scientific conversation, influence peer behaviour and drive discussion within a therapeutic area, the evidence points overwhelmingly towards the public peer-to-peer channels where that discourse actually takes place.

CREATION.co’s DOL Finder platform identifies and ranks Digital Opinion Leaders using public peer impact signals across X, with Instagram and Bluesky integration extending coverage to the spaces where clinical discourse is growing. By focusing precisely on the platforms where verified HCPs engage in public scientific exchange, DOL Finder measures the peer influence that genuinely moves clinical conversations, while HCP Horizon provides therapy area-wide insights from analysing the combined overall conversation across all three platforms. 

Join our upcoming webinar to see how HCP Horizon and DOL Finder can help teams understand what HCPs think – and who is shaping the conversation.