By Samuel Dyer, MD, PhD; CEO-Medical Science Liaison Society
The role of the Medical Science Liaison (MSL) has evolved significantly over the past two decades, transitioning from a niche scientific support function into a strategic role within Medical Affairs. Today, MSLs are essential in facilitating high-quality scientific exchange with key opinion leaders (KOLs) and other health care professionals (HCPs), supporting clinical development, and ultimately contributing to improved patient outcomes. MSLs are now employed across pharmaceutical, biotechnology, medical device, medical diagnostic, and contract MSL organizations, reflecting the continued expansion and importance of the role across the healthcare industry.
At its core, the primary purpose of an MSL is to help healthcare professionals make more informed clinical decisions through unbiased, evidence-based scientific exchange. Unlike pharmaceutical sales representatives and other commercial roles, MSLs operate in a non-promotional capacity, serving as unbiased medical resources to key opinion leaders (KOLs), HCPs, and the broader medical community.
As the pharmaceutical industry continues to grow in complexity, the demand for highly skilled MSLs has increased significantly over the last several years. The role is now one of the most competitive and sought-after career paths, particularly among pharmacists and other clinically trained professionals. Despite this demand, the role remains widely misunderstood, even within the industry.
Having coached, trained, and helped launch hundreds of MSL careers globally, one question continues to surface: What truly differentiates a great MSL from a good one?
Scientific Credibility and Depth of Knowledge
A foundational requirement for any successful MSL is deep scientific expertise. MSLs must possess a comprehensive understanding of their therapeutic area (e.g., Neurology, Cardiology, or Oncology), including disease-state knowledge (e.g., Parkinson’s disease, hypertension, or non-small cell lung cancer), along with clinical data and evolving treatment landscapes.
Within the MSL role, depth of knowledge is critical for enabling meaningful, high-level scientific exchange. MSLs must be able to communicate complex scientific information clearly, confidently, and in a way that is directly relevant to the clinical practice of the KOLs and HCPs they are supporting.
However, great MSLs go beyond simply knowing the data. They understand how to translate that data into meaningful, clinically relevant discussions tailored to each KOL or HCP. They anticipate questions, contextualize findings, and provide insights that add real value to clinical decision-making.
In a global survey involving 245 KOLs conducted by the Medical Science Liaison Society, “depth of knowledge” was selected as the most important key factor that makes an MSL stand out from others. This reinforces that scientific credibility remains a critical component of excellence.
In a global survey involving 245 KOLs conducted by the Medical Science Liaison Society, in response to the question, “What makes a really good MSL stand out from other MSLs?”, KOLs selected “depth of knowledge” as the most important key factor. This reinforces that scientific credibility remains a critical component of excellence.
Honest, Unbiased Scientific Exchange
Equally important, and often more differentiating, is the ability to communicate in a manner that is objective, transparent, and free from commercial bias. In the same survey conducted by the Medical Science Liaison Society, KOLs revealed “honest and unbiased” as the second most important key factor in response to the question, “What makes a really good MSL stand out from other MSLs?”
This further reinforces that trust, integrity, and objectivity are fundamental to establishing credibility and building strong, long-term value-added relationships with KOLs. Ethical communication, integrity, and transparency are fundamental standards for MSLs in maintaining credibility with healthcare professionals.
Great MSLs embrace this responsibility. They do not avoid difficult questions or unfavorable data. Instead, they address them directly, reinforcing their role as trusted scientific partners rather than product advocates.
Exceptional Communication and Listening Skills
Scientific knowledge alone is not enough. The ability to communicate effectively, and more importantly, to listen, is what transforms information into impact.
Strong communication skills are a defining capability of high-performing MSLs, particularly in conveying complex medical information clearly while building meaningful, trust-based relationships with KOLs and other HCPs.
For MSLs, this goes far beyond delivering presentations. It involves:
- Asking thoughtful, relevant questions
- Actively listening to HCP perspectives
- Adapting communication style based on the audience
- Engaging in two-way scientific dialogue
The most effective MSLs recognize that the value of an interaction is not measured by how much they say, but by how well they understand the HCP’s needs, challenges, and insights.
Ability to Generate and Communicate Actionable Insights
One of the most critical and strategic responsibilities of an MSL is generating and communicating actionable insights from the field. This capability is a key driver of the value that MSLs bring to Medical Affairs organizations.
Every engagement with a KOL or an HCP presents an opportunity to identify insights related to clinical practice, unmet needs, treatment decision drivers, and perceptions of emerging data. However, the true impact lies not simply in gathering information, but in identifying insights that are meaningful, relevant, and aligned with broader medical strategy.
High-performing MSLs are able to distinguish between general observations and true actionable insights. They connect field-based learning to strategic priorities and communicate those insights to inform internal decision-making.
When effectively leveraged, these insights can influence medical strategy, shape clinical development plans, guide evidence generation, and refine engagement approaches. Ultimately, this contributes to improving patient outcomes by ensuring that organizational decisions are grounded in real-world clinical perspectives.
Emotional Intelligence and Relationship Building
While scientific expertise and communication skills are essential, emotional intelligence is often the defining factor that separates good MSLs from truly exceptional ones.
MSLs frequently engage with highly experienced, time-constrained, and sometimes skeptical healthcare professionals. Building trust in these environments requires authenticity, empathy, adaptability, and strong professional presence.
Relationship-building in this context is not transactional. It is developed over time through consistent, high-value interactions that prioritize the HCP’s needs.
Strategic Thinking and Business Acumen
MSLs are no longer limited to reactive scientific support or discussions with KOLs. The role has evolved into a highly strategic function that requires a deep understanding of the broader healthcare and organizational landscape.
Great MSLs think beyond individual interactions. They develop and execute strategic KOL engagement plans, align their activities with clinical and organizational priorities, understand the competitive landscape, and contribute to cross-functional initiatives.
Adaptability in a Rapidly Evolving Environment
The pharmaceutical industry and healthcare landscape are constantly evolving, driven by new data, regulatory changes, and technological advancements.
Successful MSLs must be adaptable, continuously learning and refining their approach. The ability to adjust to new information, therapeutic developments, and stakeholder expectations is critical in maintaining relevance and effectiveness.
The Growing Importance of the MSL Role
The continued growth of the MSL role reflects a broader shift toward more scientific, data-driven, and patient-centered engagement across the healthcare industry.
With increasing complexity in clinical data and higher expectations from healthcare professionals, the need for credible, non-promotional scientific exchange has never been greater. MSLs are uniquely positioned to meet this need and are increasingly recognized for their impact on clinical practice, research collaboration, and patient outcomes.
Conclusion
A great Medical Science Liaison is not defined by a single skill, but by a combination of scientific expertise, integrity, communication, and strategic thinking.
The data is clear. KOLs value honesty and depth of knowledge above all else. However, it is the integration of these qualities with emotional intelligence, insight generation, and adaptability that truly sets exceptional MSLs apart.
As the role continues to evolve, those who embrace both the science and the human element of the position will not only stand out but will play a critical role in shaping the future of healthcare.
Author Bio
Dr. Samuel Dyer is the CEO of the Medical Science Liaison Society and has over 26 years of international MSL experience. During his career, he has managed MSL teams and operations in over sixty countries across the United States, Canada, Europe, Africa, the Middle East, Australia, and New Zealand. He has facilitated the successful launch of pharmaceutical and medical device products for both Fortune 500 pharmaceutical companies and small biotechnology companies.
