The role of the Medical Science Liaison (MSL) has moved from relative obscurity to strategic necessity in today’s complex healthcare and biopharma landscape. With the rapid growth of specialty therapeutics, rare disease management, and evidence-based medicine, U.S. healthcare organizations are rethinking how clinical expertise connects with product innovation. The MSL sits at the intersection of clinical science and industry, translating cutting-edge research into real-world patient impact—and vice versa.
But what exactly does an MSL do, and how does one become effective in this unique hybrid role? In a recent episode of the American Journal of Healthcare Strategy podcast, Mohammadreza (Moe) Abouzari, DPM, former Senior Medical Science Liaison at Ascendis Pharma, offers a rare, firsthand perspective that challenges outdated notions of clinical vs. corporate career tracks. His journey from analytical chemist to DPM to board-certified MSL illustrates the multi-dimensional, deeply human side of this profession. Whether you’re an executive, clinician, or advanced student eyeing a future in pharma or medtech, understanding the MSL’s evolving value proposition is essential.
A Medical Science Liaison (MSL) is a clinically trained professional who bridges the gap between pharmaceutical or medical device companies and healthcare practitioners by providing peer-level education, gathering field insights, and ensuring ethical data communication. This role is distinct from sales—it centers on trust, credibility, and knowledge-sharing.
Dr. Abouzari explains, “Medical Affairs came to reality probably about 20 years ago when biotech and pharma companies realized that a sales rep can sell a product, but you need someone at a peer level who can educate or support that product, and also present the data in a way clinicians can trust.”
Unlike sales reps, MSLs are credentialed—often PharmDs, PhDs, MDs, or in Dr. Abouzari’s case, a DPM/MBA—with deep clinical and scientific backgrounds. They don’t just deliver information; they contextualize it for busy clinicians, often becoming the go-to resource for complex, off-label, or comparative effectiveness questions.
Key responsibilities of an MSL include:
Educating healthcare providers on therapeutic areas, product science, and clinical trial data
Facilitating peer-to-peer scientific exchange
Collecting actionable field insights and unmet needs to bring back to R&D or marketing
Supporting clinical trials and post-market research initiatives
Acting as the “voice of the customer” to internal teams, especially in product development
This bidirectional flow—education and insight gathering—explains the term “liaison.” As Dr. Abouzari puts it, “The notion of the word liaison is truly a bidirectional thing: you teach, but at the same time you get insight and bring it back to the company from the thought leaders and clinicians you talk to.”
Dr. Abouzari’s journey to becoming an MSL was anything but linear, illustrating that diverse backgrounds can yield exceptional industry impact. He started with a bachelor’s in chemistry and biochemistry, working as an analytical chemist and even training as a certified mechanic—skills that honed both his scientific acumen and manual dexterity.
“My dad was a mechanical engineer, so a mix of all those things allowed me to be very good with my hands. As part of being an analytical chemist, you need to understand how the science works, but you also have to work with instrumentation, which means understanding mechanical and electrical diagnostics,” Abouzari shares.
A deeply personal motivator led him into podiatry: “My dad had a lot of foot problems, and after visiting five to ten different doctors, a DPM was the one who finally diagnosed him and gave him the remedies he needed. That played a very important role in my mindset.”
Abouzari’s pivot to industry came serendipitously during a wound care fellowship at UC San Diego, where a mentor introduced him to the world of Medical Affairs—a career path not discussed in most clinical training.
“When you go to professional schools, they teach you that you’re going to finish, go through residency, do your boards, and start practicing. Nobody teaches you about the alternatives—what you can do with your degree,” he recalls.
What stands out: The MSL field welcomes those who blend clinical rigor with analytical and interpersonal skills. Diverse professional backgrounds—whether chemistry, nursing, or podiatry—are often assets, not limitations.
While the most common path to MSL is via advanced clinical or scientific degrees (PharmD, PhD, MD, DPM), the real barrier to entry is demonstrating peer-level expertise, communication skills, and business acumen.
“Not having an MD, PharmD, or PhD does make it a little bit more difficult, because hiring managers often don’t know what your background brings. My degree as a DPM is actually a subspecialty of orthopedic surgery. You can diagnose the same as an MD—you go through the same training, sometimes even more,” says Abouzari.
The MSL Society and other organizations now offer board certification for MSLs, aiming to standardize and raise the bar for this profession. Dr. Abouzari was among the first to participate:
“Back in 2018, the Medical Science Liaison Society put together a comprehensive look at Medical Affairs and the requirements of MSLs in the field. About 120 individuals took the exam, and I was fortunate enough to pass as one of about 30 from the medical device side.”
To become an MSL, you typically need:
An advanced degree in life sciences or medicine (PharmD, PhD, MD, DPM, etc.)
Field experience—clinical, academic, or industry research is highly valued
Strong presentation, networking, and communication skills
Commitment to ongoing education (e.g., CME credits, attending conferences)
Increasingly, board certification or formal training through organizations like the MSL Society
The day-to-day reality of an MSL varies widely based on company size, product type (pharma vs. medical device), and stage of commercialization. However, all MSLs are field-based, engaging directly with clinicians, researchers, and healthcare decision-makers.
Dr. Abouzari breaks it down: “If you’re working for a large company with many MSLs and smaller territories, you probably have a pretty good work-life balance. In a startup environment, it’s different—the travel can get horrendous, field work can be intense, but you also get to do more than the traditional MSL role.”
Key activities include:
Educating healthcare professionals at hospitals, conferences, and symposia
Organizing and presenting at journal clubs, advisory boards, or scientific meetings
Supporting field teams in answering complex, often off-label, medical questions (sales teams cannot legally answer these)
Building relationships with Key Opinion Leaders (KOLs)
Gathering feedback on real-world product performance and unmet needs
Participating in or supporting clinical research initiatives
Career progression:
Many MSLs advance to roles such as Medical Affairs Manager, Director, or VP of Medical Affairs.
Others transition into related fields: clinical development, regulatory, health economics, or commercial strategy.
Abouzari notes, “A lot of times, your responsibility narrows down a little bit because you’re focusing on certain products. When you deal in patient care, you’re dealing with a patient that comes with multiple diseases. As an MSL, you’re able to dive deep into a therapeutic area.”
Unlike clinical practice, where patient care is the focus, or academia, where research and teaching dominate, MSLs operate at the crossroads—translating science into practical, market-relevant solutions.
“As a field expert, you attend conferences where you have two roles: learning about new products and, as an MSL, sometimes presenting on data your company has produced. You might help create posters, present lectures, or support competitive market analysis,” Abouzari explains.
Key differences include:
Scope of Influence: MSLs may impact thousands of patients through provider education and product support, while clinicians focus on direct care.
Nature of Work: MSLs sell their knowledge and their company’s data, not a product per se—“What I sell is my knowledge and what I sell is the data that my company has created. Without that, sales folks don’t have anything to present except maybe financial data,” says Abouzari.
Stakeholder Engagement: MSLs engage with executives (CFOs, CEOs, CMOs), providing health economic analyses and strategic support.
For those driven by intellectual challenge and real-world problem-solving, the MSL path can be more stimulating than direct patient care or pure research.
Work-life balance for MSLs is highly variable, but the profession often offers more autonomy and less “burnout risk” than hospital-based clinical roles. Compensation is competitive, with median U.S. MSL salaries ranging from $140,000 to $180,000, according to 2024 industry reports.
Dr. Abouzari is frank: “If you’re working in a startup, there are times when travel gets horrendous and your work-life balance isn’t there. But as the product becomes more established or your team grows, things tend to calm down.”
Key points:
Compensation can exceed that of clinical roles, especially when factoring in bonuses and benefits.
MSLs focus on specific products or disease states, reducing the “cognitive overload” of managing multiple comorbidities.
“One of the benefits is your responsibility narrows down a little bit because you’re focusing on certain products,” says Abouzari. “In patient care, you’re dealing with a patient that comes with multiple diseases or conditions.”
There are trade-offs: Some miss the “hands-on” nature of clinical work, but others find the impact of field education and strategic influence more fulfilling.
To succeed as an MSL, you need a mix of clinical acumen, scientific curiosity, and genuine interpersonal skills. Extroversion, resilience, and comfort with ambiguity are essential.
“In order to be a good MSL, you need to be extrovert. If you’re an introvert, it’s going to be very difficult. You have to feel comfortable in front of a room full of people who will have questions for you regarding your product or competition,” says Abouzari.
Core attributes for MSL success:
Peer-level credibility: Clinical or scientific expertise, board certification helps
Communication: Ability to explain complex science simply and persuasively
Curiosity: Lifelong learning—“I always love to learn and I always love to read, even stuff that I have no business about reading,” Abouzari notes
Adaptability: Navigating regulatory, market, and organizational change
Networking: Building deep relationships with clinicians, KOLs, and internal stakeholders
Breaking into MSL roles isn’t easy, but targeted networking, professional development, and a strategic approach can make the difference. Dr. Abouzari emphasizes persistence and intentional relationship-building.
“Try to network within your field with as many MSLs, Medical Affairs managers, and VPs as you can. Reach out and say, ‘Hey, I want to enter this field. Can I ask a few questions?’ It’s not a field that happens overnight—you have to do your homework,” he says.
Practical steps:
Build your network: Attend industry conferences (e.g., Infectious Disease Society of America, American Society of Microbiologists), connect with current MSLs, and participate in seminars by groups like the MSL Society and MAPS.
Learn continuously: Read books such as Breaking Into Your First MSL Role by Dr. Samuel Jacob Dwi, consume industry publications, and stay updated on clinical and regulatory trends.
Consider board certification: Adds credibility and shows commitment.
Be flexible: Sometimes you’ll need to start in adjacent roles—research, clinical education, or scientific consulting—before landing your first MSL job.
Engage locally: “Don’t be afraid to talk to vendors—they may be your gateway into a company. Grab coffee with Medical Directors. There are a lot of great people out there willing to talk to you and give you a few minutes of their time,”* says Abouzari.
Pro tip: Dr. Abouzari’s own entry into Thermo Fisher as an MSL came via a relationship with a practicing MSL: “She was instrumental in getting me into Thermo Fisher. I did most of my work prior to that as a consultant, building analytical laboratories and working for several startups.”
In 2025, the MSL is a strategic differentiator—crucial for product launches, real-world evidence generation, and clinician adoption. The U.S. market, in particular, demands peer-to-peer credibility in an environment of increasing regulatory scrutiny and rapid innovation.
MSLs help companies:
Accelerate product uptake by educating influential clinicians and thought leaders
Navigate complex payer and provider landscapes through field-based insights
Shape clinical trial design and real-world evidence collection
Anticipate and mitigate market access challenges by understanding what matters to healthcare systems, not just individual prescribers
“One of my roles allowed me to do health economic presentations to CFOs, CEOs, and CMOs, and that brings a whole new level of involvement,” Abouzari notes.
The most forward-thinking organizations integrate their MSLs deeply into cross-functional teams, leveraging them as “sentinels” for market change.
The Medical Science Liaison is more than a technical expert—they are an architect of connection in the fractured world of U.S. healthcare and biopharma. Dr. Moe Abouzari’s journey exemplifies the adaptability, curiosity, and human touch required to succeed. If you’re considering a leap into Medical Affairs, take his advice to heart: network relentlessly, invest in your learning, and approach the role with the humility of a lifelong student and the confidence of a peer. In a system where science and strategy are always evolving, the best MSLs are those who bridge gaps, ask better questions, and never stop learning.
