What is a Medical Science Liaison (MSL)? The 2025 Career Guide

You’ve probably heard the title before: Medical Science Liaison.

Sometimes it’s whispered like it’s a secret club in pharma. Other times, it’s confused with sales. And if you’ve tried explaining the role to friends or family, you may have gotten the polite nod and the look that says, “I have no idea what you do.”

If that’s you, you’re not alone.

The truth is, the MSL role is one of the most unique and misunderstood careers in the life sciences industry. It’s a job that blends deep science with strategic influence, and when done right, it changes how medicine is practiced.

Whether you’re curious about breaking in, new to the role, or leading a team, this guide will give you the clearest, most current picture of what an MSL is in 2025 and how their impact goes far beyond delivering data. In this 2025 career guide to what is a Medical Science Liaison, we’ll break down the role, how it fits within the bigger picture of Medical Affairs, and why MSLs are one of the most in-demand, high-impact careers in pharma and biotech today.

What Is a Medical Science Liaison (MSL)?

A Medical Science Liaison (MSL) is a field-based medical affairs professional who connects pharmaceutical, biotech, or medical device companies with the healthcare community. Not to sell products, but to share and exchange medical and scientific information that can influence patient care.

MSLs are trusted partners to the top experts in their field, known as Key Opinion Leaders (KOLs), and they play a strategic role in shaping how data, clinical trials, and real-world evidence are understood and applied.

Today, the role reaches far beyond academic KOLs. MSLs now engage across the full healthcare continuum, from leading researchers and community specialists to advanced practice providers (APPs) such as nurse practitioners (NPs) and physician assistants (PAs). These clinicians often guide treatment decisions and shape how therapies are used in real-world practice.

Because each stakeholder group has its own priorities, challenges, and preferred ways of engaging, building access requires tailored strategies. MSLs adapt their approach for each, whether preparing a deep scientific discussion for a researcher or a practical, patient-focused exchange for an APP managing a high patient load. We cover this in depth in our KOL and HCP Access training program for teams. The same principles apply whether you’re earning the trust of a top-tier academic or a high-volume community provider.

💡 Related reading: If you want to understand why companies invest so heavily in these roles, check out our post The $200,000 Question: Why Do MSLs Get Paid So Much?

The MSL Elevator Pitch

An elevator pitch isn’t just for interviews; it’s how you explain your role to anyone, anywhere, in a way that clicks. The words you choose will shift depending on who’s asking, but the essence stays the same: you’re a scientific expert who builds trusted relationships to improve patient care. Every MSL should be able to explain their role in 15 seconds and tailor it to their audience. Here are four field-tested versions:

MSL Elevator Pitch For Your Family and Friends

“You know those medicine commercials you see on TV? I’m the person who talks to doctors and other healthcare professionals behind the scenes, helping them understand which treatments are right for which patients. I answer questions about complex medications and share the latest scientific data so patients can benefit from the best possible care.”

MSL Elevator Pitch For Internal Colleagues (Medical Affairs, Market Access, Sales)

“I’m a field-based scientific expert who meets with healthcare decision-makers to exchange insights and support our medical strategy. I bring back real-world perspectives that help us refine our data communication, anticipate market needs, and ensure our work delivers measurable value, all while staying compliant.”

MSL Elevator Pitch For KOLs and HCPs

“I’m part of the medical team for [company/product/therapeutic area]. My role is to provide you with up-to-date, balanced scientific information and learn from your clinical experience. That way, we can make sure new evidence is applied in ways that truly support your practice and benefit your patients.”

MSL Elevator Pitch For Networking or Industry Events

“I’m a Medical Science Liaison, a field-based medical professional who connects our company’s science with the healthcare community. I focus on building relationships with the experts shaping clinical practice so we can share evidence, exchange insights, and work toward better patient outcomes.”

Build Your Own MSL Elevator Pitch

A strong MSL elevator pitch should answer three things quickly:

• Who you are (your role and credibility)
• What you do (in plain language)
• Why it matters to them (the value you bring to their world)

Think: Role → Action → Impact

The 3-Step Formula
“I’m a [role/credibility statement] who [what you do] so that [value to them].”

Pro tip: Practice these until they feel natural. You’ll use them more than you think.

What Does a Medical Science Liaison Do?

At its core, the MSL role is about connecting the science to the people who use it and bringing back what those people know to shape company strategy.

MSLs are scientific relationship-builders. They meet with healthcare decision-makers to share meaningful, unbiased medical information and gather real-world insights — all in service of improving patient care.

Think of the MSL role as part scientist, part strategist, and three parts connector. Typical responsibilities include:

• Engaging KOLs and HCPs — Building trust through scientific exchange, not promotion.
• Presenting clinical and real-world data — Tailored to the audience’s expertise and interests (storytelling and not data dumping is key here!).
• Gathering field insights — Capturing and communicating what’s happening in clinical practice back to the company.
• Supporting clinical trials — From site identification to investigator engagement.
• Collaborating cross-functionally — Working with medical affairs, market access, and yes, sales, in a compliant way, to align on strategy.

These aren’t one-off tasks. They’re ongoing, relationship-based activities that can have a long-term impact on how therapies are adopted and used.

💡 Related reading: If you want to see how MSLs turn strategy into action, read Why a KOL List Isn’t a Territory Plan and how the top performers run their territories like CEOs.

Where Do MSLs Work?

If you picture an MSL in a white coat sitting in a lab all day, think again.

MSLs are field-based medical professionals, meaning they spend most of their time out in the real world meeting with healthcare providers where they work, rather than in a corporate office.

That could mean:

• Academic medical centers
• Community hospitals and clinics
• Private practices
• Integrated health systems
• Conference centers and medical congresses

The “field” is wherever their stakeholders are. For some MSLs, that’s a single city or region. For others, it’s a multi-state territory or even international travel. Your therapeutic area shapes your day-to-day, from the size of your territory to the type of KOLs you engage.

Office? What Office?

While MSLs are part of a corporate team, most don’t have a traditional office routine. Their “office” might be a sweet home office setup, multiple monitors, coffee within reach, maybe even a sleeping dog in the background, but their schedule is built around:

• Face-to-face meetings with KOLs and other HCPs
• Virtual scientific exchanges
• Travel to medical conferences
• Collaborating with internal teams remotely

It also means travel is part of the job. Some territories require just a few overnights a month, while others may have you on the road 50–75% of the time (especially for large territories).

Field work is rewarding, but it also comes with unique lifestyle considerations — from travel routines to balancing family life. If you’re curious about what that really looks like, check out these posts from our MSL Mastery community.

💡 Related Reading

• 8 Work Travel Tips for Medical Science Liaisons — Whether you’re clocking a few overnights a month or practically living in airports, these pro tips from experienced MSLs will help you travel smarter, stay organized, and show up ready for every meeting.
• Is the MSL Role Compatible with Being a Parent? — Hear from MSLs and parents on how they balance travel, field time, and family life and the strategies that make it possible.

How Is the MSL Role Different from Sales?

One of the most common misconceptions about the MSL role is that it’s just another form of sales. It’s not and that’s an important distinction for both compliance and how you approach the job.

Sales teams are responsible for promoting approved products and driving revenue. Their success is measured in prescriptions written or units sold.

Medical Science Liaisons, on the other hand, operate within Medical Affairs and are non-promotional. The role is to exchange scientific and clinical information, gather insights from the field, and ensure that healthcare providers have the latest, most relevant data to inform patient care.

That doesn’t mean MSLs work in isolation. In fact, the best MSLs partner closely with sales teams compliantly, aligning on strategic priorities, understanding market needs, and ensuring consistent, evidence-based messaging. Done right, this collaboration benefits patients, strengthens relationships, and helps the organization move faster and smarter.

Think of it this way:

• Sales opens doors and drives adoption.
• MSLs deepen understanding and help make the science stick.

When both roles respect each other’s boundaries and strengths, everyone wins, especially the patients we ultimately serve.

💡 Related reading: If you want to go deeper on building trust and opening doors, read What Sales Reps Understand That MSLs Often Miss and see how top MSLs adapt proven strategies from the best sales reps.

4 Key Skills Every Medical Science Liaison Needs

Scientific expertise? That’s table stakes. It gets you in the door, but it’s no longer the thing that makes you stand out. The MSLs who rise above in 2025 master a different set of skills: ones that shape how insights are gathered, how relationships are built, and how impact is measured.

1. Communication Skills (That Drive Insights and Careers)

The science matters. But so does how you deliver it.

Externally, it’s about making complex information clear, relevant, and actionable for your audience. Internally, it’s the same, but also about showing up in meetings with leadership, even the short, impromptu ones, and communicating in a way that builds credibility fast.

For MSLs, the real magic happens in small, high-stakes conversations, the one-on-one follow-up with a KOL, the debrief with a brand lead, or the 10 minutes you get with senior leadership on a cross-functional call.

There’s also written communication. Take insights, for instance. A lot of valuable observations never become business insights because HQ doesn’t fully understand their significance. The best MSLs know how to package what they’ve learned so its value is obvious and aligned to strategy.

Communication done well:

• Pivots in real time to the conversation flow
• Asks sharp follow-up questions to get the “why” behind what’s said
• Tells stories that make science memorable
• Connects field observations to business priorities
• Delivers updates that make leadership want you in the next meeting

And here’s the career impact: the ability to communicate strategically is one of the fastest ways to get noticed and promoted.

💡 Related reading: Don’t Let Data Go to Waste - How to Tell a Story With Scientific Data
Prefer to listen or watch? Enjoy all MSL Mastery presentation articles. Then listen to an aggregate via podcast or watch a video.

2. Digital Fluency (Beyond the AI Buzz)

You might think “digital fluency” is just another way of saying “learn AI.” Yes, AI is part of it but digital-first thinking goes much deeper and far beyond mastering a single tool. A digitally fluent MSL changes how they think, plan, and engage. They:

• Use data to decide where to spend time and energy
• Spot KOL and HCP trends before the dashboard does
• Flex between in-person, virtual, and async engagement to match stakeholder preference
• Experiment with new tools that make each interaction more relevant and efficient, not just to “check a box”

They use tools to enhance relationships, not replace them.

💡 Related reading: The Digital-First MSL — how to think, plan, and engage like a modern field leader.

3. Cross-Functional Collaboration

One of the top things Medical Affairs leaders call us to train on. Because MSLs can’t work in a silo and “alignment” doesn’t happen by accident.

The most successful MSLs don’t just “work well with others”; they make other people’s jobs easier. They know what matters to their colleagues in Commercial, Market Access, or Clinical Development because they’ve taken the time to learn their metrics and priorities. And then, they use that knowledge to connect the dots, share intel in useful ways, find the win-wins that build trust, build stronger relationships, and get things done.

It’s not just about playing nice. It’s about knowing what your colleagues care about and how you can help them hit those goals while advancing medical priorities.

4. Time & Energy Management

The MSL role is incredibly flexible. It’s also relentlessly demanding.

You set your own schedule, but between travel, scientific updates, internal calls, stakeholder follow-ups, and conferences, the week can disappear faster than a coffee at 6 a.m. in an airport lounge.

High performers treat their time like their most valuable asset:

• Plan their weeks around high-impact priorities, not just meetings
• Use tools to cut busywork and protect focus time
• Leave breathing room for unexpected opportunities (and travel delays)
• Build in recovery so they can actually sustain performance year-round

It’s not about being “always on.” It’s about being intentionally on.

💡 Related reading: Time Audit Workbook: see where your time actually goes, then get it back.

A Day in the Life of a Medical Science Liaison

No two MSL days are the same, and that’s the point. You’re managing your territory like it’s your own business, balancing scientific expertise, strategic priorities, and relationship building.

The flexibility is incredible. The demands are huge. Here’s what a “typical” day might look like.

• 6:00 a.m. – Airport coffee in hand.
  You’re heading to a regional conference to meet three KOLs, catch a late-breaking session, and scan the posters for anything relevant to your TA.
• 9:30 a.m. – First KOL meeting.
  They’re curious about new safety data in your pipeline. You tailor the discussion to their interests, take note of their reaction, and smoothly schedule the next follow-up meeting.
• 11:00 a.m. – Conference hall huddle.
  You run into a Market Access colleague and share intel from your KOL meeting. It sparks a cross-functional idea that could address a regional access gap.
• 1:00 p.m. – Poster session scanning.
  You take quick photos of key findings, flag a competitor trial update, and send a voice note to your medical lead so it’s on their radar before the end of the day.
• 3:00 p.m. – Second KOL meeting.
  This one is virtual. You switch gears quickly, using digital tools to share visuals and keep engagement high despite the screen.
• 5:00 p.m. – Insights reporting.
  Back at the hotel, you type up the day’s key takeaways, link them to business priorities, and submit them in the CRM so HQ can act on them.
• 7:30 p.m. – Quick team call.
  You debrief the day with your manager, align on next steps, and add a follow-up to tomorrow’s plan.
  
  

Why no two days look alike?

• Conferences, investigator meetings, and field visits can shift your week overnight
• Internal projects, ad boards, and brand strategy updates pop up regularly
• KOL needs to change fast, and so does your plan

And if you have a family, the unpredictability isn’t just a work thing, it’s a home thing, too. You might be back from a late flight just in time for school drop-off, or taking a virtual call from the carpool lane. Balancing travel, meetings, and family life is one of the biggest challenges MSL parents talk about and it’s 100% possible with the right systems, boundaries, and support.

💡 Related reading: Is the MSL Role Compatible with Being a Parent? — real stories and practical tips from MSLs who are making both work.

Career Paths for MSLs: The Truth and the Opportunities

One of the worst-kept secrets about the MSL role? The “career ladder” is more like a short step stool.

Most people only see this:
MSL → Sr. MSL → MSL Director.

And that’s where the bottleneck hits. MSL director roles are few and far between, often filled by people who’ve been in the field for years. For many talented MSLs, it can feel like there’s nowhere to go.

But here’s the real story: the MSL role doesn’t have a single linear path. It’s a launchpad. What you build on top of it depends on your strengths and how you want to shape your career.

Staying in Medical Affairs

For those who want to remain in the function, there are options beyond MSL lead. Here are some paths we have seen MSLs take.

• Medical Director roles, where you set strategy and become a therapeutic area expert.
• Training and field enablement, creating training and onboarding for MSLs and scaling best practices across teams.
• Clinical Operations and Development are playing a more direct role in trial execution and support.
• Scientific Communications, shaping publications, congress strategies, and data decks.
• Digital and Omnichannel roles, more common in large companies, where you lead new ways of engaging stakeholders.
  
  

Beyond Medical Affairs

Not every next step keeps you in Medical Affairs. Some MSLs cross into Commercial, sales, marketing, or market access, where their ability to translate science into business value is prized. Others move into consulting or agencies, leveraging their experience across multiple clients. Some, like Sarah, move into training or recruiting, while others embrace entrepreneurship and build their own consulting practices.

And don’t forget the ecosystem that supports pharma and Medical Affairs itself. Vendors, tech platforms, and service companies are hungry for people who’ve lived the MSL role and understand the challenges from the inside. Joining one of these organizations lets you shape solutions for the whole industry, not just one company.

Changing the Setting

Career growth isn’t always about changing functions; sometimes it’s about changing environments. Moving from a large pharma to a small biotech can accelerate learning, because you wear more hats and see the impact of your work faster.

How to Build a Career You Actually Want

The point is: you are not stuck on a ladder with only one rung above you. You’re standing on a launchpad. Where you go next depends less on your company’s org chart and more on the vision you create for yourself.

One of the smartest ways to start? Lead from where you are. Take on “bubble projects” — those small but strategic side efforts that sit just outside your core MSL responsibilities. Maybe it’s helping the med comms team prep for a congress, shadowing clinical ops on a trial, or partnering with digital on an omnichannel pilot.

These projects do two things:

• Show leadership you’re ready to contribute beyond the field
• Help you test-drive future career moves before you leap

They also expand your internal network, which is often how the best opportunities find you.

The MSLs who build fulfilling careers are the ones who:

• Learn their strengths
• Double down on what energizes them
• Carve a path that matches who they are — not just what their job title says

The role is flexible enough to take you in dozens of directions. The real question is: which one feels like yours?

That’s where community helps. In MSL Mastery communities like RISE and LEAP, we see Medical Affairs professionals share career moves, swap stories, and surface opportunities that no single company roadmap could ever predict. When you’re plugged into others who’ve walked the path — and some who’ve paved new ones — the possibilities get a whole lot bigger.

💡 Related reading: Never Leave Your Career Growth in Someone Else’s Hands: why waiting for your boss or company to chart your future is the fastest way to stall your career.

What Is an MSL Salary? (The Question You’re Really Asking)

Let’s cut to it: one reason the MSL role is so competitive is the compensation. Compared to many clinical or academic paths, it’s a big jump.

For PhDs and postdocs, the first paycheck feels like going from instant ramen to “I can actually order sushi on a Tuesday.” For pharmacists, NPs, and physicians, the pay may feel more like a lateral move, but with a very different lifestyle and long‑term upside.

So what are the numbers?

• Entry-level MSLs: $140K–$180K base
• Most roles: $150K–$190K base, often tipping over $200K with bonus/equity
• Senior/Executive MSLs: $190K–$220K+

And here’s the latest market data from pharmapaywatch.com: an analysis of 910 job postings showed the median midpoint at $186K. Companies like Genentech, Gilead, and AstraZeneca topped the charts, often listing roles in the $210K–$225K range. Salary transparency is becoming the norm (finally), which means candidates have more insight than ever into their value.

But here’s the key: don’t obsess over base alone. Total package matters: bonuses, stock, car, benefits, and yes, the travel grind that comes with the territory.

If you’ve ever wondered, “Why on earth are MSLs paid so much?” we break it down here. That’s where we dig into the real reasons behind the six-figure starting point and why companies keep competing for top talent.

The bottom line: the MSL salary is a major draw. The real decision is simpler: do you want the lifestyle and travel that come with it?

Now let’s get to the good part: how do you actually break in? 👇 Keep reading.

💡 Related reading: The $200,000 Question: Why Do MSLs Get Paid So Much?

How to Break into the MSL Role (Without Spinning Your Wheels)

Helping people break into the MSL role is our jam. In 2024 alone, we helped more than 60 people land their first MSL jobs through the Aspire MSL Program.

After working with so many candidates, we’ve seen the same patterns over and over again. Some get stuck for years, while others land interviews and offers within months.

Here are the top three mistakes we see aspiring MSLs make and where to focus instead if you want to break in. This is the 20% that will get you 80% of the results.

Mistake 1: Focusing too much on credentials

Yes, historically, most MSL roles require a terminal degree: PharmD, MD, or PhD. But this is changing. Increasingly, we’re also seeing NPs and PAs break into the role. They bring a unique skillset and perspective to MSLing. We have plenty of advanced practice providers (APPs) in our Aspire MSL Program who’ve done it successfully.

So the degree matters. But it’s just the entry ticket. Credentials are table stakes. Hiring managers don’t stop at “Do you have the right letters after your name?” They ask: “Can you translate complex science into a clear, credible conversation that builds trust?”

That’s why communication skills are the real differentiator. And about “experience”? Here’s the reminder: 100% of MSLs started with zero MSL experience. What gets you hired is how you frame your past work, clinical care, research, teaching, and publications into MSL-ready stories that resonate with hiring managers.

💡 Related resources:

• Webinar Replay: How to Translate Your Transferable Skills Into an MSL Role
• Why Highlighting Transferable Skills Is So Hard
• Personal Branding for MSLs in 2025
  
  

Mistake 2: Playing the application lottery

The “spray and pray” method feels productive: blasting your resume to every opening you see. But here’s what really happens:

• You apply to jobs you’ll never get (wrong TA, wrong geography, wrong fit).
• You rack up rejections.
• Confidence tanks.

It’s not just discouraging; it wastes valuable time. That’s why we teach Aspire members to build a job search strategy instead: targeting roles you’re actually competitive for, tailoring your resume to speak MSL language, and using your time where it counts.

👉 Stop applying everywhere. Start applying smart.

💡 Free webinar: How To Become an MSL Without Experience

Mistake 3: Treating networking as optional

Here’s the truth: MSLs are professional networkers. That’s the job.

If you don’t practice building relationships during the hiring process, you’re showing companies you’re missing the #1 skill they need. Most people who land their first MSL role do so because someone inside the company remembered them, vouched for them, or connected the dots from a networking call.

Networking isn’t a “nice to have.” It’s the audition. It’s how you prove you can create trust and credibility long before you step into a KOL meeting.

💡 Related readings:

• The Real Reason You Don’t Like Networking
• Stop Sounding Boring and Start Speaking Like a Leader
• So You Want to be an MSL - Here’s How to Make It Happen

Bottom line: degrees and applications get you considered. Communication and networking get you hired. That’s exactly what we teach inside the Aspire MSL Program: how to turn your background into credibility, your conversations into opportunities, and your first MSL offer into reality.

More to Come

This is just the start of the 2025 Career Guide to What Is a Medical Science Liaison.

In the next update, we’ll cover:

• MSL vs Senior MSL and more

Got thoughts on what else we should include? We’d love to hear from you. Contact us here or send us a message on LinkedIn; your input might shape the next update of this guide.