Medical affairs is one of three core divisions inside a pharmaceutical company, sitting alongside research and development (R&D) and the commercial (sales and marketing) arm. Its central purpose is to serve as the scientific bridge between the company and the outside world: doctors, researchers, patient groups, insurers, and policymakers. Unlike the sales team, which promotes products, medical affairs provides unbiased, evidence-based scientific information and brings external insights back into the organization to shape strategy.
How Medical Affairs Fits Into a Pharma Company
For years, medical affairs operated as a support function, handling scientific questions that didn’t neatly fit into R&D or sales. That has changed significantly. Industry groups and major consulting firms now describe medical affairs as a “third strategic pillar” equal in importance to R&D and commercial operations. The COVID-19 pandemic accelerated this shift, as healthcare systems demanded faster scientific communication, real-world data on treatments, and closer collaboration between pharma companies and clinicians.
The division’s independence from sales is not just cultural, it’s regulatory. The FDA requires that responses to medical questions, particularly those involving uses not listed on a drug’s approved label, come from medical or scientific personnel who operate independently from sales and marketing departments. This separation, sometimes called the “commercial firewall,” is fundamental to how medical affairs functions day to day.
Core Responsibilities
Medical affairs teams handle a broad set of activities that generally fall into four categories.
Scientific communication. Teams share clinical evidence with doctors, patient advocacy groups, insurers, and policymakers. This includes safety updates, published research, educational programs, and responses to specific medical questions from clinicians. When a doctor asks about using a drug for a purpose not on its approved label, medical affairs is the only group within the company allowed to respond, and those responses must be truthful, balanced, and accompanied by the drug’s official labeling and safety information.
Gathering external insights. Medical affairs professionals spend significant time in the field talking with physicians, researchers, and patient groups. They bring back information about unmet medical needs, how treatments perform in everyday practice, and what gaps exist in available data. These insights directly inform the company’s decisions about research priorities, educational programs, and overall strategy.
Generating real-world evidence. Beyond the controlled clinical trials that R&D runs to get a drug approved, medical affairs teams lead or support studies that examine how a treatment performs in routine clinical practice. This real-world evidence has become increasingly important for regulatory bodies, insurers, and health systems making coverage and reimbursement decisions. Medical affairs also supports investigator-sponsored studies, where outside researchers propose and lead their own research using the company’s product.
Demonstrating value to payers. A growing part of medical affairs involves health economics and outcomes research. This work quantifies a treatment’s value, not just whether it works clinically, but whether it delivers meaningful outcomes relative to its cost. Governments, insurance companies, and hospital systems rely on this evidence when deciding which treatments to cover.
The Medical Science Liaison Role
The most visible role in medical affairs is the medical science liaison, or MSL. These are field-based scientists who build relationships with leading physicians and researchers in a specific disease area. Unlike sales representatives, MSLs do not carry sales targets or promote products. Their conversations focus on the underlying science: disease biology, clinical trial data, treatment landscapes, and unmet needs.
MSLs proactively meet with medical experts to understand what clinical challenges they face and whether there’s interest in scientific collaboration. They deliver presentations on disease states and clinical evidence, support advisory boards, and help identify potential investigators for clinical studies. All of their interactions must remain non-promotional, factual, and grounded in published evidence. For drugs still in development, MSLs can discuss pre-approval information, but only within strict boundaries that reflect the product’s investigational status.
How Success Is Measured
Because medical affairs operates independently from sales, it doesn’t use revenue or prescription volume as performance metrics. A global survey of MSL performance measurement found that the most commonly tracked quantitative metrics are the number of engagements with key medical experts (used by 92% of organizations), the number of actionable insights submitted back to the company (53%), and the number of expert relationships maintained over time (51%). About half of organizations also track scientific presentations delivered and clinical trials supported.
On the qualitative side, the most valued measures are the quality of relationships with physicians (preferred by 70% of respondents), the quality of insights gathered from the field (67%), and whether interactions actually expanded a doctor’s scientific understanding of a disease or treatment (63%). Feedback from the physicians themselves ranks highly as well, with 62% of organizations considering it a preferred metric. This emphasis on relationship quality and insight generation reflects the function’s core identity: it succeeds by improving scientific understanding, not by driving prescriptions.
Who Works in Medical Affairs
Medical affairs roles typically require advanced scientific or clinical training. Most companies hire people with terminal degrees: MDs, PharmDs, or PhDs. For field roles like MSLs, deep expertise in a therapeutic area matters as much as the credential itself, since these professionals need to hold peer-level scientific conversations with specialist physicians.
Several board certifications exist for medical affairs professionals. The Board Certified Medical Affairs Specialist (BCMAS) credential is currently the only program fully accredited by globally recognized bodies. MSLs can pursue a dedicated MSL board certification, and pharmacists sometimes hold the Board-Certified Pharmacotherapy Specialist credential. These certifications are not universally required but signal expertise and are increasingly common as the field professionalizes.
Digital Tools and Data Analytics
Medical affairs is moving toward data-driven, digitally integrated engagement. Companies are adopting AI-powered analytics to process real-world evidence, scan competitive intelligence from external publications, and determine the “next-best action” for field teams, meaning the most useful scientific interaction to have with a given physician at a given time. Natural language processing is being used in medical information centers to handle scientific inquiries more consistently across markets, so that doctors can access the information they need on demand.
The broader shift is from thinking about individual touchpoints (a single meeting, a single email) to planning the entire engagement journey with a physician or healthcare system. Companies that do this well tailor their scientific communications across in-person meetings, virtual interactions, digital content, and conference engagements, creating a coordinated experience rather than fragmented, one-off contacts. Digital tools are replacing many face-to-face interactions, particularly for routine information exchange, while in-person engagement is being reserved for deeper scientific discussions and relationship building.