International Medical Science Liaison Day2026 · Date · History
The Medical Science Liaison Society identifies 27 March as International MSL Day, states that the first annual activities began on 27 March 2020, and explains that March 27 was chosen because it is the date the Society became a 501(c)(3) nonprofit.
About International Medical Science Liaison Day
International Medical Science Liaison Day, commonly called International MSL Day, is observed on March 27 to recognize medical science liaison professionals.
The Medical Science Liaison Society established the annual day and says activities began on March 27, 2020.
Why International Medical Science Liaison Day matters
The MSL Society’s history page describes March 27, 2020 as the first International MSL Day and says annual campaigns would begin from that date.
The Society explains that March 27 was selected because it is the date the organization became a 501(c)(3) nonprofit. The observance recognizes a professional role; it is not a government holiday and does not create clinical authority beyond an individual professional’s actual responsibilities.
History of International Medical Science Liaison Day
The first International MSL Day was held on March 27, 2020.
The Medical Science Liaison Society is the establishing and current facilitating organization.
March 27 reflects the Society’s nonprofit-registration date.
The project treats “National Medical Science Liaison Awareness and Appreciation Day” as a descriptive legacy alias, not as a separate national observance.
How the observance developed
This timeline uses documented milestones from reviewed sources. Missing stages are left out rather than guessed.
Medical Science Liaison Society
The Society’s own history and launch announcement establish the day.
Medical Science Liaison Society
The Society established the professional-recognition day rather than a government or intergovernmental body.
First documented observance
The Society states that activities and campaigns began on March 27, 2020 and contemporary event material labels that date International MSL Day.
Medical Science Liaison Society
The Society maintains the current International MSL Day programme and history page.
What the evidence establishes
Confirmed institutional roles and milestones are shown first. Details that could not be established from the reviewed sources are listed separately below.
4 fields not established in reviewed sources
Also known as
National Medical Science Liaison Awareness and Appreciation Day, International MSL Day
How to Observe International Medical Science Liaison Day
Recognize MSL colleagues through professional-development, mentoring or educational activities that respect employer policies.
Do not share patient information, unpublished clinical data, internal strategy, customer details or other confidential material in appreciation posts.
Keep disease and medicine discussions evidence-based and within professional/compliance rules; an awareness day is not a substitute for medical advice or regulatory guidance.
Use neutral professional-recognition language rather than implying endorsement of a particular company, medicine or commercial claim.
International Medical Science Liaison Day Facts
International MSL Day is observed on March 27.
The MSL Society says the first edition was March 27, 2020.
The date was selected because March 27 is the Society’s 501(c)(3) nonprofit-registration date.
It is a professional-recognition observance, not a statutory holiday or clinical guideline.
Topic and context
What this page does not assume
- Keep the source-defined country, community, organizer or institutional scope; do not silently broaden it.
- Do not treat the title alone as proof of government recognition or public-holiday status.
- Do not add a creator, founding story or origin claim unless the supporting evidence establishes it.
- Health Information Not Medical Advice.
Evidence & sources
Sources used across the guide are gathered here. Labels show how each source supports the page, and contextual references are kept separate from primary evidence.
Medical Science Liaison Society — official history and event archive
Medical Science Liaison Society — International MSL Day (opens in a new tab)
Professional Society Original Organizer
MSL Society — March 27, 2020 event archive (opens in a new tab)
Professional Society Archive
PR Newswire / MSL Society — first International MSL Day announcement (opens in a new tab)
Organization Release
PR Newswire — organization launch announcement
Understand it, compare it, then explore further
Start with the most common factual questions, then compare closely related observances and explore useful connections.
Frequently asked questions
When is International Medical Science Liaison Day?
27 March The documented recurrence rule is: 27 March.
Does International Medical Science Liaison Day fall on the same date every year?
Yes. It uses a fixed annual date unless stronger evidence changes the pattern.
Is International Medical Science Liaison Day an official public holiday?
The reviewed sources verify it within this scope: International / Medical Science Liaison Society professional-recognition day. That recognition does not by itself make it a statutory public holiday; the site only makes public-holiday claims when reliable evidence explicitly does so.
Who established or recognizes International Medical Science Liaison Day?
The reviewed sources identify Medical Science Liaison Society as the proclaiming or establishing body. Current facilitation or coordination is recorded as Medical Science Liaison Society.
Is International Medical Science Liaison Day international or country-specific?
The documented scope is international or global: International / Medical Science Liaison Society professional-recognition day. That does not mean every country treats the date as a public holiday or observes it in the same way.
How is this page verified?
The factual information is checked against reviewed sources, including the date pattern, scope and institutional history. This page was checked on 2026-09-25.
When is International MSL Day?
It is observed on March 27.
When did it begin?
The Medical Science Liaison Society says annual activities began with the first International MSL Day on March 27, 2020.
Why March 27?
The Society says March 27 is the date it became a 501(c)(3) nonprofit organization.
Who organizes it?
The Medical Science Liaison Society established and continues to promote the observance.
Can appreciation posts include work or patient examples?
Only if they comply with employer, privacy, medical and regulatory rules. Confidential patient, clinical, customer or internal information should not be disclosed.
Other observances on March 27
These observances are also listed on March 27, 2027.
International Whisk(e)y Day
Established drinks-calendar and historical references place International Whisk(e)y Day on March 27; the parenthetical spelling intentionally encompasses whisky and whiskey traditions.
Quirky Country Music Song Titles Day
Wellcat’s first-party holiday calendar lists Quirky Country Music Song Titles Day on March 27; Wellcat’s preserved media coverage identifies Thomas and Ruth Roy as creators of the named day…
World Theatre Day
International Theatre Institute first-party material verifies that ITI initiated World Theatre Day in 1961, that it has been celebrated annually on March 27 since the first 1962 observance,…