About Loyal

Loyal is a clinical-stage veterinary medicine company developing longevity drugs for dogs. Our mission is to help dogs live longer, healthier lives.

We're pioneering a new category of veterinary prescription drugs that proactively and preventatively target the underlying drivers of aging, delaying the onset of disease and preserving quality of life as dogs age. We've already made significant progress in our mission to develop the first FDA-approved drugs to extend canine lifespan: as of early 2026 we've completed two of three major FDA review sections for our lead program, LOY-002, and are targeting submission of the third and final section later this year.

Loyal is a well-funded startup with teams of scientists, veterinarians, engineers, operators, and creatives. You'll help us continue on our path of earning FDA approval for the first lifespan extension medicine for any species — and change what's possible for the dogs we love.

About the role

The Senior Principal Scientist will serve as the technical authority and strategic leader for drug product development. This role is responsible for defining and driving formulation and manufacturing strategy from preclinical development through early clinical stages, ensuring technical excellence, regulatory alignment, and execution across external partners.

This individual will act as the internal subject matter expert for drug product CMC, influencing cross-functional decision-making and shaping long-term development strategy.

You will be reporting to our VP of manufacturing.

Your daily work will include

• Own and lead the end-to-end drug product development strategy, including pre-formulation, formulation development, scale-up, and clinical manufacturing.
• Serve as the technical lead for all drug product activities with CDMOs, including selection, oversight and troubleshooting
• Provide strategic guidance on raw material sourcing, manufacturability, product quality risk assessments, and lifecycle management considerations.
• Identify and proactively mitigate technical, regulatory, and supply risks; develop contingency strategies to ensure program continuity.
• Author, review, and approve drug product CMC sections for regulatory submissions (IND/CTA and amendments), and represent Drug Product CMC in regulatory agency interactions.
• Lead technical due diligence efforts, including CDMO evaluation, proposal review, data integrity assessments, and master batch record approval.
• Establish and implement robust experimental strategies, including design of experiments (DoE), to optimize formulation and process development.
• Mentor and provide scientific leadership to internal team members and consultants; elevate organizational capabilities in drug product development.
• Lead process readiness activities for Pre-Approval Inspections (PAIs), ensuring manufacturing processes, documentation, validation packages, and technology transfer records are inspection-ready and aligned with regulatory expectations

About you

• Ph.D. in Material Science, Chemical Engineering, or related physical science.
• 10+ years of industry experience in preferably small molecule oral solid dosage formulation development, with demonstrated ownership of drug product strategy through clinical stage development.
• Proven experience leading development of novel molecular entities.
• Significant experience selecting, managing, and overseeing CDMOs for formulation development, technical transfer, scale-up, and GMP manufacturing.
• Deep expertise in preferably small molecule oral tablet formulation, process development, compaction fundamentals, and manufacturing science.
• Demonstrated experience authoring and defending CMC regulatory submissions.
• Significant hands-on experience designing and executing statistically sound development programs using DoE and data-driven decision frameworks.
• Experience supporting technical diligence and external partnership evaluations.
• Veterinary dosage form experience preferred but not required.
• Demonstrated ability to operate effectively in a dynamic, fast-paced startup environment.

Salary Range: $175,000 - $230,000

Loyal benefits

• Full-coverage health insurance — medical, dental and vision — for you and your dependents
• $1,000 home office equipment stipend
• $1,200/year learning budget for books, courses, etc.
• $250/month wellness budget for gym, cleaners, spa, food, etc.
• All 3-day weekends are turned into 4-day weekends 🎉
• Unlimited vacation and paid holidays
• Paw-ternity leave — adopt a dog and get a day off with your new family member 🐶
• Competitive salary
• Company equity options grant for new hires

Loyal is founded and led by a first-gen female CEO and is proud to be an equal opportunity employer. We do not discriminate against applicants based on gender, race or color, ethnicity or national origin, age, disability, religion, sexual orientation, gender identity or expression, veteran status, or any other applicable characteristics protected by law.

Our values

Lean into moonshots

We don’t settle for incremental change. We have the bravery to take risks and shoot for the impact we want to have.

Opportunity is at the intersection

We lean into combining disciplines, expertises, and perspectives not normally adjacent. We design our organization to facilitate cross-pollination and cross-collaboration. We reject silos.

Expertise without ego

Titles do not determine who has a voice. We work on hard technical problems and have a ton of fun while at it.

Learning by doing

Our path is novel and many things we are doing have never been done before. We lean into MVPs and are open to unexpected outcomes.

Lead with context

We value leading with context. We equip people with the context and background necessary to make their own decisions and act in the best interest of Loyal. We empower teams to succeed.

Empathy and respect for all life

Our patients are not just numbers. Our work is intentional, thoughtful, and guided by respect for life. We take our responsibility to pets and pet parents seriously.