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San Francisco, California, United States
Remote only
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.
Loyal is seeking a Senior Principal Scientist, Drug Substance to serve as the technical leader for drug substance process development and manufacturing from early development through commercialization. This high-impact, externally-facing role will drive drug substance process development and manufacturing, and deliver flawless execution across CDMO partners while serving as the internal subject matter expert informing cross-functional decision-making and long-term development strategy across Loyal's growing pipeline.
You will be reporting to our VP of Manufacturing
Salary Range: $175,000 - $230,000
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.
Moonshots, derisked methodically
Bringing the first longevity drug to market is an extremely difficult technical and social pursuit. To achieve this we must take bigger bets than the field has historically made, paired with the technical rigor to de-risk them step by step. We plan on both short and extremely long timescales, and we have the conviction to see our vision through to success or failure.
Opportunity is at the intersection
We lean into combining disciplines, expertise, 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 push back on each other, ask questions instead of issuing orders, and try to prove ourselves wrong. We are emotionally attached to the outcome, not our personal hypotheses, and welcome being challenged instead of treating it as a threat.
High agency, high humility
Most of what we're doing has never been done before, so we can't rely on established precedents to guide our way. We move forward to generate clarity, build strategies resilient to the fact that we don't know what we don't know, and design small experiments where we can fail safely, without jeopardizing the bigger mission.
Lead with transparency and context
We proactively and consistently share the why behind our strategy - not just the what - because we believe sharing context enables great people to make great decisions.
Empathy and respect for all life
Our patients are not just numbers. We deeply respect the value of every life, large and small and take our ethical responsibility to the families we treat extremely seriously.
