(Senior / Principal) Scientist, Medicinal Chemistry

Capable Labs • San Francisco, CA

3d • Onsite

About The Position

Capable Labs is seeking a Scientist, Medicinal Chemistry to lead medicinal chemistry design and synthesis across therapeutic programs. This role involves deciding which compounds to make and translating SAR and biological data into the next design cycle. The scientist will be hands-on from route selection through purification and characterization, owning the chemistry decisions that improve potency, selectivity, stability, exposure, tolerability, and efficacy. This is an opportunity to join a vibrant, mission-driven team in San Francisco, valuing speed, rigor, excitement, drive, and a strong work ethic. Capable Labs is a place for ambitious, high-integrity people who want to become dramatically better, surrounded by colleagues who care intensely about the work and offer close feedback. Responsibility is earned through contribution, not title alone, with opportunities to own increasingly important problems and earn meaningful scope.

Requirements

• Five or more years of hands-on industry experience in medicinal or synthetic organic chemistry.
• Strong medicinal-chemistry judgment and the ability to use SAR and biological data to decide what to make next.
• Experience owning chemistry end to end, including compound design, route selection, synthesis, purification, characterization, quality control, and biological handoff.
• Deep troubleshooting ability and a high bar for clean experimental execution and documentation.
• Comfort working close to biological readouts and balancing potency, selectivity, stability, exposure, tolerability, efficacy, and practical synthesis.
• The ability to provide technical direction and raise the quality of a program while remaining hands-on.

Nice To Haves

• Peptide experience is helpful but not required.

Responsibilities

• Lead compound design and synthesis across small-molecule, peptide, and peptide-adjacent programs, from target-compound selection through biological handoff.
• Use SAR, in vitro, and in vivo data to prioritize and design next-round compounds.
• Design and execute practical synthetic routes using solution-phase or solid-phase workflows, functional-group transformations, coupling chemistry, protecting groups, and late-stage diversification as appropriate.
• Own synthesis, purification, characterization, quality control, documentation, and preparation of compounds for biological testing.
• Operate and help maintain key chemistry instrumentation, including HPLC, prep HPLC, LC-MS, microwave-assisted synthesis systems, and related analytical or purification platforms.
• Resolve difficult synthetic and analytical issues involving failed reactions, selectivity, side products, solubility, purification, recovery, or instrument performance.
• Partner closely with biology and pharmacology teams to connect chemistry decisions to potency, selectivity, stability, exposure, tolerability, and efficacy.

Benefits

• Generous equity options
• $500+ monthly wellness budget for training, supplements, coaching, recovery, or other tools that help you perform at your best.
• Broad range of medical, dental, and vision coverage options, with Capable covering 100% of the base policy.
• Access to HSA, FSA, and 401K plans.
• Healthy dinners with the team are provided daily.
• Visa sponsorship where appropriate, including O-1, H-1B, J-1, TN, and other employment-based pathways.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed