The doctors
Materia was founded in 2024 by Dr. Sarah Liang (Stanford-trained pain medicine) and Dr. Marcus Okafor (UCSF-trained palliative care). Every Materia patient is seen by one of them or by a clinical-team physician they have personally trained.
01 · Founding physicians
Co-founder · Pain Medicine
Board cert. Anesthesiology · Pain Medicine
Stanford · UCSF residency · UC Davis fellowship
sarah.liang@materia.health
Sarah completed her medical training at Stanford, her anesthesiology residency at UCSF, and a pain medicine fellowship at UC Davis. She spent six years at a Bay Area pain clinic, where she increasingly saw patients asking about cannabis as an adjunct to existing therapies — and increasingly noticed that the standard answer (a five-minute referral to a card-mill telehealth provider) was failing those patients. Materia is the practice she wished she could refer them to.
Chronic neuropathic pain, fibromyalgia, post-surgical pain management. Particular interest in opioid-sparing protocols where cannabis serves as an adjunct in carefully selected patients.
California Society of Interventional Pain Physicians (member). Co-author, “Cannabis in opioid-sparing protocols: a structured framework” (Pain Medicine, 2024). Speaker, ASIPP Annual Meeting 2025.
Co-founder · Palliative Care
Board cert. Internal Medicine · Palliative Care
Howard University · UCSF residency · Sloan Kettering fellowship
marcus.okafor@materia.health
Marcus completed his medical training at Howard University, his internal medicine residency at UCSF, and a palliative care fellowship at Memorial Sloan Kettering Cancer Center. He spent five years at UCSF’s palliative care service before co-founding Materia. His clinical interest is the supportive care of oncology patients — nausea control, cachexia, treatment-related sleep disturbance, and end-of-life comfort care.
Oncology supportive care, palliative medicine, end-of-life comfort care. Coordinates closely with treating oncologists at UCSF, Stanford, and California Pacific Medical Center.
American Academy of Hospice and Palliative Medicine (fellow). Lead author, “Adjunctive cannabinoid use in advanced-cancer cachexia” (Journal of Pain & Symptom Management, 2023).
02 · How the founding physicians practice
No nurse practitioners or physician assistants conducting the initial consultation. Both Sarah and Marcus take this position because the medical decision-making in a cannabis consultation — including the decision not to certify — benefits from a board-certified physician.
Each care plan is reviewed and signed by the prescribing physician. No templates rubber-stamped at scale. The patient’s name, condition, and protocol appear in the physician’s own handwriting on the printed copy.
Materia patients have access to a secure clinical messaging channel staffed by the practice during business hours. For urgent matters between visits, the physician responds within four business hours.
03 · The practice, in five years
2022
Sarah and Marcus, then colleagues at UCSF, agreed they were both seeing patients fail in the existing medical-cannabis system. The first draft of the Materia protocol was written on a hospital cafeteria napkin.
2024 · Q1
Filed as a California Professional Corporation. CA medical license obtained. Initial DEA / state cannabis-certification authorization in place.
2024 · Q3
Hayes Valley clinic opened with one exam room. The first patient was a 68-year-old retired teacher with chronic neuropathic pain referred by her primary care physician at UCSF.
2025 · Q2
HIPAA-compliant platform operational. California-only initially. Expanded to New York and Florida by end of year following multi-state licensing approvals.
2025 · Q4
All board-certified, all trained directly by Sarah and Marcus in the Materia clinical protocols. The practice now sees patients across all five condition programs.
2026 · Q1
Materia’s internal evidence matrix — reviewed and updated each quarter — is now made publicly available to referring physicians on request.
04 · For referring physicians
Materia operates as a specialty referral, not a parallel care provider. Every Materia patient’s care plan is shared (with the patient’s authorization) with the referring physician within 72 hours of the initial consultation.
If you are a primary care physician, pain specialist, oncologist, neurologist, or palliative-care provider with patients who are considering cannabis as part of their treatment, the workflow is:
Materia operates a referring-physician program offering quarterly evidence briefings, joint case conferences, and direct access to our clinical team. There is no fee.
Contact · physicians@materia.health
Join the physician programFrom San Francisco
Book a consultation with Dr. Liang, Dr. Okafor, or a member of our clinical team.