David Geier

David Geier was born around 1980 and graduated from the University of Maryland, Baltimore County with a Bachelor of Arts degree in biology in 2002. He never attended medical school or any health professions program. From an early age he was drawn into his father Mark Geier's autism-vaccine research enterprise, where despite holding no clinical credentials he was listed as co-author on dozens of papers and participated directly in patient care.

The Maryland Board of Physicians charged David Geier on May 16, 2011, with practicing medicine without a license, alleging that he diagnosed a patient, determined which blood tests to order, and ordered those tests. An administrative law judge initially recommended dismissing the charges, but the Board rejected this recommendation in July 2012, imposed a $10,000 fine, and the decision was upheld by the Circuit Court for Montgomery County in 2014. Simultaneously, his father's medical licenses were being revoked across multiple states for conducting the same Lupron protocol that David had actively participated in administering.

David Geier co-authored papers advancing the discredited 'testosterone-mercury' hypothesis with his father through the mid-2000s to early 2010s, publications that provided an aura of scientific legitimacy to the expensive and harmful Lupron treatments their clinics charged to families of autistic children. His role illustrates how pseudoscientific medical enterprises can rely on non-physicians performing clinical functions under a licensed practitioner's cover.

In 2025, David Geier was appointed to lead an autism study at the Department of Health and Human Services under the administration of Robert F. Kennedy Jr. The Autistic Self Advocacy Network and numerous scientists publicly objected to the appointment, citing his history of practicing medicine without a license and his role in the discredited Lupron protocol.

“Co-author of research claiming thimerosal in vaccines causes autism and that the Lupron protocol treats autism.”

David Geier has no medical training to qualify him to conduct or interpret clinical research on patients. The studies he co-authored with his father were criticized by the AAP for scientific flaws, and courts found them unreliable. The Lupron protocol they promoted has no scientific basis.

“As a 'researcher' he is qualified to conduct diagnostic evaluations and order medical testing for autistic children.”

The Maryland Board of Physicians found that Geier, who is not a physician, diagnosed a patient and ordered blood tests—acts constituting the practice of medicine. He was fined $10,000 and the board upheld the finding on appeal.