Mark Robin Geier

Mark Robin Geier (1948 – March 20, 2025) was an American de-licensed physician and controversial professional witness who testified in more than 90 cases regarding allegations of injury or illness caused by vaccines.

He and his son David Geier are frequently cited by proponents of the discredited claim that vaccines cause autism. Geier's credibility as an expert witness has been questioned in 10 court cases. In 2003, a judge ruled that Geier presented himself as an expert witness in "areas for which he has no training, expertise and experience".

Geier's scientific work has also been criticized; when the Institute of Medicine reviewed vaccine safety in 2004, it dismissed Geier's work as seriously flawed, "uninterpretable", and marred by incorrect use of scientific terms. In January 2007, a paper by the Geiers was retracted by the journal Autoimmunity Reviews. The Maryland State Board of Physicians referred to it as a "sham IRB" that did not meet the requirements of state or federal law. As a professional witness he testified in more than 90 vaccine cases, in support of the view that there is a clear link between thiomersal and autism. In a 2010 decision, the presiding legal authority wrote, "In summary, I conclude that all of the Geier epidemiologic studies are not reliable, and cannot be accorded any weight."

Controversies Mark and David Geier published several speculative articles about a possible link between autism spectrum disorders and vaccines that contain thimerosal, generating some controversy. The American Academy of Pediatrics dispute the conclusion of the Geiers' paper claiming a correlation between thimerosal and autism, and criticized it for "numerous conceptual and scientific flaws, omissions of fact, inaccuracies, and misstatements". but the National Immunization Program found that "during the first visit the researchers conducted unapproved analysis on their datasets and on the second visit attempted to carry out unapproved analyses but did not complete this attempt. This analysis, had it been completed, could have increased the risk of a confidentiality breach. Before leaving, the researchers renamed files for removal which were not allowed to be removed. Had it gone undetected, this would have constituted a breach of the rules about confidentiality." The Geiers filed three U.S. patent applications on the use of Lupron in combination with chelation therapy as a treatment protocol for autism based on the hypothesis that "testosterone mercury" along with low levels of glutathione blocks the conversion of DHEA to DHEA-S and therefore raises androgens which in turn further lower glutathione levels, ultimately providing a connection between autism, mercury exposure, and hyperandrogenism, specifically precocious puberty.

According to expert pediatric endocrinologists, the Lupron protocol for autism is supported only by junk science. Although Abbott Laboratories sells Lupron in the U.S. and cooperated with the Geiers in one of the patent applications, it is no longer pursuing work with them, citing the nonexistence of scientific evidence to justify further research.

When treating an autistic child, the Geiers order several dozen lab tests, costing $12,000: if at least one testosterone-related result is abnormal, the Geiers consider Lupron treatments, using 10 times the daily dose ordinarily used to treat precocious puberty. The therapy costs approximately $5,000 per month. The Geiers recommend starting treatment on children as young as possible, and say that some need treatment through adulthood. and has been accepted as an expert witness in approximately 100 hearings for parents seeking compensation from the National Vaccine Injury Compensation Program for alleged vaccine injuries to their children. In 10 of these cases, "Dr. Geier's opinion testimony has either been excluded or accorded little or no weight based upon a determination that he was testifying beyond his expertise."

Medical licenses revoked On April 27, 2011, the Maryland State Board of Physicians suspended Geier's medical license as an "emergency action", saying he "endangers autistic children and exploits their parents by administering to the children a treatment protocol that has a known substantial risk of serious harm and which is neither consistent with evidence-based medicine nor generally accepted in the relevant scientific community". The board ruled that Geier misdiagnosed patients, diagnosed patients without sufficient tests, and recommended risky treatments without fully explaining the risks to the parents. They also ruled that he misrepresented his credentials, including during an interview with the board. Geier's lawyer, Joseph A. Schwartz III said the basis of the complaint was a "bona fide dispute over therapy", and hoped for a fair hearing to challenge the board's accusations.

The suspension was reaffirmed in May 2011, and upheld on appeal in March 2012 after a full evidentiary hearing before the Office of Administrative Hearings in Maryland. Geier's licenses to practice medicine in the states of Washington, Virginia and California were suspended as well. In June 2012, Geier was charged with violation of the Maryland suspension by continuing to practice medicine without a license. In August 2012, Geier's license was formally revoked by the Maryland State Board of Physicians. On 5 November 2012, the Missouri Medical board and the Illinois Department of Financial and Professional Regulation revoked Geier's license, both citing action taken by the Maryland State Board of Physicians. On April 12, 2013, Geier's last medical license in the United States was revoked by the state medical board of Hawaii.

In 2011, his son David was charged by the Maryland State Board of Physicians with practicing as a licensed physician when he only has a Bachelor of Arts degree in biology, and was fined $10,000 in July 2012.

Personal life Geier and his wife Anne played doubles tennis. Their son David is also an avid tennis player. Anne died of metastatic melanoma at age 67 in 2014. on March 20, 2025 in Jupiter, Florida.