QuackeryWatch Canadian Quackbusting Since 1998 · Dr. Terry Polevoy MD

Hulda Clark · The Patients · 1993–2009

The Cure for All Cancers — Except Theirs

Hulda Clark's book promised that every cancer was caused by one parasite and could be cured once it was killed. This page is about the people who believed her, and the people who were told they were sick by her machine when they weren't — and about how long it took anyone in authority to act.

By Terry Polevoy, MD · QuackeryWatch.com · A companion to the main Hulda Clark investigation · October 2026

The patients

The best-known case — Patricia Chavez's account of her mother, whose bone tumour grew to two and a half times its size while Clark's clinic told the family it was dead — is told on the main Clark page. These are the others on the record.

Hanne

Denmark · breast cancer · died

Hanne was 42 and single, and her animals were most of her life: five dogs, four cats and birds. After a mastectomy, chemotherapy and radiation she went to a Danish practitioner who used Clark's protocols. He told her he could certainly cure her. He also told her that her pets might be the source of the parasite, so she gave away all but two dogs — which were zapped too — and stopped visiting friends who had animals in case she was “re-infected”. Her mother had to give up bringing her own dogs.

She spent at least $800 on capsules, tinctures and a zapper, changed her food and her soap, and followed the protocol to the letter. The herbs made her vomit and took her appetite. Within about a year the cancer was back in her lungs and liver. The practitioner promised a stronger cure. When she declined the last chemotherapy her hospital could offer, about a week before she died, he told her he was glad, because it would give his treatment a chance. A friend visiting her in hospital found her zapping herself and her dogs. She had an appointment with the practitioner a few days later. She did not live to keep it.

Her friend Pia Johansen sent this account to the site after Hanne's death. What she found hardest to forgive was not the money but the isolation: a dying woman cut off from her animals and her friends on the strength of a theory no parasitologist accepts.

The investigator who was told he had HIV

Indiana · 1993 · not sick

After a former patient complained to the Indiana attorney general, an investigator went to Clark's office posing as a patient. According to the probable-cause affidavit, she told him he had HIV, and that she could cure it in a matter of minutes. He did not have HIV. When Clark learned of the investigation she called her statements a mistake and left the premises two days before an arrest warrant could be served.

A child with spinal muscular atrophy

Tijuana · 2001–2002 · about $30,000

The San Diego Union-Tribune's 2002 series on the Tijuana clinics reported a child with spinal muscular atrophy, an inherited nerve disease, treated under Clark's program for ten months at a cost of about $30,000. There was no improvement. Spinal muscular atrophy has nothing to do with parasites.

A man with a pacemaker

Switzerland · 2004 · heart rhythm disturbance

In 2004 the New England Journal of Medicine published the case of a patient whose cardiac pacemaker was disrupted by a Clark zapper, causing heart-rhythm disturbances. A device sold as harmless electricity turned out to interfere with the one electrical device keeping him well. Nothing in the zapper's marketing warned pacemaker users.

The pattern. Every one of these people either already had a real diagnosis that Clark's method could not treat, or was given a false one by a machine that cannot detect anything. Both errors cost the same thing: money, time, and in the cancer cases, the chance that treatment would still work.

What the authorities did, and when

The death certificate

The certificate registered with San Diego County records what killed her. The immediate cause of death is given as anemia, due to hypercalcemia, with multiple myeloma listed as another significant condition contributing to death. Anemia and a high blood calcium are two of the commonest complications of multiple myeloma, a cancer of the plasma cells in the bone marrow. No autopsy was performed. Her occupation is recorded as “research project leader” in “physiology – medical”. Her ashes were scattered at sea.

The woman whose best-known book was The Cure for All Cancers died with a cancer listed on her death certificate.

Certificate of death for Hulda Regehr Clark, County of San Diego, recording death on 3 September 2009; cause anemia due to hypercalcemia, with multiple myeloma as another significant condition
Certified copy issued by the San Diego County Assessor/Recorder/County Clerk, 12 October 2009, marked “informational”. Social Security number, file numbers, home address and the informant's details have been blacked out by QuackeryWatch. Click to enlarge.

Why this is a Canadian story

Clark was born and educated in Saskatchewan. Zappers were made and sold from Canada. Toronto's Total Health show billed her as a speaker. Canadian patients made the trip to Tijuana. Yet every enforcement action on this page was taken by an American state, the U.S. federal government, or Mexico. No Canadian regulator, prosecutor or court ever took action over her devices or her claims.

Related on QuackeryWatch

Sources

  1. Pia Johansen. Account of her friend Hanne's treatment and death, submitted to and first published on this site.
  2. State of Indiana v. Hulda Clark, probable-cause affidavit, filed 16 August 1993 (reproduced at Quackwatch).
  3. Steve Hinnefeld. “Woman who claims healing knowledge faces charges” and “Clark won't face charges.” Herald-Times (Bloomington, Ind.), 5 and 19 April 2000. Archived on HealthWatcher.net.
  4. Penni Crabtree and Sandra Dibble. “Borderline medicine” series, including the report on Clark's operation and “The 95 percent promise?” San Diego Union-Tribune, 24–25 February 2002.
  5. Associated Press. “Late-stage cancer patients flock to Mexico” (via NBC News): Mexico closed Clark's Tijuana clinic in 2001 for operating without a licence.
  6. Furrer M. et al. “Hazards of an alternative medicine device in a patient with a pacemaker.” New England Journal of Medicine, 2004.
  7. U.S. Federal Trade Commission. Press release on the Dr. Clark Research Association, January 2003; Stipulated Final Judgment, Civ. No. 1:03CV0054 (N.D. Ohio), 18 November 2004.
  8. Joe Schwarcz. “Cure all cancers? Maybe not.” McGill Office for Science and Society, 30 November 2017.
  9. Obituary, San Diego Union-Tribune, 17 September 2009.
  10. State of California, Certificate of Death, Hulda Regehr Clark, County of San Diego; informational certified copy issued 12 October 2009. QuackeryWatch archive.

The practitioner in Hanne's story is not named here: the account is a friend's, and this page relies on it for what happened to Hanne, not for findings about him. Patient names are used only where they were already public or given by the family. Corrections are welcome and are recorded on the page.