METHUSELAH ARCHIVE INTERVENTIONS / LAETRILE (AMYGDALIN, MARKETED AS "VITAMIN B17")

Laetrile (Amygdalin, marketed as "Vitamin B17")

oral · 1920–present
category:oral
delivery:Historically administered by intravenous or intramuscular injection in clinics, followed by oral tablets for maintenance; today administered at clinics in Mexico and some U.S. clinics, and sold as bitter apricot-seed products.
price tier:not classified
era:1920–present
current status:both
regulatory:banned
SHORT PITCH (AS SOLD)
Oral amygdalin was tried and abandoned against cancer in the early 1920s. Laetrile was a later semisynthetic derivative promoted as an anticancer drug and labeled 'Vitamin B17.'
THE ACTUAL EVIDENCE
No controlled clinical trial has ever shown a benefit. The NCI's own 1978 retrospective review of the strongest case reports its proponents could supply found no definite evidence of anti-cancer activity. A 1982 NCI-sponsored clinical trial (Moertel et al., New England Journal of Medicine) found no substantive benefit in 175 evaluable patients -- no cures, no tumor shrinkage beyond a single temporary partial response, no extension of survival, and several cases of cyanide toxicity. A 2011 Cochrane systematic review concluded that benefit claims were not supported by sound clinical data and that the risk-benefit balance is unambiguously negative given the risk of cyanide poisoning. The FDA has never approved laetrile or amygdalin for any use and continues to issue safety warnings against amygdalin-containing apricot-seed products as recently as May 2024.
PRACTITIONERS
INGREDIENTS
CASES
CLAIMS
SOURCES
  1. A Clinical Trial of Amygdalin (Laetrile) in the Treatment of Human Cancer (1982)
  2. Special Report on Laetrile: The NCI Laetrile Review. Results of the National Cancer Institute's Retrospective Laetrile Analysis (1978)
  3. Laetrile Treatment for Cancer (2011)
  4. Laetrile for Cancer: A Systematic Review of the Clinical Evidence (2007)
  5. Pharmaceutical Assessment of Amygdalin (Laetrile) Products (1978)
  6. The Unitarian or Trophoblastic Thesis of Cancer (1950)
  7. Laetrile/Amygdalin (PDQ) - Health Professional Version (2022)
  8. United States v. Rutherford, 442 U.S. 544 (1979) (1979)
  9. Amygdalin (2021)
  10. FDA Issues Warning About Toxic Amygdalin Found in Apricot Seeds (2024)
  11. Medicine: Laetrile Crackdown (1976)
  12. Laetrile (1977)
NOTES

Laetrile is the U.S.-patented, semisynthetic form (mandelonitrile-beta-glucuronide) of amygdalin, a cyanogenic compound naturally present in apricot, peach, and bitter almond kernels; the version manufactured in Mexico and sold there since the 1970s uses a related but chemically distinct form (mandelonitrile beta-D-gentiobioside) derived directly from crushed apricot pits. Promoters advanced several distinct rationales: one held that cancer resulted from deficiency of a missing “Vitamin B17”; another held that cyanide released from laetrile selectively killed malignant cells. After doctors abandoned oral amygdalin as too poisonous in the early 1920s, biochemist Ernst T. Krebs Jr. promoted a semisynthetic derivative beginning in the early 1950s; TIME reported in 1976 that the cross-border laetrile industry was supplying an estimated 10,000 patients a day. The U.S. Food and Drug Administration has never approved it; a National Cancer Institute-sponsored clinical trial published in 1982 found no substantive benefit, and it remains commercially available today and is administered at clinics in Mexico and some U.S. clinics.