Written by Adele Stapf, Helen Cooke, Helen Seers and the CAM-Cancer Consortium.
Updated February 8, 2017


Does it work?

Use as anti-cancer therapy

Systematic reviews

The authors of a 2015 Cochrane systematic review were unable to find any randomised controlled trials assessing the effectiveness of laetrile. They concluded that there was no evidence that laetrile was effective as an anti-cancer agent.6

Clinical trials

Two clinical trials have been conducted using amygdalin/laetrile:

In the first uncontrolled study (phase I;  n = 6) amygdalin was applied intravenously at a dosage of 4.5  g/m2 body surface followed by oral administration of  0.5 g three times daily.7 Additionally, patients took a combination of several vitamins and enzymes and followed a diet. Two of the six tumour patients studied developed symptoms of cyanide poisoning while they were taking oral amygdalin. No indications of clinical effectiveness were found.

The second clinical trial (phase II; n = 175) compared the above amygdalin dosage regimen versus a “high-dose group” (7 g/m2 body surface i.v. for 21 days followed by 0.5 g four times daily). Also the adjunct treatment programme comprising vitamins, dietary guidelines and enzymes differed in terms of the dosages used. One participant showed a decrease in tumour size.8

Observational studies and case series

No observational studies and case series allowing conclusions about the effectiveness and efficacy of amygdalin are available.


Adele Stapf, Helen Cooke, Helen Seers, CAM-Cancer Consortium. Amygdalin/Laetrile [online document]. http://cam-cancer.org/The-Summaries/Dietary-approaches/Amygdalin-Laetrile. February 8, 2017.

Document history

Assessed as up to date in February 2017 by Barbara Wider.

Updated and revised in July 2015 by Adele Stapf.
Updated in April 2014 by Barbara Wider.
Assessed as up to date in December 2012 by Helen Cooke.
Most recent update and revision in December 2011 by Helen Cooke.
Fully revised and updated in July 2009 by Helen Cooke.
Summary first published in September 2005, authored by Helen Seers.


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