top of page

Amygdalin / Laetrile / Vitamin B 17: An Almost Forgotten Cancer Treatment

James Odell, OMD, ND, LAc

Pits from almonds and apricots amygdalin

For thousands of years various civilizations recognized the health benefits of amygdalin by consuming apricot and almond pits. 

Unfortunately, amygdalin, also known as Laetrile or vitamin B17, was banned by the U.S. FDA as a cancer treatment in 1979 and labeled as a “flunk” by Time Magazine after the National Cancer Institute conducted a flawed study. 

Nevertheless, amidst challenges and controversy, the pharmacological promise of amygdalin persists as scientists tenaciously pursue research into its potent anti-cancer properties.

Editor's Note: This article is a less technical and condensed version of “Amygdalin and Laetrile – History and Current Usage” published February 7, 2020.

What is Amygdalin?

Amygdalin is a type of chemical found in the pits of various fruits and in several plants from the Rosaceae family, like peaches, apricots, and bitter almonds. It falls into the category of cyanogenic glycosides, which are defense chemicals in plants. These compounds are widespread in the plant kingdom, including many plants that people commonly eat.

The properties of amygdalin from bitter almond seeds were first explained by German chemists Liebig and Wohler in 1837, following its isolation seven years earlier by French chemists Pierre-Jean Robiquet and A. F. Boutron-Charlard.

The Rediscovery of Amygdalin

In 1920, a California physician named Dr. Ernst Theodore Krebs, Sr., rediscovered amygdalin. His son, Dr. Ernst Krebs, Jr., later developed it into a compound called "Laetrile or B17" through additional research. 

Both amygdalin and its patented form, Laetrile, have been marketed as "vitamin B-17," even though technically neither is a real vitamin. Dr. Ernst Krebs, Jr. also referred to it as B17 because he advocated for its daily consumption. Laetrile, an acronym for "LAEvo-rotatory mandeloniTRILE beta-diglucoside," is a purified, semi-synthetic version of amygdalin with a different structure.

The term "Laetrile" with a capital "L" typically refers to the original product created by the Krebses, patented for its purification process. 

On the other hand, "laetrile" with a lowercase "l" usually refers to the commercial form of amygdalin, which is likely a mix of left and right-turning forms. 

The Krebses believed that only the left-turning form of Laetrile was effective against cancer. 

They patented the purification process for their original product. However, the commercial form may contain both forms, which the Krebses considered less effective for cancer therapy.

Inexperienced extraction, improper packing, or storage can cause natural amygdalin, which has a right-turning configuration, to transform into the unnatural form, neoamygdaline.

Ernest Krebs and a quote about vitamin b17 and cancer

Where Is Amygdalin Found Naturally?

Cyanogenic glycosides, like amygdalin and prunasin, are found in more than 1000 plant species and are therefore present in animals that consume those plants. 

These compounds are common in the Rosaceae family, especially in plants like apricot, cherry, apple, peach, and others. They're also found in nuts (macadamia, bitter almond, walnuts), beans (Burma, broad, lentils, mung, Lima, scarlet runner, Rangoon), berries (blackberry, elderberry, raspberry, cranberry, strawberry, chokeberry), grasses (wheat grass, acacia, alfalfa, milkweed, Sudan, white Dover), and seeds (flax, chia, sesame).

Traditional and Cultural Uses of Amygdalin

Many plants rich in amygdalin have been integral to traditional diets and medicinal practices across cultures for centuries. For example, bitter almonds and apricot kernels have long been utilized in traditional Chinese medicine (TCM) to promote lung and large intestine health, alleviate coughs, and regulate bowel function. Additionally, apricot seed oil has traditionally served as a laxative, while bitter almonds in TCM were historically employed to address issues like blood stagnation, abscesses, and tumors.

Over a century ago, amygdalin from bitter almonds and apricot kernels was utilized in cancer treatment, gaining popularity as an alternative cancer therapy in the U.S. by the 1970s. By 1978, an estimated 70,000 U.S. cancer patients had used amygdalin and its purified, semi-synthetic form Laetrile and to treat their cancer. Despite this, Laetrile (amygdalin) has not received approval from the FDA for use in cancer treatment.

People often consume amygdalin through apricot kernels, which are similar to almonds but softer and not as sweet. The bitterness of apricot, almond, or peach kernels indicates their amygdalin content – the more bitter, the more amygdalin. Both sweet and bitter almond varieties contain amygdalin, but apricot kernels can vary in amygdalin content, so it's essential to find a reliable source for consistency.

Cyanogenic Glycosides Serve as Plant Defenses

Cyanogenic glycosides, including amygdalin and prunasin, serve as plant defenses against grazers, protecting seeds and fruit. These compounds also play roles in germination, bud formation, carbon and nitrogen transport, and potentially act as antioxidants. The production of cyanogenic glycosides is an evolutionarily conserved function, observed in species ranging from ferns to more recent angiosperms.

Safety Considerations

Cases of death from eating apricot kernels are extremely rare, and I found only three reports, all involving children. These incidents, often cited in anti-Laetrile materials, include a report by Sayre and Kaymakcalavu (1964) stating that two children in Central Turkey died from cyanide poisoning between 1957 and 1962 after consuming apricot kernels. Lasch and Shawa (1981) reported two more child deaths in Gaza, where one group had been "feasting on apricot kernels," and another had eaten a sweet made from the kernels. In 2011, a 28-month-old girl in Turkey allegedly died after eating ten apricot kernels. However, these cases provide limited information on the lethal dose of apricot kernels, and notably, only instances from Turkey and Gaza are reported as fatalities in professional literature.

*People have consumed plants with cyanogenic glycosides, like apricot kernels, for thousands of years.

Despite tens of thousands worldwide purchasing and presumably consuming apricot kernels, reports of toxicity are rare in professional literature. This raises questions about the rarity of reports, especially when anti-Laetrile groups are eager to highlight the few that exist. The financial and patent-related motives of the pharmaceutical industry may be influencing the perception of apricot kernel toxicity, contrasting with well-established but toxic cancer treatments.

Side Effects of Amygdalin-Rich Foods

While consuming amygdalin-rich foods can have potential health benefits, overeating seeds or kernels may lead to side effects such as nausea, vomiting, headache, and malaise. It is crucial to consume them in biologically reasonable amounts under the guidance of a healthcare professional. Laetrile and amygdalin products may vary in strength, purity, and safety, and effects should be monitored. Individuals with medical conditions should consult healthcare providers before starting new therapies and seek immediate medical attention if experiencing side effects.

Laetrile Production

Laetrile, derived from apricot kernels, is primarily produced in Mexico using ground kernels imported from California. The extraction process involves removing fat from the ground kernels using solvents like ether or alcohol. Approximately 33 kernels are needed for a 500-mg tablet, and 200 kernels are required for 3g of the injectable form.

Anticancer Mechanisms

Several anticancer mechanisms of amygdalin have been proposed. One hypothesis involves beta-glucosidase (β-glucosidase) activity, an enzyme upregulated in cancerous cells. Amygdalin, containing two glucose molecules, is metabolized by cancer cells, releasing benzaldehyde and hydrocyanic acid, causing apoptosis or cell death in cancer cells. This process is facilitated by β-glucosidase, which acts as the unlocking enzyme for amygdalin molecules. The liver's detoxification function neutralizes free cyanide molecules by combining them with sulfur, rendering them harmless.

Another hypothesis suggests orally consumed amygdalin is metabolized to mandelonitrile, transported to hepatic tissues, transformed to a beta-glucuronide compound, and further catabolized by β-glucuronidases in neoplastic cells, liberating mandelonitrile and hydrogen cyanide.

A third hypothesis proposes that a cancerous condition may result from an amygdalin (vitamin B-17) deficiency. This theory suggests steady dietary administration of B-17 from certain fruit pits could prevent cancer, categorizing amygdalin and Laetrile as nutritional supplements rather than drugs.

An additional proposed mechanism involves glutathione metabolism. The release of cyanide and benzaldehyde into tumors depletes their glutathione, disrupting cellular processes and potentially inducing apoptosis in cancer cells. 

Despite these proposed mechanisms, more research is needed to fully understand the anticancer properties of amygdalin.

Amygdalin – Laetrile Controversy and Politics – Forbidden Fruits

If the cancer fighting potential of amygdalin and its purified, semi-synthetic form Laetrile was truly ineffective, there would be no controversy. 

Amygdalin, while possessing potential anticancer properties, has not been successfully developed into a patentable and profitable drug by pharmaceutical companies, unlike other plant-derived agents such as: 

  • taxol and vinca alkaloids from the Pacific yew tree were patented to create the chemotherapy agent’s taxol and paxataxol.

  • toxic vinca-alkaloids have been patented from Madagascan periwinkle (Catharanthus roseus) to create the chemotherapy agent’s vinblastine and vincristine. 

  • podophyllotoxin has been patented from May apple’s toxin (Podophyllum peltatum) to create the chemotherapy drugs, etoposide and teniposide.

  • rastuzumab emtansine (Kadcyla) is an antibody conjugated to a synthetic toxic derivative of the Ethiopian plant Maytenus ovatus. It is used to treat leukemia, breast, and lung cancers.

All are very profitable, patented cytotoxic agents.

Forty Plus Years of Controversy

Proponents of amygdalin consider it a natural cancer remedy for both prevention and treatment of cancer, while opponents warn that amygdalin and Laetrile is ineffective and toxic. This whole issue of amygdalin has been clouded by the forty-plus-year-long Laetrile controversy. 

To fully appreciate how Laetrile was blacklisted by the FDA, it is first necessary to understand the research trial that originally condemned it. Basically, the overall Laetrile controversy is not one of science, it is political, and involves big business. Only a few other areas of medicine, like stem cell research, have been polarized as much as the pros and cons of Laetrile.

Promising Results at the Sloan-Kettering Institute

Due to the promising outcomes seen by doctors using amygdalin extracts like Laetrile to treat cancer, research on Laetrile began at the Sloan-Kettering Institute. In the years 1972 to 1973, Dr. Kanematsu Sugiura, an experienced cancer researcher, conducted experiments to assess the effects of injectable amygdalin extracts on mice with mammary tumors. Dr. Sugiura found that mice treated with amygdalin had a lower rate of metastases compared to untreated mice. Specifically, about 20% of the treated mice developed metastases, whereas approximately 80% of the untreated mice did. Dr. Sugiura repeated these studies multiple times and consistently observed a reduction in metastases among the treated mice.

Despite these promising results, Dr. Sugiura's findings were not published, and he faced criticism and eventual dismissal from Sloan-Kettering Institute after sharing his results with superiors. Subsequently, a book titled, The Anatomy of A Cover-up, was written about Dr. Sugiura's research.  This book includes statistical data from Dr. Sugiura's experiments, which demonstrate the benefits of amygdalin. In the book, Dr. Sugiura emphasized that amygdalin significantly inhibited the development of lung metastases in mice with mammary tumors and inhibited the growth of the primary tumor.

Dr. Kanematsu Sugiura, Laetrile Researcher

Dr. Kanematsu Sugiura, Laetrile Researcher - from a documentary about a cover-up involving what seemed to be a promising new cancer treatment in the 1970s.

The NCI Studies

In 1981, the National Cancer Institute (NCI) conducted clinical trials on "laetrile" at the Mayo Clinic, sponsored by the NCI. The phase I study focused on dosage and toxicity, while the phase II study involved treating 178 patients with advanced cancers using "laetrile" along with a metabolic therapy program consisting of diet, enzymes, and vitamins. The trial did not include a control group and did not aim to determine if "laetrile" increased lifespan or improved well-being. The conclusion was that "laetrile" is a toxic drug and not effective as a cancer treatment.  This trial received widespread attention, and its results were considered definitive.

Challenging the Validity of the Research Studies

However, in the following years, some doctors and scientists questioned the trial's validity. 

Journalist Michael L. Culbert, a member of the Laetrile Advocacy Group Committee for Freedom of Choice in Cancer Therapy, criticized the trial, stating that it did not use pure amygdalin and that the "laetrile" used was a degraded form.  In his book Freedom from Cancer: the Amazing Story of Vitamin B-17, or Laetrile, Dr. Culbert wrote that “The (NCI) laetrile clinical trial wound up being, in essence, a U.S. government sponsored test of an uncertain laetrile product, whose application was in the hands of doctors and scientists known to be or assumed to be hostile to laetrile, whose patients were anonymous, and the test results of which, being coded, could not be individually released or cross-checked. Worse, the patients accepted for entry into the program were variously described as "terminal" or beyond hope of cure by conventional means."

Book cover Freedom From Cancer

In addition, Dr. Krebs Jr. argued that this artificial form was less than 50% as effective as the pure form. Krebs wrote that the degraded form “caused unpredictable, often severe, reactions in our patients” and that “all of our successful therapeutic studies were conducted using only pure natural amygdalin”.

It is important to be aware that the amygdalin molecule which naturally occurs in hundreds of edible seeds and plants, is considerably unstable during and after extraction from its natural source. Slight variations in the extracting procedure can cause the amygdalin molecules to change to a form unknown to nature. 

The FDA Bans Laetrile

After the trial, Time Magazine ran an article titled "Laetrile flunks," and the FDA imposed sanctions against the sale of Laetrile, claiming lack of evidence for its safety and effectiveness. FDA regulations made amygdalin manufacture and extraction illegal. The U.S. government banned Laetrile transport and use in states without specific laws allowing it, leading to prosecutions for Laetrile transport. 

Additional FDA Regulations

Additionally, FDA regulations made amygdalin manufacture and extraction illegal. The U.S. government also banned the transport of Laetrile into the U.S. or across state lines, as well as the use of Laetrile in states without laws specifically allowing it. 

Since 2000, there have been several instances of prosecution because of Laetrile transport across state lines. Even Dr. Ernst Krebs, Jr. and his secretary served six months in the San Francisco County Jail in 1983 for their continued promotion of Laetrile. 

Today, it is still almost taboo to talk about Laetrile. According to the FDA, the ban on Laetrile was due to risk of side effects. It’s interesting that there isn’t a similar controversy over the dangerous cytotoxic anthracyclines known to cause cardiac failure and fatalities every year. To understand politics is to understand finances.

Recent Amygdalin and Laetrile Research

Fortunately, controversy has not stopped research and truth cannot be hidden indefinitely. Many subsequent foreign studies have confirmed Dr. Sugiura’s work, supporting his conclusion that Laetrile shows potential in reducing the metastatic potential of cancer, although it is not a cure. 

There have been numerous in vitro amygdalin studies over the last decade showing positive anticancer effects on many different cancer cell lines - human colon cancer cells, prostate cancer cells, liver cancer cells, cervical cancer cells, bladder cancer cells, and non-small cell lung cancer cells. 

A 2016, an in vitro study showed that amygdalin induces apoptosis and inhibits adhesion of breast cancer cells. The researchers concluded that the results suggest a potential application of amygdalin as a chemo preventive agent to prevent or alleviate progression of breast cancer, especially triple-negative breast cancer. 


From this in vitro research, it is only a matter of time before a well-managed, clinical trial will emerge. Despite contemporary positive research findings, you will not find a retraction (or apology) by Sloan Kettering, and sadly, most cancer information sites still claim that Laetrile is useless as a cancer treatment and dangerously toxic. 

The “Dangers” of Raw Almonds

In 2007, the FDA claimed that raw almonds had been linked to two salmonella outbreaks in five years, leading to concerns about their safety. Suddenly, almonds were considered "dangerous." Typically, salmonella and E. coli contamination in our food results from unhygienic processing conditions. However, for bitter almonds, the required pasteurization process neutralizes the amygdalin compound, which seemed to align with the FDA’s agenda.

California almonds labeled as "raw" must undergo steam-pasteurization or chemical treatment with propylene oxide which destroys their amygdalin content.

However, this requirement does not extend to imported almonds or those sold directly from the grower to the consumer in small quantities. 

Amygdalin Availability

If any hospital in the U.S. decides to use Laetrile, they risk losing grants from the government as well as funding from Medicaid and other government-originated hospital insurance. Since most hospital revenues come from patient insurance, no hospital in the U.S. is willing to take the risk of using any banned substances, including amygdalin and Laetrile.

If a physician wishes to prescribe an amygdalin substance derived from apricot pits, they must have their patient complete a form, which is then submitted to the FDA. However, doctors generally prefer not to involve themselves in this process and would rather avoid being listed by the FDA. Individuals who sell Laetrile or amygdalin substances are prohibited from making any health claims for them in their place of business. 

In addition, many health food stores have been raided in the past and forced to surrender their supplies of amygdalin tablets because the products were displayed near books that made health claims for them. According to the FDA, this proximity constitutes "labeling," which is illegal and can lead to prosecution.

Internet Laws Are Different

However, the rules are different on the internet. Internet laws differ from U.S. commercial laws. A quick internet search will reveal both amygdalin tablets and injectable solution products for sale. Therefore, for the time being, it seems that the public can still purchase, use, and have amygdalin without breaking the law.

Both raw, bitter, organic almonds and organic apricot kernels are still available for purchase online. However, when considering factors such as availability, cost, and effectiveness, bitter apricot kernels emerge as an ideal option for incorporating amygdalin into one's diet.

Bitter Apricot Kernels

For those unfamiliar with bitter apricot kernels, here's a brief description: within the apricot fruit lies a hard shell. Breaking open this shell reveals a small seed or kernel resembling an almond, albeit softer and with a slightly bitter taste. It's important to note that both the apricot kernels and almonds must be sold as bitter to ensure a high amygdalin content.

While organic, raw, bitter almonds are less common and often sourced from Europe or Turkey, commercially grown almonds sold in the U.S. are typically of the "sweet" variety. Bitter almonds contain a high amygdalin content and are more potent compared to apricot kernels. Organic, bitter apricot kernels can be purchased inexpensively in bulk.


The recommended dosage of any food containing amygdalin is individualized and depends on several factors such as the user's weight, age, and health. Specific dosages should be guided by a health-care professional. Bear in mind, it is unwise to combine bitter almonds with apricot kernels. Generally, bitter apricot kernels are usually recommended over bitter almonds. Also, it is prudent to start with less and slowly build up tolerance.

Clinics in Mexico

Some cancer patients who visit clinics in Mexico may have been prescribed amygdalin tablets extracted from apricot kernels. These come as 100 mg and 500 mg tablets, in 100-count containers. Additionally, some patients are also prescribed the IV/IM 3-gram injectable amygdalin solution form. Each box contains 10 vials with 3000 mg of amygdalin extract dissolved in 10 cc of sterile water in each vial. As always, individual needs vary, and physicians may use slightly different dosages and protocols.

Laetrile treatment at Hope4Cancer Treatment Centers 

Dr. Antonio Jimenez of Hope4Cancer Treatment Centers has used Laetrile and amygdalin since 1988. Dr. Jimenez says, “Clinical dosages vary, depending on the method. If you are eating bitter apricot kernels for the first time, start with one, then wait a few hours before consuming more. Everyone is different, and it may take some time for your body to adjust to the desired level of B17.  

The ideal oral pill dosage is a 500mg tablet or capsule a half hour before each meal and another 500 mg before bedtime, for a daily total of 2,000 mg. More or less than that will not be as effective.” (See this video.)

Alternatively, Dr. Jimenez’ clinics give 3-9 grams of Laetrile a day intravenously, usually administered 6-7 days a week, depending on the individual case. The Laetrile is diluted in a saline solution and dripped into the patient during a 30-minute time frame.

And lastly, Laetrile also can be given through intramuscular injections, but Dr. Jimenez notes that it is painful, especially day after day, and there is a danger of noncompliance.

For many of today’s therapeutic uses, the primary source of amygdalin is apricot seeds. For active cancer patients, Dr. Jimenez recommends anywhere between 20 and 40 kernels a day. The variance depends on the patient’s history, where the cancer is located, how advanced it is, and other factors. As a preventive measure for everybody or for patients in remission, he recommends 14-16 kernels a day. 

Although all the methods of receiving Laetrile or amygdalin have their value, intravenously is considered the best, most-preferred method, followed by pills and then by ingesting apricot seeds. Also, for better results, Dr. Jimenez combines the Laetrile in his clinics with Vitamin C, and several minerals, particularly zinc and selenium.

Other Considerations

Today, some manufacturers are incorrectly labeling their iso-amygdalin products as amygdalin. It's crucial to understand that even meticulously extracted amygdalin is highly unstable when stored or shipped in solution. Minor fluctuations in temperature or pH can cause many molecules to adopt the same unnatural configuration as those obtained through poor extraction methods, leading to a reduction in therapeutic effectiveness. Amygdalin solutions of indefinite age also pose unpredictable quality and should be avoided.

According to Dr. Krebs, Jr., all injectable Laetrile amygdalin must undergo lyophilization (freeze-drying). Any product not subjected to freeze-drying cannot be considered Laetrile amygdalin. 

It's prudent to primarily rely on apricot kernels as a source of amygdalin, especially if there are doubts about the quality of extracted amygdalin products.

Laboratory Monitoring

For individuals seeking to determine the precise daily consumption of apricot kernels or amygdalin tablets, they can request a thiocyanate blood test (serum thiocyanate) from their physician. 

Historically, serum thiocyanate tests were utilized to evaluate the effectiveness of smoking cessation programs, although this method is now being replaced by direct measurement of nicotine and cotinine levels in serum and urine. 

Nowadays, thiocyanate tests are primarily used to monitor sodium nitroprusside therapy and its potential toxicity.

For most purposes, the thiocyanate test serves as an excellent means to monitor amygdalin therapy. 

However, it's important to note that cigarette smoking can elevate serum thiocyanate levels, which may interfere with monitoring amygdalin dosage. Therefore, the physician should conduct a baseline serum thiocyanate test before the patient begins amygdalin therapy and repeat the test after two weeks of treatment. 

Many physicians prefer to conduct periodic testing to ensure therapeutic and safe blood levels are maintained.

Experts believe that to determine a therapeutic amygdalin level, a serum thiocyanate level should be a minimum of 15 mg per liter (or 1.5 mg per deciliter). However, there is still some dispute as to the most optimum range. Dr. Krebs Jr. held that the thiocyanate level should be maintained between 15 mg/liter and 25 mg/liter (1.5-2.5 mg/deciliter). 

Most doctors agree that serum thiocyanate does not reflect toxicity until the blood levels reach about 50 mg/liter (5.0/deciliter), though some laboratories still report toxic levels are above 20 mg/liter. However, some individuals will not experience any side effects until the levels reach 100 mg/liter (10.0/deciliter).

Treatment Side Effects

Side effects of too-high thiocyanate levels include rapid heartbeat, dizziness, muscle weakness, nausea, and possibly shortness of breath. If any of these symptoms occur, all sources of amygdalin (including fruit seeds) should be stopped immediately, and a physician should be contacted for further instructions. Usually, symptoms will diminish or completely disappear within 24 hours of amygdalin cessation. Drinking lots of water can help reduce symptoms.  Most physicians will remove their patients from the tablets or kernels for a few days and then reintroduce the amygdalin at a lower dosage.

Laetrile Clinics 

The Camelot Cancer Care Clinic in Tulsa, Oklahoma was shut down by the FDA on April 24, 2013. They were the last Laetrile Clinic in the US.  

Even though Laetrile has been banned in the U.S, it is still administered legally in several clinics in Mexico, Germany, and parts of Asia, usually intravenously as an important anticancer protocol.

However, apricot kernels and apricot-based pills can still be purchased in the U.S. from the internet and taken as a nutritional supplement. 

Concluding Thoughts

Amygdalin-containing plants have been nature’s answer to cancer since the beginning of time. Consuming foods and products containing amygdalin will continue to increase worldwide simply because it is an effective, inexpensive anti-cancerous substance with few side effects when properly used. 

Someday, amygdalin extracts will be FDA approved, but for now, apricot kernels, extracts, and injectable sources are still available. 

Despite the biased research of the 80s, positive amygdalin research reports continue to emerge, and hopefully in the future we will see clinical Laetrile amygdalin trials to be conducted in an objective and unbiased way. 


1. Krebs E.T, Jr. The Nitrilosides (Vitamin B-17) - Their Nature, Occurence and Metabolic Significance (Antineoplastic Vitamin B-17). Reprinted from the Journal of Applied Nutrition, Volume 22, Numbers 3 and 4, 1970. According to Dr. Krebs, Jr., zinc is an important transportation mineral for laetrile in the body. He found that laetrile would be unable to reach the cells if the patient’s levels of zinc were deficient. He also found that magnesium, selenium, and vitamin C all played an important part in maintaining the body's defense mechanisms.

2. Chevallier A . The Encyclopedia of Medicinal Plants. New York, NY: DK Publishing; 1996:254-255.

3. Li Shizhen (2003). Luo, Xiwen, ed. Compendium of Materia Medica: Bencao Gangmu. Beijing: Foreign Languages

  Press. ISBN 7119032607.

4. Chen JK, Chen TT. Chinese Medical Herbology and Pharmacology. California: Art of Medicine Press; 2004.

5. Moss RW (2005) Patient perspectives: Tijuana cancer clinics in the post-NAFTA era. Integr Cancer Ther 4: 65–86.

6. Newmark J, Brady RO, Grimley PM, Gal AE, Waller SG, Thistlethwaite JR. Amygdalin (Laetrile) and prunasin beta-glucosidases: distribution in germ-free rat and human tumor tissue Proc Natl Acad Sci USA 1981; 78: 6513-6516.

7. Committee for Freedom of Choice in Cancer Therapy, Inc. Anatomy of a Cover-up: Successful Sloan-Kettering Amygdalin (Laetrile) Animal Studies. 1975. This may be accessed from:

8. C.G. Moertel et al, A Clinical Trial of Amygdalin (Laetrile) in the Treatment of Human Cancer, New England Journal of Medicine 306(4):201-6 (1982).

9. M.L. Culbert, correspondence, New England Journal of Medicine 307(2):119 (1982).

10. Michael L.Culbert, D.Sc., Apricot Power: Laetrile as the Marine Corps of the "Alternative" Revolution, Townsend Letter for Doctors (June 1995).

11. Krebs, ET. Jr. The Extraction, Identification and Packaging of Therapeutically Effective Amygdalin, Extracted from a compendium of papers written by Dr. E. T. Krebs, Jr. co-discoverer and developer of Laetrile-amygdalin, for the John Beard Memorial Foundation, 1979. For anyone considering laetrile treatment, or wanting more information on this subject, Ernst Krebs Jr’s paper entitled “The Extraction, Identification and Packaging of Therapeutically Effective Amygdalin” is a must-read. According to Dr. Krebs, “Freeze drying (lyophilizing) is the only presently available method of preserving the natural laevo-amygdalin to be used parenterally for an indefinite period.” That “any vial or ampules containing an aqueous solution labelled amygdalin has by its very nature been mislabeled and should bear the label iso-amygdalin from which its lessened therapeutic efficacy could be deduced. Once in solution, the lyophilized amygdalin will reassume the unstable characteristics of the amygdalin molecule and should therefore be injected as shortly after being put in solution as possible.”

12.  Laetrile Flunks, Time; May 11th, 1981.

13. Park HJ, Yoon SH, Han LS, Zheng LT, Jung KH, et al. (2005) Amygdalin inhibits genes related to cell cycle in SNU-C4 human colon cancer cells. World J Gastroenterol 11: 5156–5161.

14. Chang HK, Shin MS, Yang HY, Lee JW, Kim YS, et al. (2006) Amygdalin induces apoptosis through regulation of Bax and Bcl-2 expressions in human DU145 and LNCaP prostate cancer cells. Biol Pharm Bull 29: 1597–1602.

15.  Zhou C,Qian L, Ma, Yu X, Zhang Y, Qu W; Enhancement of amygdalin activated with β-d-glucosidase on HepG2 cells proliferation and apoptosis Carbohydrate PolymersVolume 90, Issue 1, 1 September 2012, Pages 516–523.

16. Chen Y, Ma J, Wang F, Hu J, Cui A, et al. (2013) Amygdalin induces apoptosis in human cervical cancer cell line HeLa cells. Immunopharmacol Immunotoxicol 35: 43–51.

17. Makarević J, Rutz J, Juengel E, Kaulfuss S, Reiter M, Tsaur I, Bartsch G, Haferkamp A, Blaheta RA Amygdalin blocks bladder cancer cell growth in vitro by diminishing cyclin A and cdk2.PLoS One. 2014; 9(8):e105590. Epub 2014 Aug 19.

18. Qian L, Xie B, Wang Y, Qian J. Amygdalin-mediated inhibition of non-small cell lung cancer cell invasion in vitro International Journal of Clinical and Experimental Pathology. 2015 May 1; 8(5): 5363-5370

19. Lee HM, Moon A.  Amygdalin Regulates Apoptosis and Adhesion in Hs578T Triple-Negative Breast Cancer Cells. Biomolecules & Therapeutics. 2016 Jan 1; 24(1): 62-66.

21. Sodium nitroprusside is a potent hypotensive agent. It is used in the treatment of malignant hypertension and as an adjunct in the control of blood pressure in surgery.


bottom of page