The Truth about ´Vitamin´ B-17

Separating B-17 Myth From Reality

Amygdalin or laetrile? B-17 as a cancer ´cure´ is one of the most controversial subjects in ´Alternative cancer medicine´. Is there research to support it as an alternative cancer treatment? Is there research to support it as a complementary therapy? Is there research to support B-17 as a cure for cancer? Here we bring you one of the most comprehensive and accurate reviews on the Internet today (Written by Editor, Chris Woollams, M.A. Oxon, Biochemistry).

The controversy was re-opened in October 2014 when researchers (Makarevic et al; PLOSone) showed that natural B-17 (amygdalin) dose-dependently reduced growth and proliferation of cancer cells in vitro (See Cancer Watch – Click Here).

Controversy was furthered in May 2016, when the Food Standards Authority (FSA) in the UK talked about banning the sale of Apricot Kernels. So, a Government that puts a proven class A carcinogen (fluoride) in our water supplies is going to ban a food they don´t even correctly understand – they say, like many ignorants, that 30 of them ´contain cyanide´. Do they understand that for years people have eaten foods like marzipan in cakes. It was made from Apricot Kernels. UK nurses were even told to eat an apricot, then break the nut and eat the pip for health reasons, although I am going back 65 years to when my mother was a nurse.

What you are about to read is the Truth, the whole truth and not the rubbish the skeptics, people with agendas and propaganda-pushers, and generally ill-informed people would have you believe.

B-17: Laetrile is not the same as Amygdalin

Firstly, let´s get one thing straight: Beware the articles that talk of eating pips and seeds and call the active ingredient Laetrile. The writers are making a simple, but fundamental error. How many more will they make?

It is important to differentiate the use of natural amygdalin from Apricot Kernels, and Laetrile, which is a concentrated, synthetic drug.

But, when it comes to B-17, confusion exists everywhere and absolute rubbish is often talked, even from supposedly ´top´ websites.

B-17: Basic facts

A typically ignorant exchange happened on February 14th 2006, when the UK´s Daily Mail ran a headline ´Cancer Cures or Quackery?´ under which six alternative practitioners recommended ´alternative´ cancer cures (their words not mine) to a reporter posing as a cancer patient. To quote, ´One therapy was ´B-17 metabolic therapy or laetrile´ (sic).

Two UK cancer ´experts´, Professors Ernst and Baum, joined in the fray commenting that there was ´no research to support B-17´, and that B-17 was used ´by a few unscrupulous practitioners across the border in Mexico´.

1. People who have looked into this subject in depth (like Ralph Moss and Phillip Day) will tell you that there are at least five studies (three on animals, two with humans) that show some effect on cancer with B-17. But the fact is that the evidence base is poor. Very poor. There is no accepted placebo-controlled, randomised clinical trial data whatsoever with humans, although Moss (who was a science writer working in the press office at Memorial Sloan Kettering when they did conduct serious research), will tell you that the results were good  (B-17 was shown to stop help prevent cancer, stop metastases and clinical trials were recommended), but he watched as people suppressed them (Click Link for You Tube trailer)

2. Treating people with Metabolic Therapy is not the same as giving them B-17. The world famous Oasis of Hope clinic in Mexico uses a variety of therapies including radiotherapy and chemotherapy. And it does use synthetic ´vitamin´ B-17 as a part of a package called Metabolic Therapy, which may also include pancreatic enzymes, ozone therapy, Intravenous Vitamin C and more. Does it work, and if so which bit? Although there is clearly a lot of anecdotal evidence, and I have talked at length with Contreras, himself, no overall report or rigorous data seems to exist for Metabolic Therapy either, sorry.

3. The owners of the Oasis of Hope have not been chased out of America, nor are they ´unscrupulous´. Dr Francisco Contreras M.D., the son of the founder Dr Ernesto Contreras, and his hospital are in Mexico … because they are Mexican. The Oasis of Hope advertises in America perfectly legally, and Americans travel to the clinic in Mexico, just as they might go to one in Chicago.

By April 14th the UK Food Standards Agency was getting in on the act. UK newspapers published warnings issued by the FSA thus: ´Cancer patients should be aware that Apricot Kernels – a suggested cure for the disease – can kill them´. Apparently, ´Reports from overseas say eating 20-30 could result in very serious health effects´.
Note: None of the articles specified the origin and the detail of these ´overseas reports´. There was absolutely no evidence for these claims.

The FSA suggested that 1-2 pips per day was a safe intake. One article went on to add, ´Bitter apricot pips are thought to contain high levels of B-17, known as laetrile (sic) – described as an immune system booster and even as a cancer treatment´.

4. Bitter apricot pips contain amygdalin, not laetrile. Few people seem to grasp the difference but it is important:

(i) Apricot Kernels can contain up to 3 per cent of Amygdalin which is the natural form of B-17. If you chew a pip it tastes rather like old-fashioned marzipan. Eating apricot kernels does not require any medical approvals – nor should it any more than eating oranges or beetroot.

(ii) Laetrile is something quite different – it is a synthetically prepared form of B-17 and is thus a drug and is subject to drug approval. Since there are no definitive phase III clinical trials on laetrile, quite correctly it has not received FDA approval. Full stop.

(iii) B-17 is not a vitamin. Krebs (see below) described it as a vitamin, but there is little evidence of any vitamin properties.

(iv) Contreras, the world´s expert on B-17, states unequivocally that he knows of no one who has ever died from eating apricot pips. He does not treat people with apricot pips and it matters not to him whether they help or hinder. He is providing an unbiased expert opinion.

(v) Apricot pips alone are not a cure for cancer. I know of no one who says they are. In the world. They might well perform a role in an anti-cancer complementary treatment package. Eating a few each day may also have some preventative powers.

(vi) I also know of no one who has been treated by laetrile alone and has cured their cancer – I cannot even provide an anecdote.

5. The problem was that B-17 (synthetic laetrile, not amygdalin) became the focus of a mighty squabble between orthodox medicine and alternative medicine.  ´Conspiracy theories´ abound in the world of alternative cancer treatments and views become entrenched. And this creates the mythology and the errors. Certain people close to the Pharmaceutical Industry then involved amygdalin, incorrectly, in the laetrile argument.


Apricot Kernals and Integrative Cancer Treatment

The fact is that I personally know of a very large number of people who take apricot kernels (6 with their breakfast), and hundreds more who have used up to 50 apricot kernels a day, within a no glucose, no cows´ dairy, and an alkalising diet, as part of their Complementary and Integrative Treatment ´package´ (along with exercise etc.) when they had cancer. And the package delivered for them. Geoffrey Boycott, the former English Cricketer, would be a good example, as would Sue Olifent, who will tell her story on ´Health Academy Live´ .  Sue had liver and pancreatic cancer and the doctors sent her home because there was nothing they could do for her. 6 months later and the tumours are scars. She has set up a Support group, Active Cancer Support (Click Here), to help people find out more.

Now, there are You Tube videos often along the lines of ´I beat cancer with vitamin B 17´. By all means watch them – e.g Sandi Rog. But you will find they almost all confuse what I have been saying above. That doesn´t detract from their belief that B-17 helped them beat cancer, of course.

B-17: The basics

6. You can crack open an apricot nut shell today in the UK – but it is against the law to treat someone with laetrile.

        a) Apricot Kernels, seeds, pips, whatever you want to call them, contain amygdalin and this is a nitriloside. A large number of bioactive compounds are provided by nature (e.g. carotenoids, phenols, anthocyanins, vitamin D, curcumin, resveratrol etc.) which can protect and correct illness; nitrilosides are one. Salvestrols (developed by Professors Potter and Burke) act similarly. Interestingly, Salvestrols (click link)  and amygdalin should not be taken simultaneously as they can contra-indicate.
        b) Laetrile (the synthetic form of B-17) can be obtained in tablet form (500 mg units) for home consumption, but is more usually administered intravenously.
        c) Laetrile prescription is illegal in the UK. No practitioner in the UK has been allowed to prescribe or use synthetic B-17 since June 2004. It has been banned since 1963 in the USA by the FDA; however, some Naturopathic practitioners in the USA seem prepared to sell laetrile to patients; and you can even buy it on Amazon!
 I know of no-one who claims that either Apricot Kernels, or synthetic
B-17 (laetrile) is a cancer ´cure´, on its own.

d) A cure for cancer? The word ´cure´, in my experience, is only ever used by the press, or by dubious websites and ´experts´ who don´t really understand cancer. These may be staunch advocates of alternative therapies, or Skeptic twaddle sites. Neither is helpful to the cancer patient.


Cancer is a multi-step process. There may be as many as 20 steps (according to John Boik of the MD Anderson Cancer Center in Texas). In my book, ´The Rainbow Diet – and how it can help you beat cancer´,

I have assigned bioactive foods and natural compounds to each of the steps, but only where there is scientific research that they have an anti-cancer step activity. I know of no single natural compound that is active against all 20 steps.

No drug cures all cancers, all of the time. There is no drug known to man that kills cancer stem cells at the heart of cancers. Why expect it, or claim it for a vitamin, or B-17?

e) All drugs have side-effects. Those of Tamoxifen are well documented. The lack of proper research on synthetic B-17 (laetrile) has meant no safety measurements really exist. Death claims are twaddle.

Eating too many Apricot Kernels, or too much beetroot, or too much Asparagus, or drinking too much water will cause negative effects in the body. Amygdalin does cause problems if the liver is impaired; and according to the US Nutrition Almanac you should never eat more than 6 in a 90 minute period, and the maximum in 24 hours is 35. Some people I know use 50 a day as part of their anti-cancer diet package. See below for liver concerns.

So from this point on, when reading this article, at least put synthetic B-17 (laetrile) and Apricot Kernels (amygdalin) into a proper and separate perspective.

For more up-to-date information on Laetrile and Metabolic Therapy, you could contact the oracle, Dr Contreras at the Oasis of Hope.

For more on the role of Nitrilosides in treating cases of Sickle Cell Anaemia (Click Here).

Natural B-17: A group of compounds

Every area of the world supporting vegetation has such plants

B-17, or amygdalin, is a naturally occurring compound. In fact it is slightly wrong to think of it as a single entity like, say, vitamin C. There is a group of approximately 14 compounds that are water-soluble and found naturally in over 1,200 species of plant in the world. Every area of the world supporting vegetation has such plants.

The active ingredients are often described as nitrilosides or beta-cyanogenetic glucosides and there are at least 800 foods common in worldwide diets that are nitrilosidic.

Nitrilosidic foods include:

  • alfalfa sprouts, bamboo shoots, mung bean sprouts
  • barley, buckwheat, maize, millet, sorghum
  • blackberries, currants, cassava, cranberries, gooseberries, chokeberries
  • loganberries, quince, raspberries, strawberries, yams
  • brown rice, fava beans, lentils and many pulses like kidney beans, lima beans and field beans
  • flaxseed/linseed
  • pecans, macadamia nuts, cashews, walnuts, almonds
  • watercress, sweet potato
  • the seeds/pips of lemons, limes, cherries, apples, apricots, prunes, plums and pears.

In fact, all the foods we don´t eat too much of these days!!

The consumption of barley, buckwheat and millet have given way to refined wheats, while pulses like lentils, which accounted for 30 per cent of our protein in 1900, now account for only 2 per cent.

Primitive tribes around the world still base their diets around B-17-rich foods. Cassava, papaya, yam, sweet potato in the tropics; unrefined rice in the Far East; seeds and nuts in the Himalayas; the salmon-berry eaten by Eskimos, or the arrowgrass of the arctic tundra feeding the caribou.

B-17: Its place in nature

This absence of cancer seemed to be due to the difference of nutrition

Nutritionist and scientists alike studied the various tribes. Sir Robert McCarrison in the 1920s and John Dark M.D.twenty years later failed to find a single case of cancer amongst the Hunzas, the tribes of West Pakistan. V Steffanson found the same with the Eskimos and wrote “Cancer: Disease of Civilisation” as a result. Dr. M Navarro of Santo Thomas, University of Manilla, noticed the same with the Philippine population who ate cassava, wild rice, wild beans, berries and fruits of all kinds. Dr. Albert Schweitzer noted the same in Gabon. ´This absence of cancer seemed to be due to the difference of nutrition in the natives compared to the Europeans. Their diet was centred around sorghum, cassava, millet and maize´.

Studies of the consumption of B-17 varied from Dark´s finding that the Hunzas consumed at least 150-250mgs per day, to Dean Burke, head of the cytochemistry department of the National Cancer Institute in the USA in the seventies writing that the Modoc Indians in North America consumed over 8,000 mgs per day! (Dean Burke actually gave amygdalin the name B-17).

We leave these foods aside at our peril. The World Health Organisation has, after all, confirmed that in their view a large percentage of all cancers could be prevented by simple changes in diet.

B-17 as a cancer treatment?

Amygdalin was first isolated in 1830 and used as an anti-cancer agent in Russia as early as 1845.

But it was reborn by the father/son team Ernst Krebs senior and junior by 1955 had who isolated a purified form of the active ingredient (calling it laetrile) and, with others in the late fifties to seventies, sought to explain its action.

B-17: A seek and destroy missile?

Cancer cells differ in a number of ways from normal cells. One major difference is the way in which they produce their energy. In a healthy cell fuel is prepared in the cytoplasm of the cell, and then moved into the mitochondria or power stations to generate energy in the presence of oxygen. But cancer cells have lost their mitochondrial action and only the preparation process remains. This is modified and demands large quantities of glucose which burn in the cytoplasm in the absence of oxygen. Cancer cells have a whole different energy production system and different set of helper chemicals (enzymes).

 B-17 is a seek and destroy missile

In a cancer cell, one of these enzymes, glucosidase, is present at 3000 times the level found in normal, healthy cells. Glucosidase has a unique action with B-17, breaking it down into hydrogen cyanide (which kills it) and benzaldehyde, (an analgesic).

However, in normal cells where glucosidase is virtually non-existent, a completely different enzyme, rhodenase which is involved in the normal oxygen burning process, actually renders the B-17 harmless, converting it to thiocyanate, a substance which helps the body regulate blood pressure, and vitamin B-12. So, the proponents argue, B-17 is a seek and destroy missile.

“I have read B-17 is dangerous – it contains cyanide”

As we explained above – the B-17 molecule, if broken a certain way, can produce cyanide. But the main enzyme that can do this is really only found in a cancer cell.

Also, frankly, it is rather a daft argument; rather like saying the glucose molecule contains carbon monoxide and that can kill you!

Skepti-twaddle about B-17 often refers to people dying of B-17 and cyanide but Contreras, who treats more people with B-17 than probably all other doctors in the world added together, knows of no cases.

Then there is the fact that ´containing cyanide´ could be claimed for many food groups (for example, isothiocyanates, or anthocyanins). These food groups actually play important roles in your health, including in cancer prevention.

Next, doctors regularly inject vitamin B-12 to enhance energy levels; you can buy vitamin B-12 on the high street. This common form is cyano-cobalmine. A layman might tell you this ´contains´ cyanide in the same way, too.

Vitamin B-12 is involved in over 300 enzymatic reactions in the healthy body, a deficiency is known to be linked to increased cancer risk. The more natural form of vitamin B-12 is methyl-cobalmine. If a compound containing cyanide is so bad, what is the medical profession doing it injecting it into lethargic pop stars and athletes?? If it contains cyanide and that is dangerous, why don´t doctors use the methyl version?

Nobody in their right mind would tell you not to consume B-12. So, steer clear of anyone who uses this palpably ignorant argument against B-17.

B-17: Why the controversy?

The use of synthetic B-17 is controversial because of conspiracy theories. It is a Skeptic versus Skeptic argument. The Skeptics against B-17 scream ´quackery´; the skeptics for B-17 scream ´cover up´:

The Federal Drug Administration (FDA) in the USA has not approved laetrile – the FDA state, correctly, that laetrile (not amygdalin or B-17) is a synthetic therapy and, as such, needs approval like any drug. There are no randomised, controlled phase III clinical trials on laetrile so it is definitely not going to be approved. Yet people around the world do prescribe and use it. QED, they must be quacks. That´s the official view. It was actually banned in 1963, although the FDA reported that it had harmed nobody and they also said it didn´t work!

But a core question is why has the same US Government Health Authority, the FDA, moved to ban the interstate shipments of apricot kernels and the planting of bitter almond trees? Trying to control a natural bioactive compound that logically might have some preventative benefits fuels the conspiracy theories! I noticed that my mother´s Asda “iced log” (a cake) contained 11 per cent apricot kernel paste! Presumably this cannot be moved between California and Nevada!

One skeptic argument runs ´If eating apricot pips could cure cancer, drug companies and major cancer charities would go out of business immediately´. Actually, these businesses need not panic.

Let us look at the ´research´ issue …

B-17: Any specific research?

Three quarters of 80 cancer test patients had seen their cancer tumours go or reduce in size

Well yes, actually there has been some research – but not much. Ralph Moss and Phillip Day seem to be the experts here and they both record that there have been three animal studies and two human studies.

Following the Krebs´ work in 1955 a Senate Committee (often accused of being biased presumably because of drug industry connections) seemed unimpressed by evidence presented that three quarters of 80 cancer test patients had seen their cancer tumours go or reduce in size.

There was a stab at a clinical trial in the USA and this officially reported no effect with B-17. Moss was the Press officer in the team and showed his disgust at the public hearing, implying that the team had actually found a positive response and the powers that be were mis-representing the findings. He was fired.

However, talk to the experts that use B-17 and they will tell you that researching B-17 in a clinical trial is not the issue anyway. None doubts its efficacy, but several felt it was not as potent as other ingredients such as Intravenous, high dose vitamin C. ´B-17 only ´helps´ and is not a ´cure´ per se´, seems to be the general view. The issue, they argue, is to research the whole ´metabolic therapy´ package. The authorities have never done this. The people who use and advocate it simply cannot afford to conduct a full scale clinical trial. Impasse.

Why might it be more important to research the whole package? Cancers are clever and often form protective protein coats around the tumour to ward off the immune system. Various cancer clinics have thus developed their metabolic therapy packages to counter defences like these (metabolic therapy packages can contain bromelain, from pineapple and papain, from papaya, because they supposedly break down the protein coat). Other unique factors occur with cancer cells, so the metabolic therapy package may contain vitamins A, E and B complex, plus high dose intravenous vitamin C, high dose minerals, and pancreatic enzymes, each targeting a specific issue.

The difficulty then becomes “which bit worked?”

Having personally talked to leading B-17 practitioners in the USA and Europe, a few actually answer, ´who cares!´? Actually, I do.

Frankly, this is quite important but the answers are unsatisfactory if you are a cancer patient. On different pages we have reviewed the use of intravenous vitamin C megadoses and pancreatic enzyme treatment as used by Dr Gonzalez in his clinic in New York. They do seem to have, albeit limited, effects on their own, so I suppose it is possible that using all of them could have a greater effect. But, be clear, there is NO FORMAL RESEARCH on the metabolic therapy package and in reality it doesn´t even exist as different clinics use different concoctions.

Metabolic therapy packages could be working in several ways,
but there´s no research

Finally, laetrile has shown effectiveness against cancer cells in vitro, and in rats and mice. Interestingly, even the National Cancer Institute in America (which is negative about laetrile´s abilities), reports that by the late seventies over 70,000 cancer patients had been treated with laetrile and that there are copious individual case histories on its effectiveness. (Notwithstanding this, modern medicine demands a phase III clinical trial and there is none).

Krebs recommended eating ten apricot seeds per day for life (the seeds or kernels of apricots have the highest levels of B-17; up to 3 per cent); cancer treatments use four to six 500mg tablets of laetrile per day or intravenous injections.

B-17: Can it kill me?

While there may not actually have been deaths from synthetic B-17 use, there is definitely an issue with overdosing.  If you take excess B-17 beware; cyanide by-products have been known to build up in the liver of cancer patients.Each of us has different capacities to deal with such by-products but a cancer patient has an already impaired liver. A healthy liver has an enzyme, glucorinide that can detox the by-products, but in a cancer patient, this enzyme may be depleted. So, cyanide poisoning can result if excess is consumed. 1gm is the maximum recommended to be taken at any one time.

With the natural form of B-17, the US Nutrition Almanac recommends a maximum of 35 seeds per day; no more than five kernels at any one time in a 90 minute period. And they conclude that all cancer treatments using B-17 (synthetic, natural, or apricot kernels) should be properly supervised. Certainly, I have seen several prostate cancer patients who looked decidedly yellow all because they were trying to consume 50 kernels for breakfast!

B-17: Subjectivity and objectivity

As readers know, I travel the world giving speeches on cancer. I have interviewed a number of the world´s experts who use B-17 and metabolic therapy, including ´The Mexicans´, although maybe I met the wrong ones as these certainly were not unscrupulous!

I will say that on a totally subjective note:

a) I have seen many people, especially men with prostate cancer, who claim Apricot Kernels are the single reason their PSA scores have reduced.
b) Contreras himself claims that metabolic therapy can ´have a significant effect´ on some cancers – though not all. He is quite clear that there is no effect with Brain Tumours, Liver Cancer or Sarcomas.
I have seen overdosing with my own eyes. Be very, very careful.
c) As I said above, I have seen overdosing with my own eyes. Both men in their 60´s, both prostate cancer sufferers and both trying to eat 50 Apricot Kernels for breakfast. Both had gone a sort of yellowish-grey. Be very, very careful.

To repeat:

* Never take more than 5 in a 90 minute period.
* Never take more than 35 per day.
* Please tell your doctor, and have someone monitor your liver health.

B-17: Does it work in cancer treatment?

Having read the original research on synthetic B-17 laetrile treatments and spoken to doctors and patients first hand, I find the ´evidence´ both for and against laetrile almost non-existent. I am neither an advocate, nor a critic. I just don´t know, even though I have tried to find out more.

The logic on B-17 seems reasonably sensible and certainly pharmaceutical companies are devoting significant resources to targeting exactly the same unique properties of a cancer cell. But, as I repeatedly say, I don´t think any single entity is a ´cure´ for cancer – and that goes for B-17 too. Could it play some or other role in the total package? Experts like Contreras are adamant it can. There are people of You Tube who swear it worked for them. I´m not at all as sure. Would I pin my hopes on it alone? No. But then many of the subjects were past the point of no return – orthodox medicine had failed them.

B-17 – even eating too many apricot kernels – can be dangerous
if your liver is impaired

With Apricot Kernels, and amygdalin, for me there is a different issue. I believe everybody should include nitriloside foods in their daily diet. I put five – six kernels with my home-made breakfast each morning, but then I eat copious amounts of food off the B-17 list above anyway. Personally, I believe there is a good prevention argument, and eating half a dozen ´apricot pips´ a day is hardly a dangerous medical issue.

So, B-17 “Cancer cure or quackery?” The Bottom Line

There is a good argument for including apricot kernels in your anti-cancer programme as a preventative bioactive compound.

However, no one has ever approached me and told me that eating 50 apricot kernels a day alone ´cured´ their cancer.  In fourteen years not one person has so much as come up to me on my worldwide travels with even an anecdote.

However, many, many people I know have used them (35-50) as part of their anti-cancer treatment package (most often diet-based) and the package worked. Also there are You Tubes of people who beat cancer this way.