Vitamin B17 is the name often used to describe an FDA-discredited anticancer drug that is made from the seeds of apricots, peaches and almonds. Due to lack of evidence regarding its effectiveness as an alternative treatment for cancer, it's important to know about the dangerous and serious side effects that could result from taking vitamin B17.
What Is B17?
Your body does not need B17, so it cannot be classified as a vitamin. Vitamin B17 is an inaccurate name for a compound called laetrile. Laetrile is a purified derivative of a substance called amygdalin, and the two names are often used interchangeably. Amygdalin is a natural plant compound that is contained in many foods, especially raw nuts.
Where Does Amygdalin Come From?
Amygdalin is found in over 1,000 species of plants, particularly among the Rosaceae family. Many of these plants have been used for traditional food medicines for centuries in numerous cultures, according to the Marion Institute. The most common B17 foods that contain amygdalin are:
- Seeds of fruits or kernels: apricot, peach, cherry, apple, prune, nectarine, plum, pear
- Nuts: macadamia, bitter almond, walnuts
- Beans: Burma, broad beans, sprouted lentils, mung beans, lima, scarlet runner, Rangoon
- Berries: Nearly all wild berries,for example, blackberry, cranberry, elderberry, raspberry, strawberry, chokeberry, Christmas berry
- Grasses: wheat grass, acacia, white Dover, sprouted alfalfa, milkweed, Sudan
- Seeds: flax, sesame, chia
Plants containing amygdalin depend on a compound they produce for their defense. Cyanogenic glycosides in the plants deter grazers and herbivores. Additionally, amygdalin controls germination, bud formation and possibly acts as an antioxidant.
What Is the Laetrile Health Claim?
Laetrile has been used as an anticancer agent as early as 1845 in Russia, and its use began in the United States during the 1920s. Laetrile continued to grow in popularity as an anticancer treatment, and by 1978, more than 70,000 Americans were reported to have been treated with it.
Today, the sale of laetrile is banned in the U.K. and Europe, as well as in the USA by the Food and Drug Administration, due to its potentially adverse side effects. However, laetrile continues to be manufactured and administered as an anticancer therapy primarily in Mexico, but also in some clinics in the U.S.
How Is Laetrile — B17 Made?
Although the names laetrile, vitamin B17 and amygdalin are often used interchangeably, they are actually not the same product. The chemical composition of the synthetic derivative of amygdalin differs from the laetrile/amygdalin produced in Mexico, which is made from apricot pits. The cyanide component, called mandelonitrile, is contained in both products.
The natural form of laetrile is made in Mexico from extraction of ground apricot fruit kernels. The process involves defatting the ground kernels using a solvent. The hydrogen cyanide compound from laetrile forms the basis of the alternative anticancer treatment plan. The belief is that cyanide increases the acid content of tumors and leads to their destruction and also inhibits cells from reproducing.
How Is Laetrile Administered?
Laetrile is often prescribed in combination with special diets, high doses of vitamins and pancreatic enzymes. Laetrile is available in a tablet, by intravenous or intramuscular injection, or as a lotion for the skin or rectum. Marion Institute says it is estimated that 33 apricot kernels are needed for each 500-milligram tablet, which contains 30 milligrams of cyanide. The oral form is estimated to be 40 times more potent than the injectable form.
The Dangers of B17
The primary concern with B17 is from the formation of cyanide in your body. Upon ingestion, amygdalin generates toxic hydrogen cyanide in the stomach. Hydrogen cyanide dissolves to form the cyanide anion. Cyanide is a rapidly acting and deadly poisonous compound that can prevent cells from using oxygen and eventually kill them, according to a 2017 review by Case Reports in Emergency Medicine.
Symptoms of Cyanide Poisoning
Since laetrile produces cyanide, a neurotoxin, the side effects of laetrile mirror those of cyanide. Mild to severe cases of poisoning can cause symptoms, including:
- Nausea and vomiting
- Weakness and dizziness
- Mental confusion
- Abdominal pain
- Liver damage
- Low blood pressure
- Droopy upper eyelid
- Cyanosis — a bluish cast to the skin and mucous membranes
- Irregular heartbeat
- Cardiac arrest
- Circulatory and respiratory failure
Some of these symptoms can be exacerbated if laetrile is taken at the same time as raw almonds or crushed fruit pits, or fruits or vegetables containing beta-glucosidase — celery, peaches, bean sprouts or carrots — or by taking high amounts of vitamin C, according to "PDQ Cancer Information Summaries."
Is Laetrile Effective?
Much research has been done in laboratory and animal studies to test the effects of laetrile, but limited scientific evidence from controlled trials suggests that laetrile is an effective treatment for cancer or any other illness. There are conflicting reports due to some positive feedback from in-vitro and animal studies. However, human clinical trials have not found that laetrile has similar effective outcomes and considers the risk–benefit balance of laetrile or amygdalin as a treatment for cancer to be dangerous due to side effects and lack of survival rate.
A systematic review, updated to 2018, assessed anti‐cancer effects and side effects of amygdalin and laetrile from evidence collected from previous studies. The conclusion, published in Cochrane Systematic Review, found no beneficial effects from laetrile, or preparations containing amygdalin, on the treatment of cancer. Researchers warned of risks from serious adverse effects from cyanide poisoning, especially after oral ingestion of the product. Furthermore, it was suggested there is no scientific or ethical justification for further clinical trials with amygdalin or laetrile as a therapeutic agent for cancer.
A study published in Biochemistry and Biophysics Reports in 2018 warns of the dangerous use of amygdalin as a therapeutic agent due to undefined, toxicity-causing dosage levels and unstandardized modes of administration. Since there is no government control over the way vitamin B17 is prepared, batches of amygdalin or laetrile can vary in purity and content and could be contaminated if bought from questionable sources.
A Word of Warning
It is understandable that you might be willing to try anything to treat or cure your cancer. Only you can decide whether to use conventional or alternative cancer therapy. Although many websites promote laetrile or B17 supplements as a cure, no reputable scientific cancer organization supports the claim that laetrile has an effect on treating cancer. The B17 side effects have been shown to be harmful to your health, even fatal, so consider the potential consequences before using any unproven treatments.
Read more: How to Purchase Vitamin B17
- PubChem: Amygdalin
- WebMD: Is Amygdalin a Safe Cancer Treatment?
- Marion Institute: Amygdalin and Laetrile – History and Current Usage
- NCBI: "PDQ Cancer Information Summaries": Laetrile/Amygdalin
- Cancer Research UK: Laetrile (Amygdalin or Vitamin B17)
- Cochrane Database of Systematic Reviews: Laetrile Treatment for Cancer
- Biochemistry and Biophysics Reports: Effects of the Gut Microbiota on Amygdalin and Its Use as an Anti-Cancer Therapy: Substantial Review on the Key Components Involved in Altering Dose Efficacy and Toxicity
- NIH: National Cancer Institute: Laetrile/Amygdalin (PDQ®)–Patient Version
- Case Reports in Emergency Medicine: Physician Beware: Severe Cyanide Toxicity From Amygdalin Tablets Ingestion
- Complementary and Alternative Methods for Cancer Management by the ACS