Amygdalin is known by several names. Laetrile, letril, and also vitamin B17 — these are all terms used for the same substance, though the last one is technically incorrect. There is no officially recognised vitamin B17, even though this name is widely used. Amygdalin is responsible for the bitter taste found in the seeds of cherries, plums, apricots, peaches, and sweet cherries. First identified in the 19th century, it gained popularity due to its alleged anticancer properties. But does vitamin B17 truly offer an alternative approach in oncology?
What Is Amygdalin?
Amygdalin is a glycoside — a naturally occurring compound found in plants. It is the substance responsible for the characteristic bitter flavour you notice when eating fruit close to the stone. The highest concentrations occur in bitter almond kernels, but significant amounts are also present in the seeds of quince, apricot, plum, cherry, and peach. Beyond stone fruits, amygdalin appears in legumes such as broad beans, kidney beans, chickpeas, and lentils. It is also found in berries like blackberries and chokeberries, as well as in flaxseeds, sesame seeds, bamboo shoots, and brown rice. Macadamia nuts and cashews are among the richest nut sources.
If you're interested in plant-derived compounds and their role in wellness, you may also want to explore our selection of herbal supplements that feature concentrated botanical extracts.
[note:Amygdalin is sometimes marketed as "vitamin B17," but it has never been officially classified as a vitamin by any major scientific or regulatory authority.]Amygdalin — Properties and Mechanism
In the human body, amygdalin undergoes a series of chemical reactions and ultimately breaks down into prussic acid (hydrogen cyanide), glucose, and benzaldehyde. Two of these breakdown products — hydrogen cyanide and benzaldehyde — can negatively affect the body in excessive amounts and may even lead to serious poisoning. This is an important safety consideration that should not be overlooked.
Proponents of alternative oncological approaches disagree with this assessment. According to their theory, amygdalin breaks down into these potentially harmful compounds only within cancer cells, leaving healthy cells unaffected. They suggest that an enzyme called beta-glucosidase enables hydrogen cyanide to penetrate diseased cells, allowing benzaldehyde to destroy them from within. Under this theory, vitamin B17 would not only target mutated cells but also help prevent metastasis by shortening the lifespan of affected cells. Supporters claim amygdalin could work both therapeutically and preventatively against cancer.
[warning:The anticancer claims surrounding amygdalin remain unproven by mainstream science. Never use amygdalin as a substitute for conventional cancer treatment. Always consult a qualified healthcare professional before considering any supplementation.]However, the scientific reality is more nuanced. Researchers have pointed out that cancer cells contain insufficient quantities of the necessary enzyme to absorb amygdalin in meaningful amounts. Only trace amounts may reach cancer cells — not enough to destroy them — while the remaining substance could potentially harm healthy tissue.
What Does the Research Say?
The scientific evidence on amygdalin and cancer is mixed and inconclusive. Some studies have observed slower growth of colon cancer cells in laboratory settings. Others have explored its potential role in supporting prostate cancer treatment, and one animal study on rats suggested a possible influence on breast tumour treatment. However, alongside these findings, numerous studies have shown absolutely no effect on cancer treatment, prevention, or progression.
Until further rigorous clinical research is conducted, it remains impossible to definitively determine whether amygdalin has any real impact on cancer cells. What is clear is that this compound has attracted significant scientific curiosity, and ongoing research may eventually provide more definitive answers. For those interested in antioxidant supplements with better-established evidence, there are many well-researched options available.
[tip:If you're interested in evidence-based compounds that support cellular health, consider well-researched antioxidants such as vitamin C, vitamin E, selenium, or coenzyme Q10.]Amygdalin — Dosage
There is no universally agreed-upon dosage for amygdalin, which reflects the ongoing scientific uncertainty surrounding this substance. For general preventive purposes, some practitioners suggest incorporating small amounts of ground fruit seeds into the diet. However, when it comes to cancer-related use, the situation is far more complex and should never be approached without medical supervision.
As an example, Dr. Contreras of the Oasis of Hope Hospital has proposed a phased approach: six 500 mg tablets daily for 21 days in phase one, four 500 mg tablets daily in phase two, and a continuation of phase two or a reduction to preventive amounts in phase three. Other researchers take a more conservative stance, recommending no more than one to two seeds per day strictly for general wellness purposes, while advising against therapeutic dosing altogether.
Supplemental forms of amygdalin, such as those available in capsule form, typically contain much lower doses (around 4 mg) and are designed for those who wish to include this compound as part of a broader supplement routine.
[products:medica-herbs-amigdalin-b17-4-mg-60-capsules, vitalers-amygdalin-vitamin-b17-4-mg-120-capsules]Amygdalin — Contraindications and Safety
Starting amygdalin supplementation should always be discussed with a doctor, especially in the context of a cancer diagnosis. Self-administering this substance can have serious consequences, particularly if it leads someone to abandon conventional oncological treatment in favour of alternative approaches.
Amygdalin is generally not recommended for individuals with cardiovascular conditions, as preparations containing this compound may lower blood pressure. It can also impair digestive function, potentially leading to indigestion, heartburn, abdominal pain, bloating, and nausea. In cases of malabsorption syndrome, amygdalin may further reduce the absorption of other valuable nutrients.
It is also important to note that amygdalin can interact with other medications. Taking it alongside ascorbic acid (vitamin C), for instance, may increase the risk of adverse effects. For this reason, any decision to supplement with amygdalin should be made in consultation with a healthcare professional who can assess potential interactions with existing medications and health conditions.
[warning:Excessive consumption of amygdalin can lead to cyanide poisoning. Symptoms include headache, dizziness, nausea, and in severe cases, convulsions. Never exceed recommended amounts and always seek medical advice.]Key Takeaway
Amygdalin, commonly referred to as vitamin B17, is a fascinating plant-derived compound with a long history of interest in alternative health circles. While some preliminary research hints at potential properties worth exploring, the scientific consensus does not currently support its use as a cancer treatment. If you choose to supplement with amygdalin, do so responsibly — at low doses, under medical supervision, and never as a replacement for proven medical therapies.
