Amygdalin, also known as B17, is a compound found naturally in the seeds and kernels of several fruits, most notably apricots. It is a cyanogenic glycoside, a molecule that releases hydrogen cyanide upon breakdown. This compound is often associated with the semi-synthetic derivative, Laetrile, historically promoted as a cancer treatment. The name “Vitamin B17” is a misnomer, as it is not recognized as a vitamin by nutritional science. Acquiring this substance requires understanding its different forms, complex regulatory status, and the safety concerns related to its toxicity.
Defining Amygdalin and Its Regulatory Status
Amygdalin, Laetrile, and Vitamin B17 are often used interchangeably, though they refer to slightly different substances. Amygdalin is the naturally occurring cyanogenic glycoside found in foods like apricot kernels. Laetrile is a semi-synthetic derivative of Amygdalin, patented in the 1950s. The “Vitamin B17” label was applied by proponents to classify it as a supplement, but there is no evidence it functions as a true vitamin.
In the United States, the Food and Drug Administration (FDA) has not approved Laetrile or Amygdalin for any medical use, including cancer treatment. The FDA prohibited the interstate shipment of both compounds in 1977, and the U.S. Supreme Court upheld the federal ban on its interstate commerce in 1980. The compound is restricted because it is not recognized as safe and effective, lacking scientific proof of efficacy and posing a risk of serious adverse effects.
The European Food Safety Authority (EFSA) has also issued warnings regarding the consumption of raw apricot kernels due to cyanide toxicity. The regulatory stance across major regions is generally one of restriction and caution, based on a lack of clinical benefit and documented toxicity.
Practical Purchasing Sources and Product Forms
Amygdalin is typically encountered in three main forms: raw kernels, encapsulated supplements, and injectable solutions.
Raw Kernels
The rawest source is bitter apricot kernels, sometimes sold online or in health food stores as a “whole food.” These kernels contain the highest concentration of naturally occurring Amygdalin. Their availability often capitalizes on the ambiguity between food and supplement regulation.
Encapsulated Supplements
Encapsulated supplements, marketed as Amygdalin extract or “B17” capsules, are frequently sourced from international online vendors operating outside of strict regulatory oversight. Purchasing from these sources introduces risks, including variability in product purity and potency, as manufacturing processes are unregulated. Customs officials may also seize these products upon entry due to import restrictions.
Injectable Solutions
Injectable Laetrile is a purified, concentrated solution typically administered intravenously. This form is almost exclusively accessed through specialized clinics or compounding pharmacies in other countries, such as Mexico. While the injectable form is generally considered less toxic than the oral form because it bypasses digestive enzymes, the purity and content of these solutions can be highly inconsistent and unregulated.
Essential Safety and Toxicity Warnings
The primary and most serious health concern associated with Amygdalin and Laetrile is the risk of cyanide poisoning. Amygdalin is a cyanogenic glycoside that releases a cyanide group when metabolized in the body. Upon ingestion, intestinal enzymes, such as beta-glucosidase, break down Amygdalin, leading to the release of hydrogen cyanide (HCN).
HCN is a potent poison that interferes with cellular respiration by inhibiting a key enzyme in the mitochondria, causing cellular hypoxia. Symptoms of mild to moderate cyanide toxicity include nausea, vomiting, headache, dizziness, and confusion. More severe cases involve respiratory distress, seizures, dangerously low blood pressure, coma, and can lead to death.
Oral consumption of raw kernels or encapsulated forms is considered the most dangerous route due to the rapid release of cyanide in the digestive tract. A single 500 mg Laetrile tablet may contain between 2.5 and 25 mg of hydrogen cyanide, and consuming a high number of apricot kernels has been fatal.
The toxic effects are heightened when Amygdalin is consumed alongside foods containing beta-glucosidase, such as certain raw vegetables, or with high doses of Vitamin C. Scientific studies have consistently shown that Amygdalin and Laetrile are ineffective as cancer treatments. Health authorities strongly caution against their use, emphasizing that the risks of severe or fatal cyanide poisoning far outweigh any unproven benefits. The lethal oral dose of cyanide is estimated to be approximately 0.5 to 1.5 mg per kilogram of body weight, which can be easily reached with concentrated products.