Vitamin B17 is a commonly used name for a chemical called amygdalin. Typically sourced from apricot pits and bitter almonds, amygdalin is used to make laetrile (a compound said to aid in the treatment of cancer). Although they’re frequently referred to as “vitamin B17,” neither amygdalin nor laetrile is truly a B vitamin.

Uses for Vitamin B17

Laetrile is often claimed to treat cancer naturally. It is not approved by the U.S. Food and Drug Administration as a treatment for cancer, or any other medical condition.

Some proponents of laetrile suggest that cancer occurs as a result of a vitamin deficiency. Such proponents claim that consumption of the so-called vitamin B17 can reverse this deficiency and, in turn, aid in the treatment or prevention of cancer. However, as the National Cancer Institute (NCI) states, there is no evidence that laetrile is needed by the body or that laetrile can act as a vitamin in animals or humans.

Laetrile is also purported to protect against conditions like high blood pressure and arthritis.

Sources of Vitamin B17

Amygdalin is found naturally in raw nuts and in the pits of many fruits. It’s also present in plants like lima beans, clover, and sorghum.

Side Effects & Safety Concerns

Amygdalin produces cyanide, which is a toxic substance. Cyanide is thought to be primary cancer-fighting component of laetrile and amygdalin. It’s said that the cyanide released in the body by these substances can kill off cancer cells.

Developed in the United States in the 1950s, laetrile is claimed to act as a nontoxic form of amygdalin. Still, laetrile has been found to trigger a range of side effects similar to those of cyanide poisoning.

Use of laetrile is associated with the following side effects: blue coloring of the skin, confusion, difficulty walking, dizziness, droopy upper eyelids, headache, liver damage, low blood pressure, nausea, nerve damage, and vomiting.

Cyanide poisoning can be life-threatening and may result in death.

According to the NCI, use of laetrile is also associated with increased risk of coma or death.

There’s concern that vitamin C may boost the amount of cyanide released from laetrile in the body and, as a result, lead to increased risk of toxicity.

Research on Vitamin B17

Claims that laetrile or amygdalin can benefit cancer patients are not supported by sound clinical data, according to a report published in the Cochrane Database of Systematic Reviews in 2011.

For this report, scientists analyzed 69 previously published studies evaluating the supposedly anti-cancer effects and possible adverse effects of laetrile and amygdalin. However, none of these studies was found to be sufficiently rigorous to meet the reviewers’ criteria.

In their conclusion, the report’s authors note that consumption of laetrile or amygdalin carries a considerable risk of serious adverse effects resulting from cyanide poisoning. To that end, the authors state that the “risk-benefit balance of laetrile or amygdalin as a treatment for cancer is therefore unambiguously negative.”

In several preliminary studies published in recent years, researchers have observed that amygdalin may possess some anti-cancer properties.

A study published in Immunopharmacology and Immunotoxicology in 2013, for instance, indicates that amygdalin may protect against cervical cancer. In tests on human cells, researchers observed that amygdalin may combat cervical cancer by inducing apoptosis (a type of programmed cell death essential for stopping the proliferation of cancer cells).

In addition, two preliminary studies published in PLoS One in 2014 found that amygdalin may fight bladder cancer, in part by blocking tumor growth.

Further research is needed before amygdalin can be recommended for the prevention or treatment of cancer.

Alternatives to Vitamin B17

While there’s no known way to prevent cancer, certain practices may help lower your cancer risk.

These practices include avoiding smoking and tobacco use, getting screened for precancerous conditions, following a healthy diet, exercising regularly, and maintaining a healthy weight.

If you’re thinking of using vitamin B17 for the prevention or treatment of cancer, it’s crucial to consult your physician first. Self-treating and avoiding or delaying standard care can have serious consequences.


Chen Y, Ma J, Wang F, Hu J, Cui A, Wei C, Yang Q, Li F. “Amygdalin induces apoptosis in human cervical cancer cell line HeLa cells.” Immunopharmacol Immunotoxicol. 2013 Feb;35(1):43-51.

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 Aug 19;9(8):e105590.

Makarević J, Rutz J, Juengel E, Kaulfuss S, Tsaur I, Nelson K, Pfitzenmaier J, Haferkamp A, Blaheta RA1. “Amygdalin influences bladder cancer cell adhesion and invasion in vitro.” PLoS One. 2014 Oct 15;9(10):e110244.

Milazzo S, Ernst E, Lejeune S, Boehm K, Horneber M. “Laetrile treatment for cancer.” Cochrane Database Syst Rev. 2011 Nov 9;(11):CD005476.

Milazzo S, Lejeune S, Ernst E. “Laetrile for cancer: a systematic review of the clinical evidence.” Support Care Cancer. 2007 Jun;15(6):583-95.

National Cancer Institute. “Laetrile/Amygdalin (PDQ)—Patient Version.” June 2015.

Song Z, Xu X. “Advanced research on anti-tumor effects of amygdalin.” J Cancer Res Ther. 2014 Aug;10 Suppl 1:3-7.

Disclaimer: The information contained on this site is intended for educational purposes only and is not a substitute for advice, diagnosis or treatment by a licensed physician. It is not meant to cover all possible precautions, drug interactions, circumstances or adverse effects. You should seek prompt medical care for any health issues and consult your doctor before using alternative medicine or making a change to your regimen.