Laetrile (amygdalin or vitamin B17)

Laetrile is promoted as an alternative cancer treatment. There is not enough reliable evidence that it works.

Summary

• Laetrile is a man-made form of amygdalin, a plant substance found in some nuts, plants and seeds of fruit.
• Claims that laetrile or amygdalin can treat cancer are not backed up by research.
• It contains cyanide, a poison and can cause serious side effects.

What laetrile is

Laetrile is a partly man-made (synthetic) form of the natural substance amygdalin. Amygdalin is a plant substance found in raw nuts, bitter almonds, as well as apricot and cherry seeds. Plants like lima beans, clover and sorghum also contain amygdalin.

Some people call laetrile vitamin B17, although it isn’t a vitamin. 

Why people with cancer use it

Laetrile has been used as an anti cancer agent since the 1800’s. It is used either on its own or as part of a programme. This might include following a particular diet, high dose vitamin supplements and pancreatic enzymes.

Although, more recent studies have shown that laetrile can kill cancer cells in certain cancer types there is not enough reliable scientific evidence to show that laetrile or amygdalin can treat cancer. Despite this, it still gets promoted as an alternative cancer treatment.

People who use laetrile believe it might:

• improve their health, energy levels and wellbeing
• detoxify and cleanse the body
• help them to live longer

How you have it

Laetrile is available as:

• an injection (intravenously)
• tablets
• skin lotions
• a liquid to put into the back passage (rectum)

Taking laetrile as tablets has more side effects than having it as an injection. This is because our digestive system breaks down the laetrile and releases cyanide. Cyanide is a type of poison.

Side effects

Laetrile contains cyanide. So the side effects of laetrile are the same as those of cyanide. These include:

• fever
• sickness
• headaches
• dizziness
• liver damage
• drooping eyelids
• a lack of oxygen to the body tissues
• a drop in blood pressure
• nerve damage, causing loss of balance and difficulty walking
• confusion, coma and eventually death

Avoid eating other foods containing amygdalin if you take laetrile as tablets. This may include foods like:

• raw almonds
• carrots
• celery
• apricots
• peaches
• bean sprouts
• beans – mung, lima, butter and other pulses
• nuts
• flax seed
• high doses of vitamin C
• crushed fruit stones or pips

These foods are safe to eat when you’re not taking laetrile because the levels of amygdalin in them are low.

Laetrile may cause further damage to your liver if you have liver problems.