Cysteine is a non-essential amino acid, meaning that it can be made in the human body. It is very important as the sulphur content means that it provides structural support to proteins in the hair, skin, nails, stomach and intestines. Cysteine is made from the amino acid methionine and serine, an in turn, Cysteine is needed to produce the amino acid taurine and the antioxidant enzyme glutathione.

Cysteine is also needed to produce Coenzyme A, which is needed for the release of energy from food.

What it does

  1. Detox and liver protection: Glutathione, which relies on cysteine, is needed for the neutralisation of toxins in the liver. Efficient detoxification ensures that harmful toxic compounds are not able to build up in the liver. Cysteine also has antioxidant properties, which further enhances its liver protective abilities.
  2. Heavy Metal Scavenger:
    Cysteine is able to bind to (chelate) heavy metals, thus aiding their removal from the body.
  3. Antioxidant:
    Cysteine, both alone and as part of glutathione, is a very effective free radical scavenger. It is especially valuable in protecting cell membranes.
  4. Cardiovascular Protectant:
    Through its antioxidant effects, cysteine can prevent oxidation of LDL cholesterol, a known risk factor in heart disease. The more potent form of cysteine, NAC, also significantly lowers lipoprotein A, which appears to be an even greater risk factor in heart disease than cholesterol.

Potential Uses

Liver health Heavy metal poisoning Atherosclerosis
Detox Hair and nails Digestive system protection from damage by NSAIDs

Food sources of Cystein include soybeans, spirulina, beef, pork, chicken, turkey, spirulina, lentils, adzuki beans, baked beans, chickpeas, kidney beans, peas, eggs and garlic.


Cysteine may produce a false positive in diabetic tests for ketone bodies.

Best avoided by children, pregnant women and nursing mothers.

Vitamin C supplementation (ratio of 3:1 Vit C:cysteine) is often recommended when taking l-cysteine to prevent conversion to cystine which hast the potential to form crystal and urinary stones.

If you take metoclopramide or nitroglycerine medication, consult your doctor before taking cysteine.

Leave a Reply