Ingredient: L-Cysteine

INCI: L-Cysteine

Sources: Poultry, Dairy Wheat Germ and Oats

Our rating: GOOD

What is L-Cysteine?

L-cysteine, also known as N-acetyl-l-cysteine (NAC) is a semi-essential amino acid cysteine.

It is classified as “semi-essential” – instead of essential – because the body normally produces enough of the amino acid, but requires supplementation sometimes. L-cysteine increases glutathione (the most important natural detoxifier and antioxidant) levels in the body, which is extremely important for lung and brain functions, and liver detoxification. L-cysteine can only be produced when folic acid, vitamin B6 and vitamin B12 are present from the amino acids serine and methionine.

Eggs and dairy products contain significant levels of L-cysteine. The nutrient can also be found in vegetables sources such as broccoli, brussels sprouts, garlic, sprouted lentils, oats, onions and peppers. 

Benefits of L-Cysteine:

L-cysteine helps the skin to defend against sun damage. Together with vitamin C, it helps skin cells to produce the enzymes that protect the p53 gene. This gene is responsible for triggering a series of actions that cause a potentially cancerous cell to undergo a process called apoptosis (death). L-cysteine is also clinically proven to enhance hydroxytyrosol’s inhibitory melanin production effect.

L-cysteine is recommended for acne as it enhances the effectiveness of vitamin B5 or pantothenic acid. Conventional acne treatment using benzoyl peroxide for pimples can cause acne inflammation. A combination of L-cysteine and alpha-lipoic acid reduces redness and itchiness of pimples caused due to acne treatment. Women who have polycystic ovarian syndrome usually develop acne as a symptom. Ingesting an L-cysteine supplement can help skin cells become more sensitive to estrogens and less sensitive to testosterone. This would reduce irritation and redness to the skin.

L-cysteine helps cells in the skin to become more sensitive to estrogen and less sensitive to testosterone (produced in excess when women have polycystic ovarian syndrome). Taking an L-cysteine supplement may be helpful for women who also take the medication Clomid (clomiphene). Results will be less noticeable in women who are not on medication for hormone imbalances.

According to Alternative Medicine Review, L-cysteine plays a pivotal role in the detoxification mechanisms in the body. Ingesting L-cysteine supplements can help restore the glutathione levels depleted by toxins.

Side Effects & Toxicity:

An extremely safe ingredient, L-cysteine has no known toxicity in general use.

Editor’s Note:

Several studies involving HIV patients show that L-cysteine can boost the body’s immune system by replenishing glutathione levels.