L-Cysteine 500 mg Capsules Benefits, Uses and Health Warnings

People supplement with L-cysteine 500 mg capsules for a number of reasons, such as increasing glutathione synthesis, improving hair growth and detoxifying the liver.

Cysteine is an amino acid – a building block of proteins – that is contained in food and can be synthesized by the human body (from the amino acid methionine and other constituents). Some babies and elderly individuals may be unable to synthesize cysteine, which results in its classification as a “semi-essential” amino acid.

According to the University of Maryland Medical Center, when cysteine is taken as a supplement it is usually taken in the form of N-acetyl-L-cysteine, which is converted to cysteine and then to glutathione in the human body. Glutathione is a powerful antioxidant.

L-cysteine and NAC capsules have a long list of uses because they increase the level of glutathione in the body, which can have a number of different therapeutic effects. This article briefly discusses the role of cysteine and gluthatione in the body and then discuses some of the uses of L-cysteine supplements.

Cysteine

Amino Acid

Skin

Hair

Anti- Aging

How It Works:

• Promotes healthy skin, hair & nails
• Aids in the formation of collagen
• Supports protein structure for anti-aging

Dosage:

Between 200 - 500 mg per day

Safety:

Generally Well Tolerated

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Medical Uses of Cysteine Capsules

Healthcare providers administer N-acetyl cysteine intravenously (via IV) to treat a number of conditions, including acetaminophen overdose, Lou Gehrig’s disease (ALS) and kidney failure in the presence of liver disease.

It is also given in combination with nitroglycerine for a variety of respiratory and cardiac conditions. [2] It can be inhaled as an aerosol spray, but this use must be prescribed and overseen by a doctor.

L-Cysteine and NAC are used to prevent and/or treat other conditions and diseases. Some of these uses include treating infantile bile duct obstructions, hyperlipidemia, lysosomal storage disorders, end-stage renal disease, myocardial infarction, various cancers, allergic rhinitis, CFS (chronic fatigue syndrome), fibrosing alveolitis, epilepsy and more.

Further, L-cysteine is sometimes used to reduce complications associated with sports injuries, decrease damage sustained from radiation, inhibit liver damage from excessive alcohol consumption, and detoxify the liver of heavy metals and other toxic substances.

Cysteine is also available as L-cysteine powder and as cysteine/NAC tablets or capsules. [1] The tablets or capsules are sometimes purchased as dietary supplements and do not require a prescription.

Cysteine and Glutathione

Cysteine is involved in the production of glutathione, an antioxidant produced in the body (called an endogenous antioxidant).

Antioxidants are compounds that can neutralize free radicals, which are a type of radical oxygen species. Free radicals have a negative charge and can damage cells, membranes and DNA if left unchecked.

Antioxidants like glutathione can stabilize free radicals by donating an extra hydrogen atom, which will neutralize the free radical by giving it a neutral charge.

Prolonged free radical damage is thought by researchers to play a role in aging and the development of diseases, such as heart disease and cancer.

Low levels of glutathione have been observed in individuals suffering from a number of conditions, including cancer, HIV/AIDS, blood infections, burns and traumas, to name a few.

People use L-cysteine capsules and NAC to support glutathione levels. While glutathione supplements are available, they are commonly digested in the intestinal tract before reaching the blood stream.

Alternatively, NAC is metabolized in the body to form cysteine, which is then used in the production of glutathione.

L-Cysteine Research

NAC is sometimes administered to help breakdown mucus, which is partly why it is used for lung conditions. It is often inhaled to treat chronic and acute lung disorders, but this use has to be prescribed and supervised by a doctor.

Some studies have focused on the effects of NAC on lung function when it is taken orally in pill or capsule form. In general, clinical trials indicate that NAC may be helpful in reducing flare-ups in those suffering from chronic bronchitis, but the results of available studies have been inconsistent. [1]

For example, N-acetyl cysteine orally for four months was observed to improve lung capacity and reduce shortness of breath and coughing in individuals with sulfur mustard-induced bronchitis.

In addition, N-acetyl cysteine was observed to reduce the risk of flare-ups in individuals with acute bronchitis. But the effect of N-acetyl cysteine on chronic bronchitis appears to be time dependent. [2]

NAC has also been investigated for its effect on acute respiratory distress syndrome (ARDS), a condition that can result from injury to the lungs. NAC may help increase glutathione levels in the lungs and help prevent and/or treat damage to the lungs.

In studies, NAC has been observed to help reduce the severity of ARDS symptoms, but not mortality rates. [1]

Additional Uses of L-Cysteine 500mg

Cystic Fibrosis: Cystic fibrosis patients have used L-cysteine supplements to improve their symptoms. Between 500 and 1000 mg has been used daily, divided into either two or three equal doses.

Treating and Preventing the Flu: To prevent the flu, NAC has been taken in two daily doses of 600 mg effervescent tablets for up to 6 months. In this study, individuals who took NAC reported fewer flu symptoms compared to placebo. [1]

Infertility: NAC and L-cysteine are sometimes taken for infertility. Infertility symptoms in females have been improved via L-cysteine supplementation combined with clomiphene citrate (a drug used to treat infertility by stimulating eggs release).

Further, women with histories of miscarriages were observed to increase the likelihood that they would carry a baby past 20 weeks in a study involving NAC administration.

In this study, a daily dose of NAC (600 mg/day) was combined with folic acid supplementation. Researchers observed that NAC capsules combined with folic acid was more effective than folic acid on its own.

In cases of male infertility, NAC administration has been shown to improve sperm quantity and motility. A daily dose of 600 mg has been used for up to 26 consecutive weeks.

L-Cysteine 500 mg Capsules Health Warnings

L-cysteine 500 mg capsules are generally well tolerated by otherwise healthy individuals. In rare cases, side effects like nausea, headaches and diarrhea have been reported. In very rare cases, various other cardiovascular, hepatic, hematologic and other side effects have been noted.

L-cysteine and NAC should only be taken by pregnant women under the supervision of their doctor. N-acetyl cysteine and L-cysteine both cross the placenta, but do not seem to have any negative effects on developing fetuses.

Researchers note that pregnant women should only take NAC when it is clearly indicated, such as in cases of acetaminophen poisoning.

Nursing mothers are not recommended for L-cysteine supplementation because there is not enough clinical data to establish its safety.

L-cysteine may interact with a number of prescription and over-the-counter medications, herbals, lab tests and medical procedures.

To be sure that you are not at risk, please consult with your physician before supplementing with any form(s) of cysteine, including L-cysteine 500 mg capsules.

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