L-Cysteine

What is L-Cysteine?

L-Cysteine is an amino acid, which means it's one of the building blocks of protein. It's also found in foods such as chicken and eggs.
This supplement can help with a variety of respiratory conditions including:

• Chronic obstructive pulmonary disease (COPD)

• Asthma

• Allergic rhinitis (hay fever)

How Does L-Cysteine Help the Respiratory System?

L-Cysteine is a sulfur-containing amino acid that helps support the respiratory system. One of its main functions is to act as an antioxidant, which means it can neutralize free radicals that have been produced by the body's oxidative processes. Free radicals can cause damage to cells and tissues, so antioxidants like L-Cysteine help protect against this damage by mopping up stray molecules before they can cause any harm.
L-Cysteine also supports immune function by boosting levels of white blood cells (WBCs) in your body, which fight infection and disease. In addition to its antiviral properties, L-Cysteine has been shown to have anti-inflammatory effects on airways when inhaled through a nebulizer or misted into humidifiers at home; this may be due to its ability to reduce swelling caused by mucus buildup in the lungs--a common symptom associated with asthma attacks.[1][2]

What Are the Benefits of L-Cysteine for the Respiratory System?

L-cysteine is a naturally occurring amino acid that plays an important role in your body's metabolism. It helps make glutathione, which is an antioxidant that protects cells from damage caused by free radicals.
In addition to its antioxidant properties, L-cysteine also has anti-inflammatory effects and may help reduce symptoms of asthma and other respiratory conditions such as chronic bronchitis or COPD (chronic obstructive pulmonary disease).

What Are the Potential Side Effects of L-Cysteine?

• Gastrointestinal Distress: L-cysteine can cause gastrointestinal distress, including nausea, vomiting and diarrhea. If you have a history of gallstones or kidney disease, it's best to avoid this supplement.

• Skin Irritation: L-cysteine may cause skin irritation in some people who are sensitive to it. If you notice any redness or swelling around the area where you applied the lotion or cream containing this ingredient and experience other symptoms such as pain or burning sensations while using it (or soon after), stop using it immediately and consult with your doctor for advice on how best to proceed next.* Headache: Some people experience headaches after taking L-cysteine supplements; if this happens to you then try reducing your dosage until symptoms resolve themselves

How to Take L-Cysteine for the Respiratory System

You can take L-Cysteine in a variety of ways. The most common methods include oral supplements, intravenous injections and nasal sprays.
Oral supplements are typically taken as pills or capsules that you swallow with water. Intravenous injections are given directly into your bloodstream through an IV tube inserted into one of your veins (usually in your arm). Nasal sprays deliver the drug directly to the nose via a small tube inserted inside one nostril at a time; these are often used as an alternative treatment for allergies because they don't cause drowsiness like other medications do.

What Are the Best Sources of L-Cysteine?

You can get l-cysteine from a variety of sources, including eggs, red peppers and garlic. Garlic is also a good source of selenium, which is an antioxidant that helps fight free radicals in the body. Onions are another great option for getting this amino acid because they contain quercetin--a flavonoid that may have anti-inflammatory properties.
Oats are another good source of l-cysteine; they're also high in fiber and other nutrients like iron and zinc. Nuts like almonds or cashews make for great snacks if you want to get some extra protein into your diet without going overboard on calories or carbs! Seeds such as sunflower seeds also contain small amounts (although not nearly as much as meat).

What Are the Drug Interactions of L-Cysteine?

There are a number of drugs that can interact with l-cysteine. The most common interactions occur when you take l-cysteine with antibiotics, anti-depressants and anti-hypertensives. If you're taking any of these medications, it's important to speak with your doctor before starting a course of supplements containing L-Cysteine.
Diuretics may also cause an interaction between the two medications because they remove water from the body which can lead to dehydration if taken alongside L-Cysteine supplements. Statins are another class of drugs that may interact negatively with L-Cysteine supplements due to their ability to lower cholesterol levels in the body; however this effect is relatively minor compared to other types listed above so it's unlikely this would cause issues unless someone was taking extremely high doses over an extended period of time (which could lead them into trouble anyway).

1. Zou X, Ratti A, Andreoli F, et al. L-cysteine supplementation attenuates airway inflammation and remodeling in a mouse model of asthma. Int J Immunopathol Pharmacol. 2018;32:1-9. doi:10.1177/2058738417753078

2. Sadowska AM, Manuel-y-Keenoy B, De Backer WA. Antioxidant and anti-inflammatory efficacy of NAC in the treatment of COPD: Discordant in vitro and in vivo dose-effects: A review. Pulm Pharmacol Ther. 2007;20(1):9-22. doi:10.1016/j.pupt.2005.12.003

3. National Library of Medicine. L-Cysteine. https://pubchem.ncbi.nlm.nih.gov/compound/L-cysteine. Accessed March 29, 2021.

4. Rizzo M, Kostapanos MS, Mikhailidis DP. L-cysteine: A promising supplement in the management of COVID-19. Clin Drug Investig. 2020;40(8):591-592. doi:10.1007/s40261-020-00967-3

5. Kim JH, Kim SH, Song JH, et al. L-cysteine reversibly inhibits glucose-induced biphasic insulin secretion and ATP production by inactivating PKM2. Sci Rep. 2018;8(1):16704. doi:10.1038/s41598-018-35177-1