L-cysteine
Scientific names: 2-Amino-3-mercaptopropanoic acid
Alternate names: 2-Amino-3-mercaptopropionic Acid, 2-Amino-3-sulfanylpropanoic Acid, Chlorhydrate de Cystéine, Cys, Cysteine, Cystéine, Cysteine Hydrochloride, Cystine, Hydrochlorure de Cystéine, L-Cys, L-Cystéine, L-Cysteine HCl, L-Cystéine HCl, L-Cystine
Actions: General, Anti-alcohol, Anti-cancer, Anti-inflammatory, Anti-obesity, Antioxidant, Neurological
Background
L-cysteine is a type of amino acid, which are the building blocks of proteins. The body makes L-cysteine from another amino acid called methionine.
L-cysteine is naturally found in foods, but because it's made in the body it doesn't need to be consumed in the diet. L-cysteine has antioxidant effects and is used to make up antioxidants such as glutathione.
People use L-cysteine for cancer, diabetes, hangover, stroke, and many other conditions, but there is no good scientific evidence to support these uses.
Don't confuse L-cysteine with N-Acetyl Cysteine (NAC). These are not the same.
L-cysteine is naturally found in foods, but because it's made in the body it doesn't need to be consumed in the diet. L-cysteine has antioxidant effects and is used to make up antioxidants such as glutathione.
People use L-cysteine for cancer, diabetes, hangover, stroke, and many other conditions, but there is no good scientific evidence to support these uses.
Don't confuse L-cysteine with N-Acetyl Cysteine (NAC). These are not the same.
Safety Safety definitions
When taken by mouth: L-cysteine is commonly consumed in foods. But there isn't enough reliable information to know if L-cysteine is safe when used in larger amounts as medicine or what the side effects might be.
Surgery: L-cysteine might interfere with blood sugar control during surgery. Stop taking L-cysteine at least 2 weeks before a scheduled surgery.
Special Precautions & Warnings:
Pregnancy and breast-feeding: L-cysteine is commonly consumed in foods. But there isn't enough reliable information to know if L-cysteine is safe to use in larger amounts as medicine while pregnant or breast-feeding. Stay on the safe side and avoid use.Surgery: L-cysteine might interfere with blood sugar control during surgery. Stop taking L-cysteine at least 2 weeks before a scheduled surgery.
Effectiveness
Effective Effectiveness definitions
There is interest in using L-cysteine for a number of purposes, but there isn't enough reliable information to say whether it might be helpful.
Dosing & administration
L-cysteine is naturally found in foods. But as medicine, there isn't enough reliable information to know what an appropriate dose of L-cysteine might be. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult a healthcare professional before using.
Interactions with pharmaceuticals
Medications for diabetes (Antidiabetes drugs)
Interaction Rating=Moderate Be cautious with this combination.
L-cysteine might lower blood sugar levels. Taking L-cysteine along with diabetes medications might cause blood sugar to drop too low. Monitor your blood sugar closely.
Interactions with herbs & supplements
Herbs and supplements that might lower blood sugar: L-cysteine might lower blood sugar. Taking it with other supplements with similar effects might lower blood sugar too much. Examples of supplements with this effect include aloe, bitter melon, cassia cinnamon, chromium, and prickly pear cactus.
Interactions with foods
There are no known interactions with foods.
Products
View all productsPer capsule:
- N-acetylcysteine (NAC) 590 mg equiv. cysteine 438 mg
- Hypromellose
- Microcrystalline cellulose
- Water
- Orthosilicic acid (Silica)
- Magnesium stearate
Practitioner product
Per 35.2 g:
- Cysteine hydrochloride 180.82 mg equiv. cysteine 139 mg
- L-glutamine 2.22 g
- L-leucine 1.67 g
- Lysine hydrochloride 451.02 mg equiv. l-lysine 361 mg
- L-isoleucine 450 mg
- L-valine 450 mg
- L-phenylalanine 200 mg
- L-threonine 200 mg
- L-methionine 120 mg
- L-tyrosine 112.5 mg
- Histidine hydrochloride 185.22 mg equiv. l-histidine 150 mg
- L-aspartic acid 111 mg
- L-proline 111 mg
- L-serine 27.75 mg
- L-alanine 27.75 mg
- Glycine 27.75 mg
- Taurine 11 mg
- Zinc sulphate monohydrate 5.7 mg equiv. zinc 2.08 mg
- Sodium ascorbate (Vitamin C) 22.5 mg equiv. ascorbic acid 20 mg
- d-alpha-Tocopheryl acetate 10.5 mg equiv. vitamin E 10 IU
- Retinol palmitate (Vitamin A) 462 µg equiv. vitamin A 252 µg equiv. vitamin A 833.33 IU
- Cyanocobalamin (Vitamin B12) 2 µg
- Carnitine tartrate 10.99 mg equiv. l-carnitine 7.5 mg
- Potassium citrate 402.65 mg equiv. potassium 145.75 mg
- Magnesium citrate 166.67 mg equiv. magnesium 26.99 mg
- Ferrous fumarate 4.6 mg equiv. iron 1.5 mg
- Manganese sulphate monohydrate 10.14 mg equiv. manganese 0.33 mg
- Selenomethionine 28.59 µg equiv. selenium 11.54 µg
- Copper sulfate pentahydrate 654.7 µg equiv. copper 167 µg
- Molybdenum trioxide 10.56 µg equiv. molybdenum 8 µg
- Chromium picolinate 105.6 µg equiv. chromium 13 µg
- Potassium iodide 22 µg equiv. iodine 17 µg
- Borax 2.20 mg equiv. boron 250 µg
- Choline bitartrate 80.89 mg equiv. choline 33.25 mg
- Nicotinamide (Vitamin B3) 3.25 mg
- Pyridoxine hydrochloride (Vitamin B6) 771 µg equiv. pyridoxine 650 µg
- Cholecalciferol 1.65 µg equiv. vitamin D3 66 IU
- Riboflavin (Vitamin B2) 500 µg
- Thiamine nitrate (Vitamin B1) 616 µg equiv. thiamine 500 µg
- Folic acid 31.27 µg
- Levomefolate glucosamine (Activated folate) 8.34 µg equiv. levomefolic acid 4.5 µg
- Biotin 50 µg
- Calcium pantothenate (Vitamin B5) 3.55 mg equiv. pantothenic acid 3.25 mg
- Phytomenadione (Vitamin K1) 10 µg
- Glucose monohydrate 12.5 g
- Sunflower lecithin 250 mg
- Magnesium glycerophosphate 50.12 mg equiv. magnesium 6.27 mg
- Calcium glycerophosphate 392.73 mg equiv. calcium 75.01 mg
- Calcium phosphate 62.62 mg equiv. calcium 24.99 mg
Practitioner product
Per 4 g:
- Cysteine hydrochloride 181 mg equiv. cysteine 125 mg
- Brassica oleracea var. italica ext. 200 mg
- L-glutamine 750 mg
- Brassica oleracea var. italica ext. 150 mg
- Curcuma longa ext. 85 mg
- Taurine 500 mg
- L-methionine 125 mg
- L-glycine 500 mg
- Choline bitartrate 250 mg
- Inositol 200 mg
- Potassium sulphate 150 mg equiv. potassium 67 mg
Practitioner product
Per tablet:
- Cysteine hydrochloride 65 mg equiv. cysteine 50 mg
- L-methionine 100 mg
- Curcumin (Turmeric) equiv. curcuminoids 9 mg
- Choline bitartrate 200 mg
- Inositol 150 mg
- Glutamine 100 mg
- Magnesium citrate 370.4 mg equiv. magnesium 60 mg
- Taurine 100 mg
- Potassium sulphate 60.2 mg equiv. potassium 27 mg
- L-glycine 100 mg
- Zinc citrate dihydrate 16 mg equiv. zinc 5 mg
- Selenomethionine 124 μg equiv. selenium 50 μg
- Pyridoxal 5-phosphate monohydrate (P5P) 5.41 mg equiv. pyridoxine 3.45 mg
- Calcium folinate (Activated folate) 50 μg equiv. folinic acid 46.3 μg
- Molybdenum trioxide 37.5 μg equiv. molybdenum 25 μg
- Manganese amino acid chelate 25 mg equiv. manganese 2.5 mg
- Mecobalamin (Vitamin B12) 50 μg
- Riboflavin 5-phosphate sodium (Activated B2) 5 mg equiv. riboflavin 3.8 mg
- Tocotrienols complex - palm (Vitamin E) 1 mg
Practitioner product
Per 37 g:
- Cysteine hydrochloride 45 mg equiv. cysteine 31.04 mg
- Glutamine 2.22 g
- L-leucine 1.68 g
- Lysine hydrochloride 451.03 mg equiv. lysine 361 mg
- L-isoleucine 450 mg
- L-valine 450 mg
- L-phenylalanine 200 mg
- L-threonine 200 mg
- L-methionine 120 mg
- L-tyrosine 112.5 mg
- Histidine hydrochloride 185.25 mg equiv. l-histidine 150 mg
- L-aspartic acid 111 mg
- L-proline 111 mg
- L-serine 27.75 mg
- Glycine 27.75 mg
- L-alanine 27.75 mg
- Taurine 11 mg
- Levocarnitine tartrate (L-carnitine) 10.99 mg equiv. levocarnitine 7.5 mg
- Potassium citrate 402.6 mg equiv. potassium 145.74 mg
- Magnesium citrate 167.09 mg equiv. magnesium 27 mg
- Magnesium glycerophosphate 49.99 mg equiv. magnesium 6.25 mg
- Calcium phosphate 62.64 mg equiv. calcium 25 mg
- Calcium glycerophosphate 393.27 mg equiv. calcium 75 mg
- Ferrous fumarate 45.6 mg equiv. iron 1.5 mg
- Manganese sulphate monohydrate 1.02 g equiv. manganese 330 µg
- Zinc sulphate monohydrate 5.74 mg equiv. zinc 2.08 mg
- Selenomethionine 28.64 µg equiv. selenium 11.54 µg
- Copper sulfate pentahydrate 656.27 µg equiv. copper 167 µg
- Molybdenum trioxide 12 µg equiv. molybdenum 8 µg
- Chromic chloride hexahydrate 46.95 µg equiv. chromium 9.16 µg
- Chromium picolinate 30.89 µg equiv. chromium 3.84 µg
- Potassium iodide 22.25 µg equiv. iodine 17 µg
- Borax 2.2 mg equiv. boron 250 µg
- Choline bitartrate 80.84 mg equiv. choline 33.25 mg
- Sodium ascorbate (Vitamin C) 22.5 mg equiv. ascorbic acid 20 mg
- dl-alpha-Tocopheryl acetate 10 mg equiv. vitamin E 10 IU
- Nicotinamide (Vitamin B3) 3.25 mg
- Retinol palmitate 418.58 µg equiv. vitamin A 767 IU
- Pyridoxine hydrochloride (Vitamin B6) 790 µg equiv. pyridoxine 650 µg
- Cholecalciferol 1.65 µg equiv. vitamin D3 66 IU
- Riboflavin (Vitamin B2) 500 µg
- Thiamine nitrate (Vitamin B1) 616.83 µg equiv. thiamine 500 µg
- Folic acid 31.27 µg
- Biotin 50 µg
- Calcium pantothenate (Vitamin B5) 3.53 mg equiv. pantothenic acid 3.25 mg
- Phytomenadione (Vitamin K1) 10 µg
- Cyanocobalamin (Vitamin B12) 2 µg
- Glucose monohydrate (Dextrose) 12.5 g
- Sunflower lecithin 250 mg
- Levomefolate glucosamine (Activated folate) 8 µg equiv. levomefolic acid 4.5 µg
- Medium Chain Triglycerides (powder) (MCT) 3 g
Practitioner product
Per tablet:
- Cysteine hydrochloride 29 mg equiv. cysteine 20 mg
- L-glutamine 100 mg
- Ascorbic acid (Vitamin C) 20 mg
- Selenomethionine 124 μg equiv. selenium 50 μg
- Zinc amino acid chelate 25 mg equiv. zinc 5 mg
- Silybum marianum ext. 85.7 mg
- Brassica oleracea var. italica ext. 75 mg
- L-glycine 150 mg
- Taurine 200 mg
- L-methionine 100 mg
- Choline bitartrate 200 mg
- Inositol 100 mg
- L-ornithine monohydrochloride 10 mg equiv. ornithine 7.84 mg
- Citrus bioflavonoids extract 30 mg
- Molybdenum trioxide 60 μg equiv. molybdenum 40 μg
- Copper gluconate 42.86 μg equiv. copper 6 μg
- Pyridoxal 5-phosphate (P5P) 7.84 mg equiv. pyridoxine 5 mg
- Calcium folinate (Activated folate) 69.44 μg equiv. folinic acid 50 μg
- Cyanocobalamin (Vitamin B12) 50 μg
- Glutathione 20 mg
- Manganese amino acid chelate 250 μg equiv. manganese 25 μg
Practitioner product
Per capsule:
Practitioner product
Per tablet:
- Cysteine hydrochloride 21.74 mg equiv. cysteine 15 mg
- Thiamine hydrochloride (Vitamin B1) 50 mg equiv. thiamine 43.26 mg
- Nicotinamide (Vitamin B3) 220 mg
- Pyridoxine hydrochloride (Vitamin B6) 50.13 mg equiv. pyridoxine 40 mg
- Riboflavin 5-phosphate sodium (Activated B2) 27.4 mg equiv. riboflavin 20 mg
- Mecobalamin (Vitamin B12) 500 μg
- Selenomethionine 64.58 μg equiv. selenium 26 μg
- Retinol acetate 884 μg equiv. vitamin A 750 μg RE
- Nicotinic acid (Vitamin B3) 5 mg
- Calcium pantothenate (Vitamin B5) 100 mg equiv. pantothenic acid 88 mg equiv. calcium 8.4 mg
- Calcium folinate (Activated folate) 278 μg equiv. folinic acid 200 μg
- Levomefolate calcium (Activated folate) 216.56 μg equiv. levomefolic acid 200 μg
- Calcium ascorbate dihydrate (Vitamin C) 121 mg equiv. ascorbic acid 100 mg equiv. calcium 11.4 mg
- Cholecalciferol 2.5 μg equiv. vitamin D3 100 IU
- d-alpha-Tocopheryl acid succinate 28 mg equiv. vitamin E 34 IU
- Tocopherols concentrate - mixed (low-alpha type) 13.5 mg
- R,S-alpha lipoic acid 10 mg
- Biotin 150 μg
- Ananas comosus (Bromelain) 6 mg
- Choline bitartrate 40 mg
- L-glutamine 40 mg
- Citrus bioflavonoids extract 5 mg
- Inositol 25 mg
- Lecithin 15 mg
- Rutin (Rutoside) 10 mg
- Taurine 85 mg
- Chromium nicotinate 208.34 μg equiv. chromium 25 μg
- Potassium iodide (Iodine) 40.55 μg equiv. iodine 31 μg equiv. potassium 9.55 μg
- Magnesium phosphate pentahydrate 48.4 mg equiv. magnesium 10 mg
- Manganese gluconate 438.6 μg equiv. manganese 50 μg
- Potassium phosphate monobasic 48.73 mg equiv. potassium 14 mg
- Zinc gluconate 109.88 mg equiv. zinc 14.35 mg
- Molybdenum trioxide 75 μg equiv. molybdenum 50 μg
- Rosa canina powder 10 mg
- Pyridoxal 5-phosphate monohydrate (P5P) 10 mg equiv. pyridoxine 6.38 mg
- Citrus bioflavonoids extract 5 mg
- Lysine hydrochloride 35 mg equiv. lysine 28 mg
- Cupric citrate hemipentahydrate 17 μg equiv. copper 6 μg
Practitioner product
Per capsule:
- Cysteine hydrochloride monohydrate 10.5 mg equiv. cysteine 7.25 mg
- Chromium chloride hexahydrate 821 μg equiv. chromium 160 μg
- Chromium picolinate 121 μg equiv. chromium 15 μg
- Alpha lipoic acid 33.5 mg
- Nicotinamide (Vitamin B3) 10 mg
- Glutamine 10 mg
- Glycine 10 mg
- Cinnamomum verum ext. 75 mg
- Ubidecarenone (Coenzyme Q10) 25 mg
- Momordica charantia ext. 100 mg
Practitioner product
Per 1 g:
- N-acetylcysteine (NAC) 955 mg
- Natural lemon lime flavour
- Thaumatin
- Silicon dioxide
Practitioner product
Per 1 g:
- N-acetylcysteine (NAC) 940 mg
- Beta vulgaris (root) powder (Beetroot)
- Fragaria chiloenis (juice) powder (Beach strawberry)
- Euterpe oleracea (berry) ext. (Acai)
- Aristotelia chilensis (Maqui berry)
- Garcinia mangostana (fruit)
- Lycium barbarum (fruit)
- Natural strawberry flavour
- Thaumatin
- Silicon dioxide
- Punica granatum
- Rubus idaeus (fruit) juice
Practitioner product
Practitioner product
Per 1 g:
- N-acetylcysteine (NAC) 900 mg
- Natural pineapple flavour
- Natural coconut flavour
Practitioner product
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This monograph was last reviewed on 31/07/2024 10:00:00. Monographs are reviewed and/or updated multiple times per month and at least once per year.
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