L-Cysteine 500 mg
by NOW · tablet or pill · 100 tablets
- On the market (NIH)
- UPC 7 33739 00077 4
- DSLD label 210355
- Serving 1 tablet
L-Cysteine 500 mg by NOW lists 3 ingredients, 3 with an amount per serving of 1 tablet, such as 60 mg of vitamin C, 10 mg of vitamin B6 and 500 mg of L-cysteine hydrochloride. Its current label entered the NIH Dietary Supplement Label Database on December 22, 2019.
What is in L-Cysteine 500 mg?
Each row as the label prints it, per serving of 1 tablet. The capsule beside an amount places it among every product in the NIH database that lists the same ingredient: the bar is the middle half of their amounts, the line in it the median, the whiskers the 10th and 90th percentiles; the green tick is the FDA Daily Value and the red dashed tick the adult upper limit (IOM).
| Ingredient | Amount | % DV | Among products listing it |
|---|---|---|---|
| Vitamin Cas Ascorbic Acid | 60 mg | 67% | 65% of 18,583 products listing vitamin C give more (median 100 mg). Per day at the most servings: 180 mg. |
| Vitamin B6as Pyridoxine HydrochlorideVitamin B-6 (Form: from Pyridoxine HCl) | 10 mg | 588% | Higher than 55% of 15,277 products listing vitamin B6 (median 6 mg). Per day at the most servings: 30 mg. |
| L-Cysteine HydrochlorideL-Cysteine (Form: from L-Cysteine Hydrochloride) | 500 mg | Higher than 90% of 516 products listing cysteine (median 85 mg). Per day at the most servings: 1,500 mg. |
Source: NIH ODS Dietary Supplement Label Database, label 210355 (entered December 22, 2019), version 9.4.0. See the label on DSLD. Amounts are what the maker printed; DSLD does not test products. Daily Values: the FDA's Daily Value page.
Is that a lot?
The rows in the top or bottom tenth of the products that list the same ingredient, and any above the adult upper limit at the most servings a day the directions give:
- Its 500 mg of L-cysteine hydrochloride (filed by NIH under cysteine) is higher than 90% of the 516 cysteine products that print an amount; 27 list more.
The NIH database records 1 to 3 servings a day from the label's directions; its % Daily Values are for adults and children 4 or more years of age. The directions as printed are further down this page.
The Tolerable Upper Intake Level is the most of a nutrient per day, from food, water and supplements together, that is likely to pose no risk for almost all adults (Institute of Medicine, 2011). It does not apply under medical supervision. This page compares labels; it is not medical advice.
Sources: amounts from the DSLD label; Daily Values from 21 CFR 101.9(c)(8)(iv); adult upper limits from the Institute of Medicine's DRI summary tables (2011). How positions are computed.
Which products have the closest formulas?
1 product lists the very same ingredients; the nearest amounts come first.
- L-Cysteine 500 mgLuckyVitamin same ingredients
- L-Cysteine Free Form 500 mgVitamin World · off the market 1 shared, 57% alike
- L-Cysteine 500 mgDouglas Laboratories 1 shared, 57% alike
- L-Cysteine 500 mgVitamin World 1 shared, 57% alike
- Pancreatin-EIntensive Nutrition · off the market 1 shared, 57% alike
- L-Cysteine-SNutri-West 1 shared, 57% alike
Source: ingredient lists of every product's current label in DSLD (version 9.4.0); similarity weights each shared ingredient by how rare it is.
What does the label say about taking it?
Quoted from the label as DSLD transcribed it: the maker's words, including any claim about what the product does, which the FDA has not evaluated and PlainVitamins does not endorse.
- Directions
- Suggested Usage: Take 1 tablet 1 to 3 times daily as needed.
- Warnings
- Caution: For adults only.
- Consult physician if pregnant/nursing, taking medication, or have a medical condition.
- Keep out of reach of children.
- Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.
- Allergens and what it does not contain
- Non-GMO
- Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients.
- Storage
- Store in a cool, dry place after opening.
Source: label statements in DSLD label 210355.
What else is on the label?
Other ingredients: Microcrystalline Cellulose, Vegetarian Coating, Silicon Dioxide, Magnesium Stearate, Citric Acid.
Seals and symbols as the label prints them (the maker's; a certifier's own list confirms a seal): Triangle K; GMP Quality Assured.
How many labels does L-Cysteine 500 mg have?
3 labels are on file under this name since October 1, 2012: other sizes, label designs and reformulations. The current one leads this page.
- Label 210355 (current) Entered December 22, 2019 · on the market · 100 tablets · UPC 7 33739 00077 4
- Label 55094 Entered December 23, 2015 · off the market July 24, 2018 · 100 tablets · UPC 7 33739 00077 4
- Label 13300 Entered October 1, 2012 · off the market November 24, 2015 · 100 tablets · UPC 7 33739 00077 4
Source: DSLD label entry and market events, version 9.4.0 (labels entered through September 25, 2025).
Who makes it?
The label names NOW Foods (manufacturer), Bloomingdale, IL. All NOW products.