PlainVitamins

amino acid

Cysteine supplements

Half of the 516 cysteine supplements in the NIH label database that print an amount list 85 mg or less per serving; the middle half list 30 mg to 200 mg (DSLD version 9.4.0, January 2026). The 21 products whose only supplement ingredient is cysteine list a median of 500 mg.

Products listing it
753516 print an amount; 236 list it inside a blend without an amount
Median per serving
85 mgmiddle half 30 mg to 200 mg

How much cysteine do supplements contain?

The median product lists 85 mg per serving. One in ten lists 8 mg or less, one in ten 468 mg or more. The amount printed most often is 50 mg (73 products).

Products by amount of cysteine per serving

516 products, log scale; extreme 0.2% at each end left out of the drawing.

Cysteine: products by amount per serving0.03 mg1 mg10 mg100 mg
Cysteine: products by amount per serving0.03 mg0.3 mg3 mg30 mg300 mg
Cysteine: products by amount per serving0.01 mg0.1 mg1 mg3 mg10 mg100 mg1,000 mg
Cysteine: products by amount per serving0.01 mg0.1 mg1 mg3 mg10 mg30 mg100 mg1,000 mg
Cysteine: products by amount per serving0.01 mg0.03 mg0.1 mg0.3 mg1 mg3 mg10 mg30 mg100 mg300 mg1,000 mg
The amounts printed most often
Amount per servingProductsFor example
50 mg73 LifeEssence (Pure Essence Labs); Men's Multiple (Radiance Select); Maximum Anti-Oxidant Formula (Radiance)
100 mg66 Nails (Viva Vitamins); Great Hair (Vitabase); Super Antioxidant Formula (Vitabase)
200 mg33 Ultra-Guard Low Allergenicity Antioxidant (Douglas Laboratories); Hair, Skin, & Nail essentials (Healthy Choice Naturals); Basic Scavengers (Metabolic Maintenance)
500 mg23 L-Cysteine 500 mg (Douglas Laboratories); L-Cysteine 500 mg (Vitamin World); Metabolic Matrix (Energetix)
150 mg22 Recon (MusclePharm); Redox (Douglas Laboratories); Dextox In Guard Tabsules (Perque)
10 mg21 30 Day Beauty Regimen (Bronson); Amino Acids Formula (Martin Avenue Pharmacy); Oxy-5000 Forte (AB American Biologics)
5 mg14 NSAID Support (The Professional Series); NSAID Rx Depletion (Martin Avenue Pharmacy); Bromelain Plus CLA (Biotics Research Corporation)
25 mg13 Curcumax (Integrative Therapeutics); Growth Vitamins Vanilla Flavored (The Beard Club); Essential Vitamins, Minerals & Antioxidants (Williams Nutrition)
30 mg13 Max-Amino Caps with Vitamin B6 (Country Life); UltraClear Vanilla Flavor (Metagenics); VitalShake (VitalBulk)
250 mg10 Premium Soy Protein Isolate Powder Chocolate (Vitamin World); Added Protection III (Douglas Laboratories); Added Protection III (Without Copper And Iron) (Douglas Laboratories)

Source: Supplement Facts rows of every product's current label, NIH ODS Dietary Supplement Label Database version 9.4.0; amounts in one measure (weight).

Which products list the most cysteine?

On-market products, per serving, with a plausible amount: the rule leaves out likely entry slips, such as an amount far beyond every other label with no %DV or strength on the label to back it (each product page still shows its own amount, marked).

Have the amounts changed over the years?

Products whose current label entered DSLD in 2011 list a median of 50 mg; those entered in 2025, 80 mg.

Median cysteine per serving by the year the label entered DSLD (years with 20+ products)
YearProductsMedian per serving
20112150 mg
201248150 mg
20138450 mg
201426195 mg
201723100 mg
20192360 mg
20205092.5 mg
202130100 mg
20223267.5 mg
20233950 mg
20246050 mg
20253880 mg

Source: DSLD label entry dates and amounts, current labels.

In which products and brands?

Products listing cysteine by DSLD product type

Cysteine by product typeOther Combinations433Amino acid/Protein55Botanical with Nutrients27Botanical1
Cysteine by product typeOther Combinations433Amino acid/Protein55Botanical with Nutrients27Botanical1
Cysteine by product typeOther Combinations433Amino acid/Protein55Botanical with Nutrients27Botanical1
Cysteine by product typeOther Combinations433Amino acid/Protein55Botanical with Nutrients27Botanical1
Cysteine by product typeOther Combinations433Amino acid/Protein55Botanical with Nutrients27Botanical1

Brands listing it most: Douglas Laboratories (33), Nature's Plus (22), Metagenics (13), Nutri-West (11), Vitamin World (11), DaVinci Laboratories Of Vermont (11), NaturesPlus (11), Metabolic Nutrition (10), Integrative Therapeutics (8), Natural Factors VegiDay (8).

Every product listing cysteine

753 products, A to Z by name (page 8 of 16), each with the amount its label prints; an amount far outside what other labels print is marked as a possible slip.

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