L-cystine explained: what it is and how it forms

The NIH says cystine forms when sulfur-containing parts of cysteine undergo oxidation. Steel Bite Pro lists it inside a 571 mg proprietary blend, with a serving of 2 capsules. One product we reviewed lists L-cystine, and no labels print its individual amount.

SSOHOHOONH₂NH₂SSOHOHOONH₂NH₂
What it is
Amino acid
In the products we reviewed
1, its label does not print the amount

What L-cystine is

  • Cystine forms when sulfur-containing parts of cysteine undergo oxidation.1

How much L-cystine each product gives

Per serving, as each label prints it

Amount not printed: the dashed line shows the most it can be, the whole blend

Steel Bite ProNot printed · at most 571 mg

The product we reviewed that lists L-cystine

ProductForm and servingL-cystine per servingOur scorePrice a bottleBuy
Steel Bite Pro#6 in oral health supportCapsules2 capsulesNot printedIn a 571 mg proprietary blend8.3$49Check price
Prices checked Oct 11, 2026

Questions people ask

What is L-cystine?

L-cystine forms when sulfur-containing parts of cysteine undergo oxidation, according to the NIH.

How are L-cystine and L-cysteine related?

Cystine forms from cysteine, according to the NIH. The NIH describes this as sulfur-containing parts of cysteine undergoing oxidation.

Which supplements we reviewed contain l-cystine?

Steel Bite Pro lists L-cystine. It comes in capsules.

How much L-cystine is in Steel Bite Pro?

The individual L-cystine amount is not printed. It is listed inside a 571 mg proprietary blend, and the serving is 2 capsules.

Sources

The products, amounts and prices come from each product's label and checkout, as its review shows them. AI drafts our pages from listed sources, figures are checked against them, and we have not tried the products.

  1. 1NIH National Cancer Institute Thesaurus, Cystineevsexplore.semantics.cancer.gov/evsexplorechecked