Kerasyn™ (L-Cysteine) and Sulfur Allergy

Regarding your question about Kerasyn™ (L-Cysteine) and its suitability for someone with a sulfur allergy when used in shampoo:

Kerasyn™ is L-Cysteine, an amino acid. L-Cysteine does contain a sulfur atom as part of its chemical structure. This is why the product has a characteristic sulfide odor, as mentioned.

However, it is important to understand that what is commonly referred to as a "sulfur allergy" is usually an allergy to specific sulfur-containing compounds, most often:

• Sulfites: Preservatives found in foods and medications.
• Sulfonamides: A class of antibiotics (sulfa drugs).

L-Cysteine is chemically different from sulfites and sulfonamides. An allergy to sulfites or sulfonamides does not automatically mean a person will be allergic to L-Cysteine. However, a direct allergy to L-Cysteine is also possible, though less common.

Therefore, while Kerasyn™ (L-Cysteine, 100%) does contain sulfur as a component of the L-Cysteine molecule, its safety for someone with a sulfur allergy is a medical question. It is strongly recommended that the individual consult with a doctor or allergist who is familiar with their specific allergy to determine if using products containing L-Cysteine is appropriate for them.