Ask KBeauty Verified™

KBeauty Verified™ — K-beauty checked against official records from Korea, the EU and the U.S.

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ChatGPT: 2 Claude: 1 Google · Gemini: 0 Perplexity: 0 Meta AI: 0 Amazon: 0 Others: 1

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ChatGPT2

Claude1

Google · Gemini0

Perplexity0

Meta AI0

Amazon0

Others1

Named by what the crawler says it is; look-alikes we detect are counted under Others. Google · Gemini includes Googlebot, Google’s search crawler, whose index Google also uses for its AI features; other search engines and bots are in Others. AI visibility →

Cysteine HCl

Korean: 시스테인에이치씨엘 · Functions: antioxidant, hair conditioning, hair waving or straightening, reducing

KR South Korea (MFDS)

Restricted MFDS restricted ingredients

Conditions (official MFDS text, Korean):
* 배합한도 : 퍼머넌트웨이브용 제품에 시스테인으로서 3.0~7.5% (다만, 가온2욕식 퍼머넌트웨이브용 제품의 경우에는 시스테인으로서 1.5～5.5%, 안정제로서 치오글라이콜릭애씨드 1.0%를 배합할 수 있으며, 첨가하는 치오글라이콜릭애씨드의 양을 최대한 1.0%로 했을 때 주성분인 시스테인의 양은 6.5%를 초과할 수 없다)

Source: MFDS — cosmetic ingredient use restrictions · checked Oct 17, 2026

EU European Union (CosIng)

No specific rule on file.

US United States (FDA)

No specific rule on file. The FDA regulates few cosmetic ingredients by name; no rule does not mean approval.

Products listing Cysteine HCl

Mise en Scene Hello Bubble Other · $12.59

0 1 1 0 0 0 0 4

Also listed as

Cysteine HCl 시스테인에이치씨엘

Information only, not medical advice. Rules change — always check the linked official source. If you are pregnant, have a skin condition or allergies, ask a dermatologist or pharmacist.

Frequently asked questions

Is Cysteine HCl banned in the European Union?

We found no specific rule for it in the EU's CosIng records. That is not an approval or a safety statement.

Is Cysteine HCl banned in South Korea?

In Korea's MFDS records it is listed as “Restricted” (MFDS — cosmetic ingredient use restrictions). A restricted ingredient is allowed within the stated conditions.

Is Cysteine HCl allowed in cosmetics in the U.S.?

We found no specific rule for it in the FDA's records. That is not an approval or a safety statement.

What is Cysteine HCl used for in cosmetics?

The EU's CosIng inventory lists its functions as: antioxidant, hair conditioning, hair waving or straightening, reducing.

What is Cysteine HCl called on Korean labels?

Korea's MFDS standard Korean name is 시스테인에이치씨엘.

Which K-beauty products contain Cysteine HCl?

1 products we checked list it, for example Mise en Scene Hello Bubble.