[Effects of L-Cysteine] From Skin Whitening to Blemish Management, 3 Benefits of L-Cysteine

Dec 03, 2023KimSunhyo

[Effects of L-Cysteine] From Skin Whitening to

Blemish Management, 3 Benefits of L-Cysteine

L-Cysteine

3 Benefits of L-Cysteine

This content is health information about ingredients and not directly related to a specific product.

Effects of L-Cysteine

1. Whitening and reduces blemishes
2. Increases intracellular glutathione levels
3. Decreases melanin content and inhibits tyrosinase activity

Hello, I am Jinny, a pharmacist.

As you age, you might be concerned about the appearance of freckles and age spots on your face. Commonly referred to as 'spots,' these include blemishes and freckles, and they may differ slightly in terms of their occurrence and appearance, but they share a commonality of being caused by 'excessive melanin pigments.'

If you have such concerns about spots, you should pay attention to 'L-cysteine.' Through research, it has been confirmed that L-cysteine not only contributes to skin whitening and reducing blemishes but also inhibits the action of the enzyme 'tyrosinase,' which is involved in the melanin pigment production process.

Now, let's explore how L-cysteine can be beneficial for skin whitening and the suppression of freckles and age spots through human trials and animal experiments.

1. Whitening and Reduces Blemishes

L-cysteine is a potent antioxidant that is naturally produced in the body and is one of the constituents that make up 'glutathione,' the primary component of 'backok injection' (whitening injection).

In this regard, a human trial was published in the prestigious academic journal J Cosmetics Dermatology in 2022. When 124 female subjects were given 500mg of L-cysteine and L-glutathione daily for 12 weeks, it was confirmed that not only skin whitening but also a significant reduction in the size of facial blemishes occurred.

"The daily oral administration of L-cysteine 500mg and L-glutathione 250mg over 12 weeks was a safe treatment that effectively whitened the skin of Asian women and reduced the size of facial blemishes."

Reference : Duperray, Joël, Sergheraert, Renaud; Chalothorn, Kunyanatt; Tachalerdmanee, Preeyanuch; Perin, Fabrice (2021). The effects of the oral supplementation of L-Cystine associated with reduced L-Glutathione-GSH on human skin pigmentation: a randomized, double-blinded, benchmark- and placebo-controlled clinical trial. Journal of Cosmetic Dermatology, 1-12.

2. Increases Intracellular Glutathione Level

Glutathione is known for its strong antioxidant properties, and it is believed to help eliminate intracellular reactive oxygen species and toxins. This makes it closely related not only to skin whitening but also to anti-aging.

As mentioned earlier, one of the components that make up this glutathione is L-cysteine. So, can taking L-cysteine increase the levels of glutathione in the body?

According to a research paper published in the World Journal of Gastroenterology in 2008, involving 37 patients with severe ulcerative colitis, when N-acetyl-L-cysteine (NAC) was administered for 4 weeks, the levels of glutathione in the body were restored.
*N-acetyl-L-cysteine (NAC): A stable form of L-cysteine.*

"The administration of the antioxidant N-acetyl-L-cysteine (NAC) restored the glutathione levels."

Reference : Guijarro, L. G., Mate, J., Gisbert, J. P., Perez-Calle, J. L., Marín-Jimenez, I., Arriaza, E., Olleros, T., Delgado, M., Castillejo, M. S., Prieto-Merino, D., Lara, V. G., & Peña, A. S. (2008). N-acetyl-L-cysteine combined with mesalamine in the treatment of ulcerative colitis: Randomized, placebo-controlled pilot study. World Journal of Gastroenterology, 14(18), 2851.

3. Decreases Melanin Content and Inhibits Tyrosinase Activity

As mentioned earlier, spots are caused by an excess of melanin pigments, and tyrosinase is a key enzyme responsible for melanin synthesis. Therefore, inhibiting the tyrosinase enzyme to regulate melanin pigment synthesis is considered a crucial step in preventing pigmentation spots.

In a 2004 animal experiment published in Biofactors, it was reported that the group treated with vitamin C, L-cysteine, and vitamin E showed the most effective reduction in melanin content and inhibition of tyrosinase activity.

"The simultaneous treatment of vitamin C, vitamin E, and N-acetyl cysteine in B16 cells was the most effective in reducing melanin content and inhibiting tyrosinase activity."

Reference : Yoko Fujiwara; Yumiko Sahashi; Mitsumi Aritro; Satoko Hasegawa; Koji Akimoto; Shinji Ninomiya; Yasue Sakaguchi; Yousuke Seyama (2004). Effect of simultaneous administration of vitamin C, L-cysteine and vitamin E on the melanogenesis. Biofactors. 21(1-4), 415–418.

Today, through research papers, we've explored the various skin-related benefits of L-cysteine. L-cysteine is a powerful antioxidant and has various other advantages.

According to a paper published in the prestigious journal Molecules, L-cysteine is known to help strengthen hair. It has been shown to delay hair loss caused by specific diseases. Additionally, it offers cardiovascular benefits like reducing arterial stiffness and lowering blood pressure and can act as a potent antioxidant[1].
[1] Clemente Plaza, Noelia; Reig García-Galbis, Manuel; Martínez-Espinosa, Rosa (2018). Effects of the Usage of l-Cysteine (l-Cys) on Human Health. Molecules, 23(3), 575.

While L-cysteine is generally considered a safe ingredient, it should be consumed with caution if you have an underlying medical condition. This is particularly important for diabetes patients, as L-cysteine can potentially worsen insulin function. Excessive consumption can lead to symptoms like nausea, vomiting, and loss of appetite, so it's advisable to adhere to the recommended daily intake.

I hope you have a healthy day both physically and mentally. This was Jinny.

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