I just got a Facebook Sponsored link for KB Skin Whitening pills.

The copy says:

Kyusoku Bihaku - International
The 1st Oral Glutathione Supplement in Free Form formulated with
N-Acetyl-L-Cysteine (NAC) widely recognized as the glutathione.
Contact Us:
+63917 - 800 58 36

I looked up glutathione in Wikipedia.

Glutathione has recently been used as an inhibitor of melanin in the cosmetics industry. In countries like Japan and the Philippines, this product is sold as a whitening soap. Glutathione competitively inhibits melanin synthesis in the reaction of tyrosinase and L-DOPA by interrupting L-DOPA's ability to bind to tyrosinase during melanin synthesis. The inhibition of melanin synthesis was reversed by increasing the concentration of L-DOPA, but not by increasing tyrosinase. Although the synthesized melanin was aggregated within 1 h, the aggregation was inhibited by the addition of glutathione. These results indicate that glutathione inhibits the synthesis and agglutination of melanin by interrupting the function of L-DOPA."

Okay, that's through the skin. Fortunately, it looks like it's essentially useless taken orally:

Raising GSH levels through direct supplementation of glutathione is difficult. Research suggests that glutathione taken orally is not well absorbed across the gastrointestinal tract. In a study of acute oral administration of a very large dose (3 grams) of oral glutathione, Witschi and coworkers found "it is not possible to increase circulating glutathione to a clinically beneficial extent by the oral administration of a single dose of 3 g of glutathione."

I feel a little better about that, I think. (If that's what's actually in it, it's probably harmless. Maybe.) Still disturbing that people are taking pills to lighten their skin.

The phone number is in the Philippines, which matches up with the address of the main office in Makati City. It seems at least slightly sneaky that the package has both a Japanese-like name and some katakana on the package. Guess Japan has a better reputation than the Philippines when it comes to random patent medicines.