What 4MSK actually is

4MSK is a brightening agent developed through Japanese skincare research. In skincare it is best known as a topical ingredient — something applied to the surface of the skin.

Taking the idea inward

SHIROÉ takes that thinking in a different direction. Rather than sitting on the skin, a 4MSK-Inspired Brightening Complex sits at the centre of a capsule you swallow, alongside L-Glutathione, Vitamin C and Collagen Peptide.

The rest of the formula

The full list, exactly as it appears on the label: L-Glutathione, 4MSK-Inspired Brightening Complex, Vitamin C, Alpha Lipoic Acid, Grape Seed Extract, Collagen Peptide, Niacinamide, Zinc, and the capsule shell.

Per-ingredient amounts are not stated on the label, so they are not claimed here. A short ingredient list is only meaningful if you can read it, which is why it is printed in full on the box and repeated on the product page.

What it supports

The formula is made to support brighter-looking skin, refined skin clarity, a softer and more even-looking complexion, and collagen and skin beauty from within. Nothing here promises a result or a timeframe.