Esthetician Alicia Lartey previously explained to R29 that when retinol is applied to the skin, it goes through several steps before being converted into retinoic acid, which triggers all the amazing skin benefits, like improving texture and tone, minimizing fine lines by boosting collagen production, and reducing breakouts by renewing skin cells. Retinal, on the other hand, requires fewer steps to become retinoic acid, so it works faster — 11 times faster, according to The Inkey List. It’s the retinal that gives this serum its striking yellow color, but don’t worry — it hasn’t gone bad, and though it’s a little reminiscent of a turmeric face mask, it absorbs instantly and won’t stain your skin. I can vouch for that.