We discussed cinnamic acid, the precursor to caffeic acid, the other day. So let's take a look at caffeic acid and its derivatives today!
Caffeic acid is a powerful anti-oxidant, out-performing almost every other anti-oxidant when tested. It is a possible fungicide, good anti-inflammatory, and may protect skin if applied after sun exposure. It also has anti-mitogenic properties, which is why scientists are studying it as a possible cancer fighter. (A mitogen is a chemical substance that encourages a cell to divide. An anti-mitogenic chemical will discourage a cell from dividing.)
A derivative of chlorogenic acid (composed of esters of caffeic acid and quinic acid), it acts as a low level anti-viral and anti-fungal addition to our creations. It offers anti-bacterial properties, which is one of the reasons it is suggested for acne related products. It's a good anti-inflammatory. And, of course, it is a great anti-oxidant. It is found in blueberry, honeysuckle, and green coffee beans.
Another derivative of chlorogenic acid, it is found in great quantities in sage, rosemary, oregano, thyme, and peppermint. It has been considered a tannin, so oils and extracts containing rosmarinic acid tend to feel drier on the skin.
It is a great anti-inflammatory ingredient, and can behave like AHA (alpha-hydroxy acids) on our skin, reducing the appearance of fine lines and wrinkles. (Although it can lead to thinning of the skin and a slight increase in transepidermal water loss, if we compensate with lots of good moisturizing ingredients, we're fine!) A glycolic extract of rosemarinic acid at about 5% in hair and skin products can help reduce sebum production, and it is considered a fantastic anti-oxidant.