How does it work?
First and foremost, caffeine is produced by plants and occurs naturally in coffee and tea. Taken internally, caffeine stimulates the nervous system and is considered safe in moderate amounts. However, large amounts of caffeine can produce negative effects, including dehydration and shakiness.
From a skincare perspective, caffeine works to “perk up” the skin and stimulate circulation. Caffeine’s ability to constrict small blood vessels and reduce inflammation is an asset in many different creams designed to minimize dark circles and sagging under the eyes. Due to its high antioxidant content, caffeine also works to ward off free radical damage and environmental aggressors that cause aging, like UVA/UVB, ozone, and pollution. To top it all off, caffeinated body scrubs fight cellulite, too. Caffeine stimulates dilation while the scrubbing motion increases circulation, plumping up the skin and making cellulite look less obvious.
Are there any downsides?
Unfortunately, the wonderful effects of skin products containing caffeine are not permanent and can disappear when you discontinue using them. Eye creams containing caffeine may provide some benefits, but cannot alter genetics. Sometimes, when coffee berry extracts are used as antioxidants, they can cause breakouts as well.
Something else to bare in mind: use your caffeinated products during the day. Why? As mentioned before, caffeine is an antioxidant and benefits the body most during the day. Also, lots of caffeine in an eye cream or moisturizer worn overnight could result in long-term dehydration of the skin.