Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 12/27/2021
Some vitamins get all the attention when it comes to anti-aging skincare: Scan the beauty aisle and you’re bound to see products touting the benefits of vitamin C (antioxidant!), vitamin A (reduces wrinkles!) and let’s not ignore vitamin E (brightens under-eye circles!).
While these drugstore darlings have earned their place on the shelves, there may be a new rising star: vitamin K.
Your mom didn’t make you eat your vegetables because she liked bossing you around. (Let’s at least give her the benefit of the doubt here, m’kay?)
All those green leafy veggies like kale, spinach and brussels sprouts are actually packed with vitamin K (otherwise known as Phylloquinone).
It’s also found in fruits like figs and blueberries, as well as meat, cheese, eggs and soybeans.
Another form of vitamin K is through naturally-occuring bacteria in the gut. This type of vitamin K is known as menaquinones.
The body needs vitamin K to stay healthy: It’s an essential vitamin, and an important factor in blood clotting and bone health.
For a long time, vitamin K was only administered orally, but it has since been discovered that topical application of Vitamin K — for example, via cosmetics — may accelerate the blood coagulation process and make dilated blood vessels less visible.
There is also some evidence that vitamin K may contain anti-inflammatory properties that could help with the wound-healing process. (It’s important to note that more research is needed to determine just how effective vitamin K might be when it comes to healing. But it’s still pretty cool, nonetheless.)
That’s a good question, and one that is still being researched. While the anti-aging benefits of topical vitamins C, A and E have been known for quite a while, vitamin K is still a relative newcomer to the skincare scene.
However, studies have shown that topical application of vitamin K can reduce dark circles under eyes, aid in wound healing (as mentioned above), and decrease redness caused from capillary skin problems — like transient flushing and lesions.
As we age, the skin under our eyes loses elasticity and begins to sag.
Additionally, some people have naturally thin skin in their lower lids, resulting in pigment and blood vessels showing through the delicate skin. This results in the appearance of dark under-eye circles.
So what effect does vitamin K have on brightening dark circles? To be honest, there is not a ton of research available, however the reasoning behind using vitamin K to reduce the appearance of under-eye circles makes sense: Vitamin K is known to improve circulation and increase blood coagulation and has been used to help vascular conditions. And, dark under-eye circles may be considered a vascular condition.
In one study, 30 subjects with dark under-eye circles applied an eye cream with a formulation of 1% vitamin K.
Two subjects did not complete the study, but 26 out of the 28 remaining subjects said they observed a significant improvement. (The cream used in the study also included retinol.)
Another study tested the efficacy of an anti-wrinkle and dark-circle pad consisting of 3% caffeine and 1% vitamin K in Emu Oil.
While only 11 subjects were tested, the results showed that after four weeks, wrinkles were reduced, dark circles were lessened, and the appearance and elasticity of the skin improved.
It is thought that the formulation of vitamin K in the pad helped strengthen the capillary walls, reducing the visibility of the blood vessels in the thin under-eye skin, and ultimately reducing the appearance of dark circles.
As mentioned above, vitamin K is thought to help accelerate wound healing. In a randomized, double-blind study of 63 patients with wounds (54 completed the study), patients treated with topical vitamin K showed more improvements in the healing of their wounds.
The study showed that vitamin K can be used as a supplemental treatment for wounds.
The healing effects of vitamin K may be due to its relation to blood coagulation. Another theory is that Vitamin K may be an antioxidant, which helps heal wounds by decreasing reactive oxygen species (ROS). However, further studies need to be conducted for confirmation.
Another benefit of vitamin K is its ability to decrease redness.
Capillary skin problems can cause redness around the nose, cheeks and chin. The exact cause of this is mostly unknown, but the redness may be triggered by environmental and lifestyle factors that affect the vasomotor system.
A study tested whether topical vitamin K would effectively reduce redness in skin with vascular problems.
The results confirmed that vitamin K improved skin tone. Additionally, skin elasticity and hydration also improved.
A quick recap on all the awesome beneficial effects we now know about vitamin K:
We get most of our vitamin K intake from the foods we eat, and it helps our blood clot, our bones stay healthy — and may even have anti-inflammatory properties.
While we know that vitamin K is necessary for a healthy body, there are also studies showing vitamin K is good for our skin, too, and it is now found in some skincare products.
Because of its ability to help blood coagulate — not to mention the possibility that it’s also an antioxidant, when applied topically vitamin K may reduce the appearance of under-eye dark circles, redness and also possibly speed wound healing.
There’s still much to learn about vitamin K’s benefits, but so far this mighty vitamin is a valid up-and-comer and a good option to keep in your skincare arsenal. Call it ‘K,’ for keeper.