16 Benefits Of Adding Sea Kelp To Your Beauty Routine

Sea kelp is a type of brown algal seaweed. Although true kelp has a specific classification in the family Laminariaceae or giant kelp (per the University of Rochester), we often see seaweed of this kind fall under the broader class of Phaeophyceae, also known as brown algae. As a food and cosmetic ingredient, it's incredibly versatile and may already be in many products that you are familiar with or have in your beauty collection.

For instance, you can find it as an emulsifier, typically in the form of alginates that join ingredients that don't usually mix, like water and oil. It's also a thickener and stabilizer for many products, helping you get the kind of smooth consistency you'd expect from your moisturizers or creams. It has many additional properties which makes it particularly useful as the base or as an additive for cosmetics.

It's also a great source of nutritional vitamins and minerals, and in some countries is considered a dietary staple. It's more common for people in the West to use it in supplements because it's loaded with antioxidants, which may potentially help with heart, gut, and overall metabolic health, according to Healthline. Here, we'll be looking more specifically at what sea kelp can do in your beauty routine. Spoiler: It's a lot.

The efficacy of the skin's barrier is related to water loss. Although our skin is constantly exchanging water, when we're losing more water than the barrier needs to function optimally, this can be detrimental to skin health. According to dermatologist Dr. Dray, when our skin barrier is damaged, we increase the risk of infections, irritation, inflammation, and a multitude of other skin issues.

Macroalgae (or seaweed as you might know them) such as sea kelp have a variety of biological compounds, which can vary substantially because of the whopping 1,800 different species found in the brown algae group alone (per American Scientist). And among these are those that can help protect against transdermal water loss, ultimately promoting moisture retention.

For instance, research in a 2019 journal of Natural Products and Bioprospecting shows that certain brown algae stimulate skin to make hyaluronic acid, a type of complex carbohydrate that can help bind moisture to the skin and therefore reduce water loss. In addition, because it contains alginates (found in the walls of sea kelp) which can draw in and retain water, it can be doubly effective in aiding with moisture retention and preventing loss.

A 2019 research in the Journal of Marine Drugs explains that since seaweeds are often exposed to extreme sun throughout their life, they have developed various processes which give them a unique set of protections from damage. One of these is a high antioxidant content which helps to mitigate the effects of sun damage, and another is phlorotannins, a unique compound that has photoprotective abilities, meaning it can filter UV.

Another notable compound found in the study is a molecule called fucoxanthin (a pigment that gives the seaweed color). This inhibits the enzyme tyrosinase, which is the main catalyst for hyperpigmentation or excess melanin, one of the results of sun damage.

And finally, the third significant means of sun damage mitigation that brown algae offer is wound healing. In a 2022 study in the Journal of Algal Research on fermented sea kelp, it noted that fucoidan (another type of complex carb found in the cell wall) could promote wound healing. Researchers observed that it helped to stimulate the movement of skin repair cells to wounds, aiding in regenerating the top layer of skin.

Although skin naturally undergoes cell turnover, the addition of exfoliating products can aid this process in clearing debris and uncovering fresh skin below. However, chemical and physical exfoliants can often be quite harsh and irritating to some skin types. For instance, people with sensitive skin generally have a lower tolerance to cosmetic products, and the body can trigger an immune system response in the form of inflammation, redness, and rashes, according to DermNet.

This is where algae-based (specifically brown seaweeds) products can aid in removing dead skin cells without irritation, while simultaneously maintaining moisture. When sea kelp is added to exfoliants, research in 2019 (per the International Journal of Biological Macromolecules) shows that its components help to decrease sebum (i.e., oiliness), increase skin hydration, and retain water better than synthetic ingredients. Moreover, when compared to the synthetic variety, the algae-based exfoliator also caused less redness and irritation.

This may be because the alginates we find in sea kelp appear to be very compatible with the skin (when compared to other products). For instance, reviews on their properties highlight that they have no toxic effects on cells, not even the eyes — so they're unlikely to cause irritation even in sensitive skin (per the 2021 book "Alginates – A Seaweed Product").

Sea kelp contains fucoidans, a type of molecule with a carbohydrate structure or polysaccharide that has a number of therapeutic properties, including antioxidant, anti-tumor, and anti-coagulant (preventing blood clots), per a 2019 review in the Journal of Marine Drugs. But more recently, research has been looking into how this algae extract can assist with hair growth.

There are many factors that affect hair growth, but research in 2014 suggests one of the main elements is how well the body is able to make a certain type of protein called growth factor hormones (in the Journal Experimental Dermatology). For instance, in cases such as alopecia, where the body mistakenly attacks hair follicles and causes them to fall out, we see that individuals are often low in these proteins, suggesting that their presence is important in how hair grows.

Further, a 2022 article from the Journal of the Taiwan Institute of Chemical Engineers explains that fucoidans work because they activate the part of our genes responsible for creating these growth factor proteins, which in turn can stimulate follicle development and hair growth.

Probably what sea kelp is most famous for is its role in mitigating photoaging, i.e., when the sun prematurely ages the skin. Sea kelp does this by combating free radicals or oxidants. These oxygen molecules generated by UV are responsible for triggering photoaging and attacking the skin's cells, as well as causing cellular damage and a loss of structural integrity — two things which are the essence of wrinkle and fine line formation (per the Comprehensive Series in Photosciences, volume 3).

According to 2021 research in the Journal of Marine Drugs, sea kelp's fucoidan can act as an antioxidant, which means it breaks down destructive oxidants into more stable products. This reduces cellular damage while at the same time aids in restoring the skin's barrier. Coupled with another compound that brown algae species have — mycosporine-like amino acids (MAAs), molecules that form the building blocks of proteins — they can help to synthesize structural proteins like collagen, reinforcing the skin's structure to prevent wrinkle formation.

Inflammation is the immune system's response to damage or irritants. During inflammation, certain chemicals and cells act as mediators that make the blood vessels widen so that white blood cells can attack foreign entities, but in doing so, they actually trigger our pain response. And together, this can cause discomfort, swelling, and fever (per the National Institutes of Health).

Anti-inflammatories (like aspirin and ibuprofen) usually have the ability to prevent these inflammatory mediators — specifically, an enzyme called cyclooxygenase (or COX), which stops the body from inducing the processes involved in an inflammatory response, according to WebMD. But what's interesting is that sea kelp also have this effect, giving them anti-inflammatory properties.

As 2021 research in the Journal of Natural Product Communications explains, the phlorotannins compounds (an astringent chemical in the sea kelp's cell wall) inhibit COX and other enzymes that play a role in the inflammatory response. In addition, they suppress the immune system chemical histamine, which plays a role in allergies.

We've already talked a little about how effective sea kelp is as an antioxidant. Specifically, they contain phenolic compounds, which are one of many types of antioxidants capable of fighting oxidants. But according to Healthline, oxidation isn't always a bad thing. In fact, our body naturally produces these oxidants when it needs to fight infections.

The problem is when the balance of antioxidants and oxidants shifts into something called oxidative stress, i.e., there are more oxidants than we need, and this can play a role in skin issues such as pigmentary disorders, barrier loss, and uneven skin tone, per a 2021 article in the International Journal of Cosmetic Science. To combat this, Professor of Pathology Angelo Azzi at Tufts University explains that antioxidants — like phenolic compounds — work through a scavenging process.

Typically, oxidants or oxygen species steal negatively charged particles from cells, which impair how they function, whereas antioxidants do the reverse — they give the oxidants a negative charge, so they no longer take this charge from the cells that need them. And through this mechanism, research demonstrates that sea kelp can help to stop the diseases associated with oxidative stress, per a 2023 article in the Journal of Applied Phycology.

In cellulite, fatty tissue pockets poke through the underlying skin, which creates the dimpled appearance that so many of us hate. While the causes behind this aren't fully known, there are a few factors that can affect the severity of its appearance. According to research published in 2005 in the Journal of Cosmetic and Laser Therapy, changes to the underlying skin structure, namely the collagen bands or fibers that join the upper levels of skin to blood vessels, suggest that collagen loss plays a role. Another factor is how well the body metabolizes fat buildup, with researchers noting that poor circulation of fluids can play a role in tissue accumulation.

However, sea kelp can target these two aspects in several ways. First, since they aid in collagen synthesis, they may be able to restore the collagen malfunction involved in cellulite. Second, studies highlight they can help our bodies to metabolize or break down fatty tissue better. They also have the ability to stimulate blood circulation, which may help to stop the buildup of fatty tissues, according to Cosmetics Journal in 2018.

Similar to UV radiation, research highlights that exposure to environmental pollutants (such as nitrous oxides and PAHs from engine combustion) has an oxidizing effect on the skin. This has a cascading effect, breaking down the skin's barrier. As the skin tries to tackle oxidants, it uses up its antioxidant reserves to try and fight, but this ultimately exhausts its antioxidants and also triggers inflammation. This degrades the skin's connective tissues like collagen, per a 2017 article in the Indian Journal of Dermatology, Venerology, and Leprology.

Although collagen is abundant in the body, production can drop for a variety of reasons, environmental exposure being one of them. And since collagen plays such a key role in the skin's structure, its eventual depletion leads to wrinkling and loss of elasticity overall, according to Harvard School of Public Health.

According to 2023 research in the Journal of Marine Drugs, algae can help to mitigate some of this damage. It assists in restoring the skin's barrier by improving moisture retention, as the antioxidants help to tackle the oxidation. In addition, it also inhibits the enzymes that break down connective tissues, which help fight the structural damage pollution causes.

Acne is caused by the build-up of bacteria that thrive under certain conditions. While these bacteria aren't necessarily a problem on their own, when they're combined with excess sebum (the skin's natural oils) and dead skin cells, they start to dominate the other bacteria on our skin. They then produce enzymes that break down key parts of the skin's barrier, like proteins, lipids, and other components of the dermis, which exacerbates inflammation, according to DermNet.

Sea kelp has several compounds which can act as antimicrobial agents, such as phlorotannins, to help stop the spread of these bacteria. A 2021 article in Critical Reviews in Food Science and Nutrition Journal explains they prevent the bacteria from getting energy and binding themselves to the bacterial protein, eventually killing them. It also may be useful for skin conditions related to fungi, such as atopic dermatitis, dandruff, and steroid acne, which is caused by the fungus malassezia, per DermNet. The phlorotannins in the sea kelp have antifungal activity, which kills or stops the growth of these fungi.

Brittle or damaged nails may be associated with deficiencies in various nutrients, according to Healthline. For instance, iron deficiencies can cause splitting; calcium deficiency can make nails weak; and white spots can be a sign of low zinc. There are also components like thyroid issues that can cause discoloration or brittleness, which the mineral selenium may help to mediate.

Sea kelp is a rich repository of such minerals. For example, a 2020 article in Critical Reviews in Food Science and Nutrition Journal has found such brown algae species are high in selenium, calcium, potassium, and iodine, as well as quantities of iron, zinc, magnesium, and phosphorus.

It's also been marked as an antifungal agent, which can keep harmful nail infections at bay. For instance, according to studies published in 2019 in the Journal of Oceanology and Limnology, they're particularly good at tackling dermatophyte fungi, which can damage nail strength by feeding on keratin.

Fucoidans, a type of (polysaccharides) complex carbohydrate, can not only help with hair growth, they can also be helpful in maintaining the gloss and texture of hair. A 2009 article in Kosmetische Praxis explains that polysaccharides can act as a film on the hair and skin barrier, which allows these barriers time to recover from external damage and retain moisture.

Another factor in the overall appearance of hair is keratin. Examinations of hair anatomy show that this is the protein that makes up the main structure of our hair, most of which sits in the cortex, the middle layer of the hair. And it is this layer of keratin that gives the hair its strength and elasticity, so its loss or degradation can make the hair brittle and weak, per a 2017 article in the Journal of Materials Science and Engineering.

This is where the fucoidans of sea kelp can help, as a 2019 study highlights that it increases keratin synthesis by activating the genes involved in promoting their production, per Journal of Marine Drugs. And in doing so, this can enhance the smooth, shiny quality of hair as a whole.

Dark circles are a specific type of hyperpigmentation that occurs under the eyes. According to Medical News Today, some causes of undereye circles include anemia, lack of sleep, thinning skin, frequent rubbing in the area, smoking, eye treatments, and allergies. Sun exposure and certain nutritional deficiencies may be other causes. Because some of the causes are inevitable, such as aging or ethnicity (non-white people have a higher tendency to have dark undereye circles), this is a condition that's often difficult to treat, per Healthline.

This is where sea kelp can be helpful. Research in the Journal of Marine Drugs in 2018 notes that a combination of the compounds we find in brown algae species can target many different causes of dark circles at once. For instance, they help to inhibit melanin synthesis, which causes pigmentation, or induce collagen production, as they are filled with minerals that can help combat nutritional deficiencies.

Gum disease is caused by a build-up of plaque. This is the film of bacteria we get on the teeth combined with our salvia and food particles. As this plaque builds up, the associated bacteria feed on the sugars on our teeth and produce a type of acid that attacks enamel, causing cavities, tooth decay, and gum inflammation (via WebMD).

To combat this, sea kelp can assist on several levels. Research in the Journal for Systematic Reviews in Pharmacy in 2020 describes that kelp's fucoidans have an antibacterial effect on the microorganisms responsible for cavity-causing diseases like gingivitis and those that play a role in plaque build-up and gum disease.

They also explain that sea kelp can help with the inflammation caused by these bacteria by modulating the immune system response. A 2014 study explains it's due to the presence of a toxin that the bacteria make called endotoxin, per Journal of Marine Drugs. The fucoidans help to balance our immune system's response to this by promoting anti-inflammatory signals to balance the inflammatory ones that the toxins create.

But the benefits of sea kelp fucoidans don't end there. They're also humectants, a type of substance that can seal in water, creating a barrier around dry or irritated skin. There are various types of humectants that can do this, one of the most common being hyaluronic acid, a type of complex carbohydrate, per WebMD.

Of course, as we know, sea kelp is naturally rich in this humectant, but research in the Journal of Clinical Medicine in 2015 explains that irritation can also be the result of the chemical histamine that the immune system makes. It stops the skin from making certain proteins, which impairs the skin barrier. And this can cause the itching and inflammation you get when your skin's irritated.

Sea kelp fucoidans can also be helpful because of their antipruritic (itch-relieving) effects. As a 2012 article in the Journal of Phytotherapy Research explains, this works because they reduce the presence of histamine and suppress the corresponding inflammatory response.

As the American Academy of Dermatology reports, when something's wrong with the body, it often appears on the skin. Therefore, if we focus on what's going on within, it can affect the results we get with our skin. To this end, sea kelp can be a great overall dietary addition to your beauty routine because it's rich in nutrients that help our body to function.

As we noted, it's been shown to play a role in the prevention of several diseases, such as thyroid dysfunction and diabetes, but it may also help in anemia or iron deficiency. But you should keep in mind that with any natural product, its quality depends on where it's harvested from. For instance, areas of polluted seawater can mean the sea kelp might absorb toxic elements like arsenic and lead. Thus it's important to choose your supplier carefully (via WebMD).

This aside, a daily helping of sea kelp has been shown in research to provide us with a good source of dietary fiber, lower the risk of heart disease, and potentially help in sustaining a healthy body weight by boosting our metabolism and reducing cholesterol (Journal of Marine Drugs, 2021).