One of Earth’s oldest natural skincare ingredients doesn’t grow on dry land, but instead thrives in its vast oceans. Seaweed comes in more than 10,000 varieties, and nearly every coastal culture has used it in one way or another. East Asians have long known the benefits of eating seaweed, but researchers now realize you can also absorb its healthy stock of vitamins and minerals through the skin.
“Your skin actually gets higher levels of nutrients when you apply seaweed directly,” says Diane Bernard, owner and founder of Seaflora Skincare and Outercoast Seaweeds, a British Columbia, Canada–based seaweed-harvesting company. Much like our skin cells, seaweed takes in whatever resides in its immediate surroundings, good and bad. From seawater, seaweed gains its rich cocktail of 13 vitamins and 60 trace minerals, a tonic unrivaled by any on-land botanical. But seawater in heavy shipping regions, such as those in China and parts of Europe or those with recent oil spills, can infuse the plants with higher levels of lead and mercury—not exactly the minerals you want in your sushi or on your body. So whether you plan to eat it or bathe in it, find out where the seaweed was harvested. The colder the water and the farther north the origin (think Canada and Ireland), the less polluted the seaweed will likely be. You might also look for seaweed that’s been sustainably harvested from ocean gardens.
Because seaweed can be a boon to depleted or imbalanced skin, it has become irresistible to the spa and beauty industry. “Virtually every highend skincare company uses some type of seaweed derivative in their product line,” says Valerie Gennari Cooksley, RN, author of Seaweed (Stewart, Tabori & Chang, 2007).
Luckily for our skin, this popularity has more to do with seaweed’s effectiveness than its trendy status. As Cooksley explains, positively charged ions in the epidermis attract seaweed’s negatively charged ions. Like a magnet, the skin pulls in the plant’s rich nutrients, eventually drawing them all the way into the bloodstream, where they help carry toxins away from the body and regulate tissue pH balance.
Despite their common source, all seaweeds are not created equal, and finding the right product or treatment can take some work. Cosmetic descriptions of seaweed-based ingredients can range from the general (seaweed extract) to the opaque (phytelene complex), but knowing the three main types of seaweed and their benefits can help you create your ideal ocean spa treatment.
Brown seaweed
A product that lists only the generic term seaweed as an ingredient generally uses a form of brown seaweed. Often collectively referred to as kelp, brown varieties detoxify the body with their potent iodine and mineral content and appear in body wraps or as simple additives to warm bath water. The Japanese use bladderwrack to dissolve fat deposits and remove excess water, making it a popular addition to cellulite creams. Pregnant women in Korea use alaria (or wakame) as a paste to prevent stretch marks.
Label lingo: alaria, alginic acid, bladderwrack, Fucus evanescens, kelp, kombu, Laminaria digitata, Macrocystis pyrifera, rockweed, wakame
Red marine algae
A high beta-carotene content gives these varieties their deep color. The reds contain the highest number of moisturizing properties among all three seaweed types. Lotions and creams often include Irish moss and its gel extracts as a binder (giving them a silky consistency) and also for their antiviral properties.
Label lingo: agar, carrageen, Chondrus crispus, dulse, iridaea, Irish moss, Palmaria palmate, rainbow seaweed, red chondrus palmaria, RMA (red marine algae)
Green seaweed
Although 1,200 types of green seaweed exist, you’ll probably only find sea lettuce in skincare products. The lightly textured lettuce stimulates collagen and elastin growth, and its astringent qualities tone and tighten pores.
Label lingo: sea lettuce, Ulva lactuca