Thanks to the ever-expanding beauty industry, it’s not uncommon to hear about new trends, new ingredients, and products that are just begging to be dubbed “The Next Big Thing.” While we’re all searching for the next beauty routine game-changer, it is also good to be a skeptic, breaking down the how and why of it all. One of the most recent buzzy ingredients to hit shelves is spirulina.

First introduced in nutritional supplements (and in smoothie and juice bars), spirulina is a blue-green algae that boasts an impressive amount of nutrients, including protein, vitamins, minerals, carotenoids, and antioxidants. Now, we’re seeing the ingredient pop up in the haircare aisle. And if you can’t help but wonder what exactly spirulina does for hair, then this article is for you. We’ve tapped expert dermatologist Dendy Engleman, MD, as well as board-certified trichologist Kari Williams, for their thoughts on spirulina.

What Is Spirulina?

Spirulina is a microalgae superfood that is packed with nutrients like protein, iron, amino acids, fatty acids, and various vitamins. It contains a wide range of nutrients, including zinc, B vitamins, vitamin E, various antioxidants, minerals, fatty acids, amino acids, and chlorophyll. It is also full of antioxidants and high in protein. Spirulina can be found in hair growth supplements and powder forms, as well as in skin and hair care products.

Does Spirulina Help With Hair Growth?

Spirulina’s chief benefit for hair is hair growth. It contains 70% protein, fatty acids, and iron, all nutrients that the body needs to promote hair growth. In fact, recent studies show that spirulina can help those affected by conditions with excessive hair loss as a symptom (such as alopecia) stimulate hair regrowth.

Benefits of Spirulina for Hair

Since it’s such a potent source of nutrients, spirulina provides numerous benefits for not only the body but also hair. While the main benefit that spirulina has for hair is promoting growth, there are numerous others, including:

• Treats hair loss/facilitates hair renewal: Oxidative stress, or an imbalance between free radicals and antioxidants in the body, can lead to aging. Spirulina is full of antioxidants, which help counteract oxidative stress and keep blood sugar levels regular, which can help those experiencing hair loss.
• Fights dandruff: Due to its antimicrobial properties and zinc content, spirulina is great at fighting dandruff.
• Moisturizes and hydrates the scalp: The hygroscopic molecules in microalgae take water particles from the environment and deliver them to the scalp and skin.
• Soothes the scalp: Spirulina’s sugars, proteins, and amino acids are excellent for soothing and rebalancing the scalp and helping its barrier function work properly.
• Controls sebum production: The proteins, polysaccharides, and fibers in spirulina are also natural polymers that can create a protective film on the scalp, leading to hydration, which can also help control sebum production.
• Slows down the appearance of gray/white hairs: Because of spirulina’s high content of iron, amino acids, as well as its pigments, it can help disguise those pesky grays.
• Supports glossy, shiny hair: The antioxidant compounds of spirulina can help make your hair more glossy, stronger, and shinier.

Hair Type Considerations

“Spirulina is generally recognized as a safe ingredient—barring rare allergies or individual adverse reactions—so I would not caution any specific hair or skin type against taking spirulina,” says Engelman. “This ingredient is great for anyone who wants to promote healthy hair growth and get a dose of antioxidants and vitamins.”  Spirulina is not recommended for someone with existing allergies, especially to seafood, seaweed, or other sea vegetables. Those with low-porosity hair might want to avoid spirulina—the protein might be a little too much for your hair.

How to Use Spirulina for Hair

Spirulina supplements or powder can benefit hair, and it’s becoming incredibly popular in hair products. Engelman loves Prose because it offers haircare products customized for individual hair and scalp needs. “The Pre-Shampoo Scalp Mask and Custom Shampoo can be formulated with spirulina and are packed with other nourishing ingredients to strengthen, rebalance, and hydrate the hair and scalp,” she explains.

Williams also suggests adding spirulina to your shampoo and conditioner or into your favorite hair mask. “Allow the conditioner or mask to sit on the hair as you would during a normal haircare routine, and rinse completely,” Williams says. She also adds that it can be good for scalp massage: “Spirulina can also be blended into a hair oil and massaged into the hair and scalp.”

Potential Side Effects

Although spirulina is generally considered safe, like with any supplement, it is possible to experience side effects. According to researchers, if spirulina grows in bodies of water polluted with heavy metals, bacteria, or microcystins (a type of bacteria produced by blue algae to protect it against predators), it can become contaminated with toxins. Effects like cramping, bloating, gassiness, diarrhea, dizziness, and vomiting can occur. The best way to avoid the potential risks is by consulting a trusted doctor before taking any new supplements.

The Final Takeaway

Spirulina is a type of microalgae that is filled with nutrients like protein, iron, amino acids, fatty acids, and various vitamins. It can be found in food and supplements, as well as skin and haircare products. Spirulina can promote hair growth, as well as hair and scalp health. Spirulina is generally safe, but those with existing allergies to seafood, seaweed, or other sea vegetables and those with low-porosity hair should avoid the ingredient. Before taking any new supplements, speak with a trusted physician who can advise based on your medical history.