Spirulina is a microalga known for centuries for its nutritional value and positive health effects. The blue-green alga naturally grows in oceans and salty lakes in subtropical climates. Back in Aztec times, it would be harvested from Lake Texcoco in central Mexico and nowadays it’s still harvested from Lake Chad in west-central Africa.

What do spirulina supplements do?

You will generally find spirulina either as a powder or in capsules and flakes. Interestingly, spirulina is not only used as a supplement but also a color additive in gum, candy and other packaged foods. I used to add the powder to my morning protein shake, but the fishy, mushroomy taste made it taste so awful that I switched to capsules.

 

Many vegans use it as a protein and vitamin B12 source because it’s around 55-70% protein. If you take if for vitamin B12 reasons, keep in mind that studies suggest the vitamin is not absorbed well and you might lose quite a bit during digestion.

 

The reasons spirulina is often marketed as a general health supplement is because of its wide range of supposed benefits, including heart health, metabolism and high cholesterol. Unfortunately, because the research on spirulina is limited, the National Institutes of Health (NIH) concluded that there is not enough scientific evidence to determine if Spirulina is effective in treating any health conditions.

 

That said, there is evidence supporting its anti-inflammatory effects. Even though we still need further research to determine whether spirulina can fight off sickness, it has been shown to be pretty good at reducing symptoms of nasal allergies. Even low doses of spirulina taken daily were shown to improve the stuffy nose and sneezing often associated with allergies.

Studies that tested spirulina used all kind of doses, so it’s difficult to give you an ideal dose. A good starting point is to use 2 g of  spirulina daily for at least three months. This should give you enough time to see if it has a positive effect on your allergies.

There are no apparent side effects linked to higher spirulina intake, but doses exceeding 8 grams have not found any clear benefits so it’s really a waste of money.