Does Spirulina go bad?

In this article, we will answer the question “Does Spirulina go bad?”, how long does Spirulina last, how to store Spirulina, what is Spirulina, what are the side effects of Spirulina, and how to avoid the side effects.

Does Spirulina go bad?

Yes, Spirulina goes bad. Fresh Spirulina goes bad like fresh vegetables. It withers, becomes discolored, or even becomes moldy if kept under poor storage conditions. 

Spirulina powder is no different. It can go bad if moisture gets to it. Moisture results in the formation of mold. Moldy Spirulina should be discarded right away as it can lead to food poisoning upon ingestion.

How long does Spirulina last?

The shelf-life depends on whether the spirulina is fresh or in powder form. The fresh stuff, with a higher water activity, naturally has a shorter shelf-life.

An unopened package of Spirulina powder lasts about 2 years if stored correctly. Once opened, it should be kept no longer than 3 months. Fresh Spirulina, stored in the fridge continuously after harvest, lasts about 21 days. Do not be surprised if it goes bad before 21 days.

How to store spirulina?

Fresh spirulina should be kept in an air-tight container in the fridge. Spirulina in powder form can be kept in a cool, dark, and dry place, away from direct or indirect sources of heat. 

The pantry or a kitchen cabinet are good places for storing Spirulina. Moisture and heat are the worst enemies of powdered Spirulina. If you opt for the kitchen cabinet, make sure the heat from the stovetop does not get to Spirulina.

What is Spirulina? 

Spirulina is a food-grade blue-green alga that grows naturally in freshwater and saltwater. Commercially produced spirulina is a key ingredient in some food items and supplements.

It will not be wrong to call spirulina a superfood since it is packed with protein (about 60% by dry weight), vitamins, and minerals. Not only this, it contains a considerable portion of healthy polyunsaturated fats.

Spirulina is possess excellent antibacterial, and anti-inflammatory properties. This is attributed to the antioxidants, called  C-phycocyanin and beta carotene, present in Spirulina. Last but not the least, Spirulina strengthens your immune system and improves your blood cholesterol profile.

What are the side effects of Spirulina?

Potential contamination with toxins 

Wild spirulina grows in water bodies that are frequently contaminated with heavy metals, bacteria, or microcystins. The production of Microcystins is a part of the defense mechanism of Spirulina against predators. Ingestion of microcystins above the threshold level can be toxic.

The toxic effect of microcystin is prominent on the liver. Scientists have been finding ways to purify Spirulina of these toxins or produce toxin-free Spirulina in the lab.

May worsen the autoimmune conditions 

Although Spirulina strengthens your immunity, the effects of Spirulina can backfire if you have an autoimmune disorder such as lupus, multiple sclerosis, and rheumatoid arthritis.

In this special scenario, Spirulina strengthens the very threat, that is the immune system, against the body cells. This results in weak muscles and damaged skin. Steer clear of Spirulina and other algae supplements if you have an autoimmune disorder.

May interfere with blood clotting 

Spirulina acts as a blood thinner, which helps to prevent excessive bleeding after an injury. The effects of spirulina on other blood-thinning medications are being investigated. Safe to say, you should stay away from Spirulina if you have a bleeding disorder or are a user of blood thinners.

Other downsides 

You may be allergic to Spirulina. You must consume spirulina to find out. But the allergic reaction can result in death Therefore, avoid taking Spirulina especially if you already have an allergy.

A compound called phenylalanine present in Spirulina is dangerous for those with phenylketonuria (PKU). So, stay away from Spirulina if you have been diagnosed with PKU. Some people may experience nausea, insomnia, and headaches when exposed to Spirulina.

How to avoid the side effects of Spirulina?

Always consult a doctor before you decide to incorporate Spirulina into your diet. The brands that you buy your spirulina from should be attested by Pharmacopeia (USP), ConsumerLab, or NSF International. This will ensure that you are not unknowingly ingesting microcystins or toxins.

Even then you can not be 100% sure that the Spirulina you are consuming is safe. This is due to the poor implementation of laws and regulations on dietary supplements.


In this article, we answered the question “Does Spirulina go bad?”, how long does Spirulina last, how to store Spirulina, what is Spirulina, what are the side effects of Spirulina, and how to avoid the side effects.

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