Spirulina is a dietary supplement derived from sea algae that is valued for its incredibly high vitamin, mineral, and protein content, as well as its powerful antioxidant effects.
Because of the “superpower” properties, it is found in many superfood green drinks.
It’s been studied for use in fighting cancer, allergies, high cholesterol, and for fighting inflammation. It’s even been used by NASA as a nutrient-rich source of sustenance for astronauts on space flights.
It creates energy from sunlight using photosynthesis, just like plants do, so it offers many of the same health benefits as leafy green vegetables.
Our researchers have evaluated and ranked the best spirulina supplements on the market, ranking them according to quality.
1. Viva Naturals Spirulina Powder
For those seeking a high dosage of spirulina, tablets aren’t going to cut it. The powder-based spirulina supplement from Viva Naturals is grown in the United States, and the powder is independently tested for purity.
Add to this the fact that you can calibrate your dosage as low or as high as you’d like, and you’ve got all the makings of a top pick.
2. Nested Naturals Super Algae
Nested Naturals packages spirulina alongside chlorella, another algae, for extra antioxidant and heavy metal scavenging properties.
This spirulina supplement is ideally suited for people looking to take advantage of the detoxifying abilities of spirulina and chlorella; thanks to their ability to bind with heavy metals like lead and mercury, this is a popular choice for detox regimens.
3. BulkSupplements Pure Spirulina
For massive spirulina doses, there’s no other way to go than BulkSupplements. With 1000 grams of spirulina per bag, and no ingredients aside from spirulina, if you take large doses of spirulina every day, this should be your choice.
Other spirulina supplements have a leg up when it comes to organic sourcing, so it’s not our top pick, but for bulk users it’s still a winner.
4. Pure Hawaiian Spirulina
Each tablet of this spirulina supplement contains half a gram of pure spirulina, derived from a special farm in Kona, Hawaii.
This promises better purity control than supplements sourced elsewhere, and the nutrient content of this spirulina is excellent. Silica is the only binder or filler in the capsule, and it’s made from vegetarian-friendly cellulose, making this a very solid choice.
5. Perfect Aquatic Greens
This powder-based spirulina and chlorella supplement is certified organic and provides a 50/50 mix of each, by weight.
The supplements are solid, but unfortunately the total dosage contained in a tub is barely half of what’s in many of the other powder-based spirulina supplements on the market. Still, for a powder-based algae supplement, this is the best choice if you want chlorella as well as spirulina.
6. Now Spirulina
Now Foods makes a pretty solid spirulina supplement whose sole ingredient is certified organic spirulina.
The manufacturer gets around the problem of a capsule for delivery by pressing the powder firmly into dry tablets that provide one gram of spirulina each. While it’d be nice if the source of the spirulina was disclosed, the fact that it’s organic is a good sign.
7. LuRoot Spirulina
LuRoot is pretty boilerplate when it comes to spirulina supplements: half a gram of spirulina, delivered in a vegetable cellulose capsule.
The low dosage and lack of sourcing information, or other perks like an organic certification, knock it downward in the rankings compared to the competition.
8. Nature Bound Spirulina
Nature Bound Spirulina is another fairly basic spirulina supplement that provides a lower dosage (half a gram per tablet) and uses high-pressure machining to press the powder into a tablet.
Without an organic source, or more details on purity, this spirulina supplement doesn’t really distinguish itself in a meaningful way from the competition.
9. Natural Nutraceuticals 100% Organic Spirulina
This supplement provides an American-sourced, certified organic spirulina supplement. Each tablet is a half-gram pressed powder, meaning there are no other ingredients aside from spirulina.
The downside is that the intense pressure from the tablet pressing process might slow or hamper the absorption of the spirulina, and it would be better if the dosage was higher.
10. Pure Healthland Super Spirulina
This capsule-based spirulina supplement has a fairly low dosage and isn’t stellar when it comes to providing info on the sourcing of the spirulina that goes into the supplement.
At only half a gram per capsule, it’s outclassed by many competitors.
Who should buy spirulina?
Spirulina contains powerful antioxidant agents and phytonutrients. These ingredients make it a good option for people who are looking to augment their intake of micronutrients with plant-based materials.
Moreover, the specific benefits of spirulina are useful for people looking to improve endurance performance, decrease the symptoms of seasonal allergies, and reduce their risk factors for heart disease.
In this sense, spirulina has a combination of short-term and long-term health benefits. Its ability to reduce cholesterol levels and improve blood pressure can be chalked up to its antioxidant content; many other supplements that contain strong antioxidants, such as resveratrol and astaxanthin, exert similar cardiovascular benefits.
The endurance benefits, and the ability to alleviate allergy symptoms, probably have more to do with specific biologically active compounds found in spirulina itself, as these are more distinct and unique properties.
Even if you aren’t looking for a specific biological mechanism of action for any particular health condition, spirulina is still a great addition to a healthy diet. It’s a core ingredient in many green superfood drinks, and is an easy addition to a protein shake for an added antioxidant boost.
How we ranked
When formulating our spirulina rankings, we put a premium on purity. We only included supplements that had spirulina as their primary ingredient. General green vegetable extracts and powders didn’t make the cut.
We also eliminated any liquid-based spirulina supplements, since the relatively fragile antioxidant compounds and micronutrients in spirulina will last longer when dried in a powder. Plus, this means there’s less of a need for preservatives to maintain the integrity of the other ingredients.
Speaking of preservatives, we dropped supplements from our list that used synthetic ingredients as preservatives, flavoring agents, binders, or fillers.
We made allowances for ingredients necessary to make capsules, but even so, our top-ranked capsule based product, Nested Naturals Super Algae, has only one ingredient other than spirulina, and it’s a plant-based compound that makes up the capsule.
When it came to the spirulina itself, we used slightly different criteria to evaluate powder versus capsule-based spirulina supplements.
With capsules, products with a higher per-capsule dosage scored higher than those with less spirulina per capsule. The same was true for the total amount of spirulina per bottle: we wanted our top-rated products to deliver the best value.
With powder-based products, we also had a strong preference for more spirulina per pouch or per tub, but we also factored in usability concerns.
Large plastic resealable bags can provide great value, but can be messy when you are working with a finely powdered substance like spirulina. For both powders and capsules, products whose purity and ingredients have been confirmed via independent, outside laboratory testing scored much higher than those which did not.
Spirulina has a very dense concentration of micronutrients. An organism that grows in fresh or salt water, spirulina contains such an assortment of beneficial substances; it may well be the most nutritious food on the planet.
Also known as blue-green algae, spirulina may seem an unlikely superfood since it’s technically a type of bacteria, but in the same manner as plants, it uses the process of photosynthesis to manufacture energy.
Aztecs knew the power of spirulina, and it has recently become the focus of attention as a potential source of nutrition for astronauts since it can be grown in space. (1)
It can be purchased in both powder and tablet form, and usual dosages range from 1 to 3 grams, but as much as 10 grams daily has been proven effective in studies exploring spirulina’s health effects.
One tablespoon of dried spirulina delivers 4 grams of protein with only 20 calories; it also provides respectable amounts of many vital nutrients. (2)
Here’s what you can expect from supplementing 7 grams of spirulina daily: 21% RDA for copper, 15% RDA for vitamin B2, 11% RDA for both iron and vitamin B1, 4% RDA for vitamin B3.
It also includes smaller amounts of potassium and magnesium, as well as other nutrients necessary for maintaining the human body
The protein in spirulina is considered comparable to that found in eggs, containing all the essential amino acids; the low amounts of fat will provide some omega-6 and omega-3 fatty acids in a ratio of 1.5 to 1.
Spirulina can reduce several risk factors for heart disease. Nearly 800,000 Americans died of heart disease in 2011, and it ranks as the number one cause of death worldwide. (5)
Several blood markers associated with heart disease can improve dramatically with the supplementation of spirulina.
Both LDL cholesterol (the bad kind) and blood triglyceride counts drop when spirulina is added to the diet, and HDL cholesterol levels go up, effectively reducing the chances of developing heart disease.
A study of test participants with high cholesterol who took a gram of spirulina daily found LDL cholesterol levels fell by just over 10%, while blood triglycerides decreased by more than 16%. (6)
Spirulina has been proven to decrease the oxidization of blood LDL lipoproteins in animals and humans (9, 10, 11). Lipid peroxidation, which is an indication of oxidative damage to the body’s fatty structures, can raise the risk of developing serious diseases.
A small study with 37 patients suffering from type 2 diabetes noted lower levels of oxidative damage as well as higher levels of antioxidants in the blood from the addition of 8 grams of spirulina daily. (12)
Another risk factor for heart disease is hypertension (high blood pressure); and spirulina may be useful in decreasing blood pressure through bumping up production of nitric oxide. This molecule acts in the signaling process that allows blood vessels to dilate and relax. (13)
While lower dosages aren’t effective, 4.5 grams of spirulina daily lowered readings in people who had normal blood pressure. (14)
Spirulina can reduce the damage caused by free radicals in the body. Besides dropping the risk of developing heart disease, the use of spirulina may also help prevent other serious health issues related to oxidative damage. (15)
The generous amounts of antioxidants found in spirulina can reduce the damage done by free radicals in the body; inflammatory responses are also positively impacted, which has beneficial effects on risk factors for chronic diseases. (16)
Phycocyannin is the main active ingredient in spirulina that acts as an antioxidant; it also imparts the distinctive blue-green color to the substance. (17)
Animal studies indicate spirulina can cut the chances of developing cancerous tumors, as well as inhibiting tumor growth. (18)
More human studies have been done with oral cancer than other types. When researchers tracked the response of patients with precancerous lesions in the mouth, results were impressive.
Nearly half the subjects taking a gram of spirulina daily for a year experienced complete regressions, while the control group rate (no treatment) was significantly lower at 7%. (19)
When spirulina treatment stopped, nearly 50% of the participants whose lesions had disappeared began to develop them again.
In another study, researchers compared the effects of spirulina with the pharmaceutical drug pentosyfillene in treating oral lesions such as those described above; a gram of spirulina a day resulted in greater improvements than using the drug. (20)
Spirulina can improve allergy symptoms. Spirulina has been tested for its effectiveness in several other areas, including the treatment of allergic rhinitis, or the inflammation of nasal passages.
This condition can be triggered by environmental conditions such as exposure to animal hair, pollens, or substances that can differ between individuals.
One study with more than a hundred subjects suffering from allergic rhinitis found taking 2 grams of spirulina daily eased symptoms, including nasal congestion and discharge, as well as itching and sneezing. (21)
Anemia may be improved by spirulina supplements. There are several different types of anemia, one of the most common types often affects elderly patients.
The lower level of red blood cells in the body characteristic of anemia can lead to general fatigue and overall weakness. (22)
When anemic patients supplemented with spirulina, red blood cell counts rose; their immune systems also grew stronger. (23)
Athletes may find taking spirulina improves performance through reducing oxidative damage in muscle tissue.
Spirulina can help improve endurance performance. Two separate studies indicated endurance was improved in subjects who included spirulina supplements, extending the time athletes were able to exert themselves before becoming fatigued. (24, 25)
Another study conducted with college athletes showed that muscle strength was significantly enhanced by adding spirulina, but endurance wasn’t affected.
Spirulina might help detoxify your body and regulate blood sugar. Spirulina also shows promise as a detoxification strategy for patients suffering from high concentrations of heavy metal in the body. When subjects with arsenic poisoning were give spirulina supplements, levels of arsenic dropped dramatically.
In one small human trial following 25 patients diagnosed with type 2 diabetes, results appeared promising; on a two-gram daily dose of spirulina, subjects experienced substantial drops in blood sugar. (29)
Spirulina supplementation might help maintain a healthy liver. One of the potential benefits of spirulina, which is a strong source of chlorophyll and other phytonutrients, is its ability to act as a heavy metal detox.
The molecular structure of the constituents of spirulina make it well-suited for scavenging heavy metals, such as lead or mercury, in your body. Some scientific research even supports the idea that it could help protect your body from damage after being exposed to heavy metals.
One study, published in the Journal of Health Science by researchers in Japan, used an animal model to test whether spirulina could protect mice against damage from mercury (30). The researchers had two groups of mice, one of which had a normal diet, and one of which had a normal diet augmented with spirulina.
Both groups were then exposed to small amounts of mercury. The researchers tracked biomarkers of damage to the liver in both groups, and found some evidence that the mice that were taking spirulina suffered less liver damage, presumably because the spirulina had scavenged some of the mercury in their body and thereby reduced the amount of damage to the liver.
While more research is needed to see if humans can also improve their liver health by taking spirulina, these results show some promise.
The safety of spirulina as a dietary supplement was reviewed in 2011 by United States Pharmacopeia, an organization which certifies the safety and purity of supplements and medications (31).
The report reviewed the safety record of spirulina, as well as the current state of any regulatory actions against spirulina supplement manufacturers. While the report noted a few case reports that had associated spirulina with side effects like liver dysfunction and allergic reaction, it also noted that these cases typically involved supplements with many different ingredients, only one of which was spirulina.
Moreover, evidence from animal studies discussed earlier suggests that spirulina might actually be protective of liver. Other animal research suggested that even tremendously high amounts of spirulina, consumed over a long period of time, are not harmful.
The United States Pharmacopeia report did note that a few unscrupulous manufacturers had been advertising levels of purity, and independent lab certifications of purity, that they did not actually have.
This resulted in legal action against these manufacturers, and changes in the marketing practices of these companies. As long as you stick with a top-rated spirulina brand, you shouldn’t have any problems with purity.
There’s still a lack of large, high-quality studies on spirulina in humans, so the dosages that have been used successfully range from about one to ten grams of raw spirulina powder per day.
As with other more experimental supplements with poorly characterized optimal dosages, it’s best to start with a lower dosage (maybe one or two grams), then stepping up the dosage gradually if you are not getting the results that you want.
Q: Can spirulina be harmful?
A: According to the latest safety reviews of spirulina, there is very little evidence that spirulina can be harmful. Studies in animals have found that it is exceptionally safe, even at very high doses.
A handful of case reports have described liver problems or allergic reactions in people taking supplements that include spirulina, but these almost inevitably involve supplements with many other herbal ingredients in addition to spirulina, making it very difficult to ascribe the cause to spirulina, especially considering the fact that animal research suggests that spirulina might actually protect your liver.
While the recommended dose is between one and ten grams, people often take up to 40 grams per day without any apparent issues. The strong safety profile of spirulina is one of its best selling points.
Q: How long does spirulina last once opened?
A: Like many antioxidants, spirulina has a shelf life that’s a bit shorter than other supplements. This is due to the fact that exposure to air, light, and oxygen rapidly degrades the very compounds in spirulina that make it beneficial.
Before you open a spirulina supplement, it will last for at least a year, but once it’s been unsealed, you should toss it if it’s been more than three months.
Exposure to light, heat, and oxygen will degrade spirulina faster, so you can preserve the quality of your spirulina supplement by keeping it in the refrigerator in an airtight and opaque container, where it will preserve its antioxidant properties for longer.
If you buy spirulina but don’t want to use it right away, you can even freeze it. Just make sure you don’t unfreeze and refreeze your spirulina supplement over and over, because moisture will quickly make its way into your spirulina supplement and degrade its quality.
Powder form spirulina will also degrade more quickly after being opened, since it has a much greater surface area that is exposed to the air.
Q: Why is spirulina called a superfood?
A: Spirulina is known as a superfood thanks to its incredibly dense concentration of phytonutrients: as you might guess from its dark green color (a property shared with other superfoods like kale, spinach, and broccoli), spirulina is packed with antioxidants, vitamins, and minerals.
This makes it an excellent supplement to combat inflammation and oxidative damage. In this context, its ability to reduce many of the risk factors for heart disease is not surprising.
Heart disease, along with other common chronic health conditions like type two diabetes, is linked to inflammation and oxidative damage. Thanks to its powder format and dense concentration of nutrients, spirulina is one of the most common ingredients in high-quality green superfood drinks.
Q: What is spirulina?
A: Spirulina is produced by cyanobacteria, which are a type of “blue green algae” which produce energy via photosynthesis. Technically, spirulina isn’t produced by algae; it’s more in line with a probiotic than anything else.
Still, because the cyanobacteria produce their energy using sunlight, they have many of the same nutrients (including chlorophyll) that you’d get in a green leafy vegetable like chard or kale, but in a much more densely concentrated form.
You won’t get 100% of the benefits of raw veggies, because the spirulina produced by cyanobacteria lacks much in the way of fiber (though this is also allows spirulina to have such densely concentrated nutrients).
Q: Where can you buy spirulina?
A: Spirulina is pretty easy to find at any health foods store, but if you want a top-rated supplement, you’ll probably want to shop online.
Spirulina is fairly popular, so there are a lot of products out there. However, you want one that has a high dosage and not much in the way of other ingredients.
Q: How should you eat spirulina?
A: If your spirulina comes in a capsule, it’s pretty easy to figure out how to take it. But if it’s powder-based, the story is a little different. Many people like to mix their spirulina powder into protein shakes and smoothies.
You can even add it to oatmeal or hot cereal if you don’t mind the taste. Since it’s powderized so finely, it usually mixes up fairly well in a liquid, but if you try mixing it with just plain water, you might need to put some extra effort into mixing up the solution, since it isn’t technically soluble in water.
Q: How much protein is in spirulina?
A: Spirulina is surprisingly high in protein for a green superfood; a seven-gram serving of spirulina powder has four grams of protein.
That means that spirulina is almost 60% protein by weight. Since the recommended dose of spirulina is between one and ten grams, it’s hard to get a significant contribution to your diet in terms of absolute protein content, but it does make it even easier to justify adding spirulina to a protein shake.
Q: Why is spirulina good for you?
A: Spirulina includes a dense mixture of antioxidants and micronutrients, making it a good way to augment your daily intake of phytonutrients.
Spirulina reduces a number of risk factors for heart disease, including blood cholesterol levels and blood pressure, so it’s great for your long-term well-being.
On top of that, spirulina appears to help alleviate allergies and could even improve endurance exercise performance, so it’s a very well-rounded supplement with a wide range of benefits.
Q: How can you make spirulina taste good?
A: The astringent and slightly sour taste of spirulina isn’t for everyone. It can taste just how it looks–green. To get around this, you can mix it in with a great-tasting protein powder, or include it in a smoothie with natural non-caloric sweeteners like stevia that can mask some of the harsher notes and flavors in spirulina.
Of course, not everyone dislikes the taste of spirulina; you’ll occasionally see it as an option for a flavor and nutrient shot at smoothie and juice bars, alongside green drink mainstays like wheatgrass and chlorella.
If you really can’t stand the taste of spirulina powder, you can always opt for a capsule-based supplement instead. That way, you won’t taste the powder at all.
We hear a lot about “superfoods” and how they can make positive contributions to health; while many contenders may not deserve the status, spirulina is truly a nutritional star.
It’s readily available and reasonably priced, making it simple and easy to add to your health program.
Spirulina is a water plant loaded with antioxidants, vitamins and minerals; it is effective in lowering cholesterol, preventing oxidative damage, discouraging the growth of cancerous lesions, and may prove to be helpful in managing a range of other health conditions.
For BodyNutrition‘s #1 spirulina recommendation, click here.