Spirulina in Pregnancy: Safety, Benefits and Side Effects

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Striking and vibrant with its trademark green and blue colors, spirulina is packed full of both micro and macronutrients.

While a concentrated nutrition powerhouse sounds great, is spirulina beneficial or safe during pregnancy?

Whether powder, pill, or tablet form, spirulina is generally recognized as safe, including during pregnancy. Selecting foods and products that are certified as quality by a third-party company is the best way to keep both you and baby safe.

While spirulina is generally safe, its status as a marine-grown supplement leads to some concerns, especially for pregnant women.

I’ll break down the benefits of spirulina, what to watch out for, and provide some brand guidance.

Is It Safe to Take Spirulina During Pregnancy?

Spirulina is a green-blue algae, usually found in foods as a powder or alternatively taken as a pill or tablet supplement.

Due to spirulina’s deep green or blue pigmentation, foods made with spirulina are often tinged with a similar green-ish blue hue. Those bright-blue smoothies? Their color is all thanks to spirulina!

Just as with other marine-derived products, contamination with heavy metals is of concern when it comes to spirulina.

Which metals are these? Nickel, zinc, magnesium, mercury, manganese, and platinum are the 6 metals typically considered as the “heavy metals” where toxicity is a concern.

Out of 25 spirulina supplements tested in 2013, none of them contained toxic levels of heavy metals (source: Saudi Journal of Biological Sciences).

In fact, all of the spirulina tested was well below the levels currently deemed as safe (source: Toxicology Reports).

spirulina pills and powder

Whether in powder, pill, or tablet form, spirulina is still considered a dietary supplement, which is not regulated by the Food and Drug Administration (FDA).

Some supplements are tested by third-party companies to ensure the spirulina is safe, of good quality, and pure.

Many of these certified products are also tested to ensure heavy metals are not present at toxic levels. A few examples are:

  • Elken (Good Manufacturing Practices certified)
  • NOW (Good Manufacturing Practices certified)
  • Nutrex Pure Hawaiian (Good Manufacturing Practices certified)

Spirulina may interact with some medications, so if you’re taking any prescriptions it is best to discuss any supplements with your medical provider before starting (source: Mount Sinai).

Spirulina is also available in various types, such as “green” and “blue.”

Blue spirulina is sometimes also referred to as “blue majik.” The two types are based on the processing of the spirulina.

The difference? Green spirulina is made from the entire algae whereas the blue pigment is isolated in blue spirulina. Two colors, but the same organism of origin.

Because the two types are made from the same blue-green algae their nutrition and safety remain the same as well (source: Doug Cook, RD).

Overall, spirulina is safe to incorporate into your diet, even while pregnant and is labeled as “generally recognized as safe” by the FDA. (source: Mount Sinai, Evidence-based Complementary and Alternative Medicine).

To ensure safety, it is best to only use dietary supplements from reputable companies and those that undergo third-party quality testing.

The Benefits of Spirulina For Pregnant Women

Packed full of nutrition, spirulina is made of up to 70% protein and is a complete protein source.

This means it contains all 9 of the essential amino acids (Sources: Evidence-based Complementary and Alternative Medicine, HealthLine).

Not only is spirulina a rich protein source, but the algae also contains a good amount of vitamins B1 and B2, as well as copper and iron (Source: NutritionData).

Iron is especially important during pregnancy, as it is needed for making more blood to help support a growing baby (source: UT Southwestern Medical Center).

Tip: If you know that you’re low on iron, or want to prevent deficiency, you might want to read our guide to 25 top Iron-rich foods to eat during pregnancy.

For mothers-to-be experiencing chronic fatigue, there is some evidence to show that spirulina increases lactobacillus, a healthy gut bacteria.

The lactobacillus then goes on to produce vitamin B6, which is critical for energy (sources: Evidence-based Complementary and Alternative Medicine, Frontiers in Nutrition).

Spirulina’s high nutrient content has led to its designation of “superfood.” While gram-for-gram spirulina provides great nutrition, the algae is concentrated and not the most budget-friendly way to get your daily vitamins and minerals in.

Other “greens,” such as kale, spinach, collards, and even broccoli, contain similar nutrients, though the serving size required to match spirulina’s more concentrated nutrition is larger.

If you do choose to incorporate spirulina into your routine, the easiest (and arguably the most popular) way is to blend a tablespoon or so into a smoothie.

Other ways to use spirulina include mixed into energy bites or stirred into a glass of juice (source: Bon Appetit).

spirulina powder

What Are The Side Effects of Taking Spirulina When Pregnant?

Spirulina has been shown to increase the time it takes blood to clot (Source: Biochimica et Biophysica Acta).

This means, if you accidentally cut your finger in the kitchen, it would take longer for the cut to stop bleeding.

For women who take a blood thinner, or anticoagulant, as directed by the medical provider, also taking spirulina may lead to excessive bleeding (source: Medline).

If you take any prescription medications, including blood thinners, always discuss supplements and herbs with your medical provider before starting.

Since spirulina is a blue-green algae, it is subject to being contaminated with harmful bacteria from the water it is harvested from.

The safest option, whether pregnant or not, is to choose a product that has been tested for safety (source: Medline).

As I mentioned above, taking a spirulina supplement that has not been certified by a third-party testing company for purity may pose a risk for heavy metal toxicity.

To avoid this potential side-effect, choose a supplement that has a quality certification and has been tested to ensure safe levels of any metals.

During pregnancy, healthy women who are not on any prescription medications, spirulina presents no significant side effects.

But to keep safe and avoid the effects of any potential contamination, only choose spirulina products from trustworthy companies.

green smoothie with spirulina and fresh raspberries

Can Spirulina Help with Infertility or Conception?

There is a great deal of confusing information out about ways to increase fertility and so it’s no surprise that many herbs and supplements are reported to have fertility-boosting effects. Spirulina is touted as one such supplement.

As women age, conceiving a child proves to be more difficult, in part due to an increase in oxidation.

There is some evidence that spirulina’s antioxidant effects increase the chances of conception, especially later in life (sources: Oncotarget, Pakistan Journal of Biological Sciences).

These studies were, however, done in animal models which doesn’t necessarily mean the same fertility-boosting effects will occur in humans.

Currently, there is no research to show that spirulina does increase the chances of conception in (human) women.

While spirulina won’t necessarily increase your chances of becoming a mother, it does pack a nutritious punch.

A good source of protein, B vitamins, copper, and iron, the nutrients in spirulina can help support a healthy pregnancy.

Being algae, spirulina has a risk of contamination with other harmful water bacteria and heavy metals, though studies show these metals are within safe levels in spirulina supplements.

As with all supplements, choosing a product tested for quality by a third-party company is important to ensure safety.


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