Spirulina Side Effects Clarity: 3 to 5g Per Day To Remove Doubts

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Spirulina Side Effects: Separating Fact from Fiction

Spirulina powder is a popular supplement that many people use to enhance their healthy lifestyles. Made in Australia by Fresh Spirulina, this juicing ingredient is freeze-dried to preserve its raw, 100% natural, GMO-free, and plant-based protein content.

Spirulina is rich in antioxidants, iron levels, and beta-carotene, which can support various health benefits, including immune function, skin health, and exercise performance. However, some people may wonder if Spirulina has any side effects that could harm their health. In this article, we will explore the most common Spirulina side effects and whether they are safe for consumption.

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How much spirulina can you consume? What are spirulina’s side effects?

Spirulina can be purchased in tablets, capsules, powder, or fresh form while spirulina powder is the most commonly known way to consume spirulina.

To avoid spirulina side effects the recommended dose is 3 to 5 g distributed among the main meals (20gr per day in total, can be taken in one go as well).

Side effects

Rich in protein and fibre content

Some people may have any of the following spirulina side effects which are all result of your body not being used to eating food so rich in protein and fibre:

  • Thirst and constipation. After taking a large volume of spirulina it is recommended drink about half a litre or more of water a day to help your body absorb it.
  • A little fever is due to the body’s need to burn the extra protein.
  • *Slight dizziness, If this occurs, take less spirulina if the symptom does not improve stop taking spirulina and consult a qualified doctor or naturopath.
  • Stomach ache.
  • *Mild itching or rash on the skin.

*Note that ‘slight dizziness’ & ‘Mild itching’ could be from a spirulina product that is contaminated.

You should strive to acquire quality spirulina that has been grown in pure ecosystems since algae have an important capacity to absorb everything in the media in which it grows, especially heavy metals (more about the latter further down on this page).

Upset stomach and diarrhea

Some people may experience digestive issues, such as bloating, gas, cramps, and diarrhea when consuming Spirulina powder. However, these side effects are usually mild and temporary, and they may occur due to various reasons, such as the high protein content of Spirulina, individual sensitivity, or contamination of the product. Nothing dangerous.

To reduce the risk of digestive discomfort, it’s essential to choose a high-quality Spirulina powder that is lab tested for purity and safety, follow the recommended dosage, and avoid mixing it with acidic foods or beverages.

In some cases, the consumer is simply not used to the high levels of fiber causing the stomach to work “harder”. As soon as your stomach is used to the new levels of protein and fibre all the symptoms are likely to disappear.

Allergic reactions

Although Spirulina is generally considered safe for most people, some individuals may develop an allergic reaction to it, especially if they have a history of allergies to seafood, iodine, or other types of algae. (Note that Spirulina should not be taken as a source of Iodine).

Symptoms of an allergic reaction to Spirulina may include itching, rash, hives, swelling, breathing difficulties, and anaphylaxis in severe cases. If you experience any of these symptoms after taking Spirulina powder, stop using it immediately, and seek medical attention if necessary.

Interactions with medications

Spirulina powder may interact with certain medications, such as blood thinners, immunosuppressants, or drugs for thyroid disorders, diabetes, or high blood pressure.

If you take any medications, consult your healthcare provider before adding Spirulina to your diet to avoid potentially negative interactions.

Heavy metal toxicity

Spirulina is known for its ability to absorb heavy metals from the environment, such as mercury, lead, arsenic etc. It’s essential to ensure that the Spirulina powder you use is not contaminated with these toxins.

Some Spirulina products may be grown in polluted waters or exposed to contaminants during processing, packaging, or transportation. Look for Spirulina powder that is grown on certified organic farmland, is non-toxic, and free from contaminants.

Avoid any potential side effects

In conclusion, Spirulina side effects are generally mild and rare, and people can safely consume Spirulina powder as part of a healthy and balanced diet.

To avoid potential side effects, choose high-quality Spirulina powder that is lab tested, grown under organic conditions, controlled, safe, and follows the recommended dosage.

Spirulina can provide many health benefits, such as boosting immunity, enhancing skin health, and increasing exercise performance, without causing any harm. With Fresh Spirulina Powder, you can enjoy the benefits of Spirulina with confidence and peace of mind.

Propper dosage

Spirulina is food, not a drug or medicine and has no known serious contraindications taken in the proper dosage. The recommended dose, as mentioned earlier is 3 to 5 g distributed among the main meals (20gr per day in total, can be taken in one go as well).

Overactivity of the thyroid gland

In the case of hypothyroidism if you want to consume spirulina at the beginning you should consult a doctor. Although the alga spirulina contains a minimal amount of iodine, it can influence the thyroid gland. It is recommended that people with hypothyroidism always consume minimal doses, and go up week by week. Spirulina is generally contraindicated (should not be used in the case in question) for hyperthyroidism.

In other cases consult a doctor

Pregnant women and young children should consult with a qualified healthcare professional before deciding to consume spirulina.

Patients with kidney failure or problems with the kidneys need to limit protein intake to alleviate elevated toxin levels and protect kidney function. Therefore, before consuming spirulina consult with your doctor or dietetic professional and establish the suitability to consume spirulina and the appropriate dose.

Limiting protein intake for the above-mentioned patients does not mean taking any protein, as these are essential for the maintenance of normal body activities. You should only control and reduce your intake to reduce extra loads on the kidneys and always strive to have the highest quality of protein. In this sense, spirulina is a good choice as it is a complete protein that contains all the essential amino acids we need, although it contains less methionine*, cysteine** and lysine*** compared to meat, egg and milk proteins.

*amino acid, organic compound, A lipotropic, sulphur containing essential amino acid, C 5 H 11 NO 2 S, found in most protein.
**amino acid A sulphur-containing nonessential amino acid C 3 H 7 NO 2 S found in most animal proteins; it readily oxidizes to cysteine.
***amino acid An essential amino acid, C 6 H 14 N 2 O 2 .


  1. Deng, R. and Chow, T.-J. (2010). Hypolipidemic, Antioxidant, and Antiinflammatory Activities of Microalgae Spirulina. Cardiovascular Therapeutics, 28(4), pp.e33–e45. doi:https://doi.org/10.1111/j.1755-5922.2010.00200.x.
  2. Karkos, P.D., Leong, S.C., Karkos, C.D., Sivaji, N. and Assimakopoulos, D.A. (2011). Spirulinain Clinical Practice: Evidence-Based Human Applications. Evidence-Based Complementary and Alternative Medicine, [online] 2011, pp.1–4. doi:https://doi.org/10.1093/ecam/nen058.
  3. Khan, Z., Bhadouria, P. and Bisen, P. (2005). Nutritional and Therapeutic Potential of Spirulina. Current Pharmaceutical Biotechnology, 6(5), pp.373–379. doi:https://doi.org/10.2174/138920105774370607.‌
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Fresh Spirulina

Fresh Spirulina

Founded in Southeast QLD and located on Certified Organic farmland, we are an Australian-made Fresh Spirulina commercial farm. We are subject to the Australia New Zealand Food Standards Code and produce fresh Spirulina using food-grade nutrients only, pay attention to the freshness and health of our spirulina.

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