Spirulina Blue Extra 200 Tablets

Spirulina is sold on nutrient density but studied for other things, so these are the questions our naturopaths ask in store before recommending it.

A good fit if

• You want a concentrated whole food rather than a single nutrient
• You'll buy from a supplier that tests each batch for contamination
• You're interested in the blood lipid research and will give it time
• You'll use it in a smoothie and don't mind the taste

Check with us first if

• You have an autoimmune condition. Spirulina is widely described as stimulating the immune system, and we haven't found research that settles what that means for you.
• You have phenylketonuria (PKU). It's a concentrated protein source, and we haven't found reliable information on its phenylalanine content.
• You take any prescription medicine. Beyond testing with blood thinners, we haven't found interaction data.
• You're buying for a child. We haven't found safety data in children.
• You're not sure whether you want spirulina or chlorella. They're different algae with different rules.

• Powder. Best known for: The simplest way to take a meaningful amount. Absorption: Whole dried algae, with nothing removed. Typical use: It has a strong taste, so most people blend it rather than stir it in.
• Tablets. Best known for: Getting past the flavour. Absorption: The same material, pressed into tablets. Typical use: You will need several to match a serve of powder.
• C-phycocyanin extract. Best known for: The isolated blue pigment, the most studied part of spirulina. Absorption: An extract rather than the whole alga. Typical use: Studied at around 1 g a day of phycocyanin in the bleeding and liver research.
• Arthrospira platensis or maxima on the label. Best known for: The Schedule 1 names that allow it to be used as an active ingredient. Absorption: Not a different form, just a different regulatory name. Typical use: "Spirulina" on its own is allowed only as a carrier (excipient) in Schedule 1.
• Chlorella instead. Best known for: A different green alga entirely. Absorption: Contains iodine, which the rules list as a required component. Typical use: For internal use, it is capped below 300 micrograms of iodine a day.

Reference values. None. Spirulina is a food rather than a single nutrient, so there's no NHMRC reference value for it.

Typical supplemental range. Australian labels usually provide 3 to 10 g a day. A research review gives about 3 to 10 g a day as a safe amount for adults, though that's a review's opinion rather than a legal limit. The bleeding and liver safety testing used 2.3 g a day of a water-based extract, providing roughly 1 g of phycocyanin.

Upper level. There's no NHMRC upper limit, and Australia's permitted ingredients list (Schedule 1) sets no dose limit for Arthrospira platensis (item 702) or Arthrospira maxima (item 701). The 3 to 10 g a day figure from research is the closest thing to a ceiling, but it isn't a legal limit.

Worth knowing. For most people, where it was grown matters more than the dose, because open-pond growing is where the contamination question comes in. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Spirulina powder: the food itself; commonly 3 to 10 g a day
• Green smoothie blends: often a small fraction of the serve; check the panel

If any of these sound like you, talk to one of our naturopaths or your doctor before you start.

• Pregnancy and breastfeeding. Items 701, 702 and 4710 carry no Schedule 1 pregnancy warning, but we found no human data on pregnancy or breastfeeding.
• Contamination. Depending on how it is grown, spirulina may carry microcystins and other toxins. The research reports this as contested, not settled.
• You have an autoimmune condition. Spirulina is widely described as stimulating the immune system, and we found no source on what that means for your health in practice.
• You have phenylketonuria (PKU). Spirulina is a concentrated protein source, and we found no source on its phenylalanine content.
• Children. No spirulina item has an age limit, and we found no safety data for children.
• Medicine interactions. We found no data beyond direct blood-thinning tests, which showed no change in platelet activation at 2.3 g/day of water-based extract.
• Don't confuse it with chlorella (items 1343, 1345), which contains iodine as a required component and is capped below 300 micrograms of iodine a day for internal use.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before you start.