Spirulina, or blue green algae, has a number of healthy nutrients, from B vitamins to iron and from vitamin E to zinc. It's also high in protein and antioxidants. You may wish to take spirulina tablets to boost your immune system to ward off disease or to treat your allergies. When choosing tablets, it's important to find a brand that you can trust. Tablets containing spirulina can be contaminated with heavy metals if the algae was grown in a natural setting. The best tablets are therefore those tested for contaminants and produced in a laboratory under controlled conditions.
Look for spirulina tablets that are tested for contaminants. Spirulina can be contaminated with bacteria or microcystins, which can damage your liver. Contaminated spirulina tablets are most likely not safe to consume, as you may end up with an infection in your throat or nausea and diarrhea. If the bottle of spirulina tablets does not clearly state that they were tested and are free of bacteria and other toxins, you may want to find a bottle that is labeled or take the time to call the manufacturer. If you do not get a clear answer, leave the bottle on the shelf.
You may want to buy spirulina tablets that are produced in a laboratory under controlled and cleanly conditions. Spirulina grown in natural bodies of water such as lakes are more likely to contain bacteria or to be contaminated with toxins, especially if the water they were grown in contained metal contaminants. Lab-grown spirulina is also more likely to have a standardized quality. The amount of sunlight and the water temperature can affect the nutrient value of the algae. Those factors can be more easily controlled in a laboratory.
Some manufacturers may dilute their spirulina tablets with starch, which helps to bind the tablet, while others use only spirulina in the tablet, which leads to a more potent tablet. Some tablets may contain up to 20 percent fillers or binders. Your body may not absorb the nutrients from diluted tablet as effectively as from pure tablets.
If you are considering taking spirulina, you should exercise care before taking the tablets. If you have an auto-immune disorder, spirulina may counteract any immunosuppresent medication you are taking. You should also avoid taking spirulina if you suffer from phenylketonuria, as the tablets contain phenylalanine, which can worsen your conditions. Don't take the tablets if you are pregnant or breastfeeding, as there is not enough information on the safety of the tablets for pregnant women.