*Update*
Things are never as simple as they appear apparently. A recent post by Dr. Andrew Weil is critical of Spirulina and he claims it is not safe.

Is Spirulina safe? No. To my mind spirulina never has been safe. I have been warning against it for years, and the finding that a neurotoxin found in some spirulina may be related to neurological diseases is the main reason to avoid it.

See the full article here:
https://www.drweil.com/diet-nutrition/food-safety/is-spirulina-safe/

It would be interesting to get some real information to know for sure.

Spirulina is an algae that grows in highly alkaline, warm fresh water bodies. Today spirulina is sold in powder or pill form as a nutritional supplement. The powder is a great addition in smoothies, drinks or other foods.  Historically spirulina has been a food source as far back as the 16th century Aztecs. Other sources claim “It is believed that the use of Spirulina as a food source in Chad, the “Dead Heart of Africa”, dates as far back as the 9th century Kanem Empire.” (source: Squidoo lens, Using Spirulina)

Using Spirulina

To use spirulina, simply add to smoothies, drinks or other foods. When adding spirulina to smoothies, use approximately 1 teaspoon per 16 oz cup.

Notable Spirulina Nutritional Benefits

• High Protein and Amino Acid Content (~60% complete protein, compared to beef which contains ~20% protein)
• Vitamin B12
• Other nutrients in spirulina include Iron, Potassium, Magnesium, Sodium, Calcium
• Easily digestible

Buy Organic Spirulina Online

More spirulina resources

• 1 – Wikipedia – Spirulina Dietary Supplement
• 2 – Squidoo lens – Using Spirulina
• 3 – Hectic Life – Healthy Girl – What is Spirulina and what are it’s health benefits?
• 4 – IIMSAM – Intergovernmental Institution for the use of Micro Algae Spirulina Against Malnutrition
• 5 – What is Spirulina?