In 2024, the Food and Agriculture Organization of the United Nations (FAO) encouraged the growth and use of spiruline, a type of blue-green algae, especially in developing countries, to help reduce malnutrition. This organism is known for its high nutritional value, with around 65 grams of protein per 100 grams. It also contains essential amino acids, gamma-linolenic acid, which may help reduce body fat and preserve muscle mass, as well as various minerals like magnesium, phosphorus, calcium, and iron. Additionally, spiruline is rich in vitamins, including provitamin A (beta-carotene) and all the B group vitamins, along with vitamins D, E, and K. It also contains phycocyanin, a blue pigment with antioxidant properties. While spiruline has many benefits, there are some limitations. According to the Santé website and the French Agency for Food, Environmental and Occupational Health & Safety (Anses), the vitamin B12 found in spiruline is not effectively absorbed by the body, making it an insufficient source for vegetarians and vegans. In the areas of cardiovascular and metabolic health, recent research has provided useful insights. A 2021 meta-analysis by Piotr Machowiec combined five randomized controlled trials and found that people taking spiruline supplements experienced a statistically significant decrease in blood pressure, especially those who were already hypertensive. However, the researchers noted that further studies are needed to confirm these findings, as the effects of magnesium, amino acids, and phycocyanin on vascular metabolism are already known. In the same year, a meta-analysis by Elaheh Hatami found that spiruline supplementation improved fasting blood sugar levels and several lipid parameters in people with type 2 diabetes. In 2023, a study by Iman Rahnama showed that spiruline can lower total cholesterol, LDL-cholesterol (often called "bad cholesterol"), and triglycerides, while increasing HDL-cholesterol (or "good cholesterol") in people who took it. Overall, these studies suggest that spiruline can have positive effects on blood cholesterol levels. For athletes, spiruline may offer benefits in muscle repair, energy production, and reducing oxidative stress from physical exertion. In a 2010 pilot study involving nine athletes, Maria Kalafati found that spiruline could improve physical performance and aid in muscle recovery. A 2025 study by Jordi Vignaud on rats suggested that a spiruline extract could enhance physical performance and bring about positive changes in muscle tissue. However, these results need to be confirmed in human trials to determine spiruline's true effectiveness in athletic performance. Quality control remains a key concern when using spiruline supplements. Anses, in a 2017 article, warned about the risk of contamination with cyanotoxins, bacteria, or heavy metals depending on the production source. It recommended that consumers prefer products from well-controlled supply chains and ensure compliance with French regulations, product traceability, and manufacturer identification. Anses also advises against using spiruline for individuals with allergies or phenylketonuria, a rare genetic disorder that affects the body’s ability to process phenylalanine. Between 2014 and 2017, 49 cases of adverse effects were reported, with 10 cases likely linked to spiruline consumption. The agency also highlights potential side effects such as allergies or digestive issues, reminding users that spiruline should be used with proper dosing and tailored to individual needs. As with any dietary supplement, consulting a healthcare professional before starting a regimen is important. Overall, recent studies suggest that spiruline has real, though sometimes modest, health benefits.