There is no established evidence that adding spirulina to a fast prevents serious illness or produces a special “detox” effect. Most human spirulina studies examine supplementation within a normal diet, not fasting protocols.
Reviews of cardiometabolic research describe possible changes in some risk markers, but the trials use different products, doses and study designs. The results do not establish spirulina fasting as a treatment.
Read a 2024 narrative review of cardiometabolic research.
Fasting is not suitable for everyone. People who are pregnant, under 18, living with diabetes, taking medication or managing a health condition should seek qualified medical advice before fasting.