What are chlorella’s main drawbacks?

Because chlorella contains a cellulose cell wall (unlike spirulina), it must undergo mechanical processing to break down these cell walls before human consumption to avoid gastrointestinal side effects like nausea, vomiting, and stomach pain.^[1] Furthermore, some studies have confirmed that chlorella is an allergen, so some individuals (notably children) may be sensitive to it or want to avoid its consumption.^[2]