Evidence Level
Chlorella is a green microalga that has garnered interest for its potential health benefits. Research highlights its effects on lipid metabolism and immune function. Kwak et al. (2012) demonstrated significant activation of natural killer cells in humans following 8 weeks of supplementation with 5g/day of Chlorella. Additionally, Ryu et al. (2014) reported reductions in total cholesterol and LDL-C levels in mildly hypercholesterolemic adults consuming Chlorella daily.
Recent systematic reviews have further elucidated Chlorella's lipid-lowering effects. Sherafati et al. (2022) found that Chlorella vulgaris supplementation significantly reduced total cholesterol (-7.47 mg/dL, p<0.05) and LDL-C (-7.71 mg/dL, p<0.05) in adults. Similarly, Fallah et al. (2018) reported significant reductions in total cholesterol, LDL-C, systolic and diastolic blood pressure, and fasting blood glucose across 19 RCTs (n=797). However, Pinto-Leite et al. (2025) found that Chlorella had no significant effect on blood pressure or lipemia compared to Spirulina.
Chlorella's hepatoprotective effects were demonstrated by Azocar & Diaz (2013) in hepatitis C patients, though the mechanism requires further elucidation. The broken cell wall form is essential for digestibility, as intact Chlorella cell walls are indigestible by humans. Lacurezeanu & Vodnar (2025) found that both Arthrospira platensis and Chlorella vulgaris improve iron status by enhancing hematological parameters and antioxidant defenses in vivo studies.
Overall, while Chlorella shows promise for lipid-lowering and immune modulation, more robust human trials are needed to confirm its benefits and elucidate mechanisms of action.