Spirulina, weight loss and blood fats: a review
What it found
In people, spirulina supplements were linked to lower body weight, waist size, body mass index and appetite, and to improvements in blood fats such as cholesterol and triglycerides.
The authors say larger trials are still needed.
What they found
Studies in people
Weight and body fat
In several trials in people with obesity, spirulina taken for 12 weeks to 3 months led to lower body weight, waist circumference, body fat and body mass index compared with placebo or baseline. One study found a reduction in appetite.
Blood lipids in people
Many human trials found that spirulina lowered total cholesterol, LDL cholesterol and triglycerides, and raised HDL cholesterol. For example, in patients with heart disease and high cholesterol, 2 g or 4 g of spirulina for 3 months lowered total cholesterol by 22.4% and 33.5%, and LDL by 31% and 45%.
Blood sugar and diabetes
In people with type 2 diabetes, spirulina lowered fasting blood glucose, postprandial blood glucose, HbA1c and triglycerides. A meta-analysis of 12 human studies found a small drop in fasting blood glucose.
Blood pressure and heart risk
In people with high blood pressure, spirulina lowered systolic blood pressure and arterial stiffness. A meta-analysis found a drop in diastolic blood pressure.
Animal and lab studies
Animal and lab studies
In rats and mice, spirulina improved lipid profiles, increased HDL and lowered LDL, triglycerides and total cholesterol. It also changed gut bacteria in ways that may lower blood lipids.
Other findings
How it might work
Spirulina contains phycocyanin, which may reduce oxidative stress and inflammation. It may also reduce fat absorption, improve satiety and inhibit pancreatic lipase.
What the authors conclude
“Overall, the evidence in the literature suggests that spirulina improves several well-established CVD risk factors including hyperlipidaemia and seems to provide benefits around weight loss.”
Also in their conclusions
- They conclude that spirulina improves several risk factors for heart disease, including high blood lipids, and seems to help with weight loss.
- They say that supplementing 2 to 8 g per day may improve lipid profiles, aid weight loss and reduce BMI.
- They call for further research including larger clinical trials to confirm these benefits.
How it was done
Metabolic syndrome, obesity and high blood fats are on the rise, and spirulina is a low-cost supplement that has been studied for these problems. The authors wanted to review its effects on obesity and blood fats and discuss how it might work.
The authors reviewed clinical and preclinical trials of spirulina in people and animals, looking at weight loss and blood lipid changes. The human studies included healthy people and those with conditions such as obesity, high blood pressure, heart disease, diabetes, kidney disease and high cholesterol, and used doses from 1 g to 8 g per day for up to 24 weeks.
What it can’t tell you
- The human trials were often small and used different doses, durations and patient groups, so the size of the effect varies.
- Some of the evidence comes from animal studies, which cannot show what happens in people.
- The review cannot prove that spirulina itself causes the improvements, because other factors like diet and exercise may also play a role.
Who paid
- Conflicts
- Competing interests: JJD is the author of The Salt Fix and Superfuel. JO is owner of a nutraceutical company but the company does not sell spirulina.
- Authors work at
- Mid America Heart Institute, USA; Baystate Medical Center, USA; University of Massachusetts, United States
The paper
- Title
- Effects of spirulina on weight loss and blood lipids: a review
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- DiNicolantonio JJ, Bhat AG, OKeefe J (2020). Effects of spirulina on weight loss and blood lipids: a review. Open heart. doi:10.1136/openhrt-2018-001003Free full textPubMed 32201580DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error