Quick answer
Spirulina is a blue-green algae that's about 60% protein by weight and rich in iron, antioxidants and pigments like phycocyanin. Human studies have used 1 to 10 grams a day. A meta-analysis of randomized trials found spirulina improved blood lipid levels, and a small trial in trained men found better endurance after 4 weeks at 6 grams a day.* Man Greens contains 5,000 mg (5 g) of organic spirulina per scoop.
What is spirulina?
Spirulina (Arthrospira platensis) is a cyanobacterium grown in fresh water and dried into a powder. It's one of the most nutrient-dense whole foods by weight, which is why it's the base of Man Greens.
What 5 g of spirulina provides
- About 3 g of protein
- Iron, B vitamins, and the antioxidant pigment phycocyanin
- Note: most of the vitamin B12 in spirulina is a form the body can't use, so don't rely on it for B12.
What the research shows
| Study | Who | Dose | Length | Finding vs placebo |
|---|---|---|---|---|
| Serban et al., 2016 (meta-analysis) | 7 randomized trials, 522 participants | 1 to 10 g/day | Various | Improved total cholesterol, LDL, triglycerides and HDL |
| Kalafati et al., 2010 | 9 moderately trained men | 6 g/day | 4 weeks | Longer time to fatigue; more fat burned during exercise |
These studies tested spirulina on its own, not Man Greens.
Man Greens dose vs studied dose
Man Greens provides 5,000 mg of organic spirulina per scoop, within the 1 to 10 g range used in human trials.
Why testing matters for spirulina
Spirulina grown in contaminated water can pick up heavy metals or toxins from other algae. Buy spirulina, or a greens powder containing it, that publishes lab testing for contaminants. Man Greens publishes a batch Certificate of Analysis from an ISO 17025 accredited lab.
Safety
Tested spirulina is generally well tolerated. Avoid it if you have phenylketonuria (PKU). Talk to your doctor first if you have an autoimmune condition or take immune-suppressing medication or blood thinners.
FAQ
How much spirulina should you take a day?
Human studies used 1 to 10 grams a day; many used 2 to 6 grams.
Is spirulina good for men?
It's a dense source of protein and micronutrients, and one small trial in trained men found better endurance at 6 g a day.*
References
- Serban MC, Sahebkar A, Dragan S, et al. A systematic review and meta-analysis of the impact of Spirulina supplementation on plasma lipid concentrations. Clin Nutr. 2016;35(4):842-851.
- Kalafati M, Jamurtas AZ, Nikolaidis MG, et al. Ergogenic and antioxidant effects of spirulina supplementation in humans. Med Sci Sports Exerc. 2010;42(1):142-151.
Spirulina is one of 8 ingredients in Man Greens. See every dose on the ingredients and testing page.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.