Chlorella might sound like a cross between a pool cleaner and a certain music festival. It’s actually an awesome superfood that packs some pretty potent health benefits.

Like it’s close cousin spirulina, chlorella is a nutrient-rich freshwater algae typically available as a dark green powder or tablet. It’s loaded with protein, fiber, healthy fats, and antioxidants — and its trending big time as a supplement.

If you’re thinking about hopping on the bandwagon, well hey, it might be a good idea. This green from the sea can support your overall health in some impressive ways, and as long as you’re buying from a reputable manufacturer, it likely doesn’t pose any serious risks.

Here are 10 science-backed benefits of chlorella and what to know about taking it safely.

What’s all the craziness over chlorella about, exactly? Here’s a look at how you might benefit from taking it on the reg.

Chlorella is loaded with nutrients

Chlorella’s a whopping 60 percent protein, and unlike most plant foods, it contains all nine essential amino acids.

It’s also rich in EPA and DHA omega-3 fatty acids, iron, vitamin C, vitamin B-12, plus antioxidants. As an added bonus, it’s got trace amounts of minerals like magnesium, copper, zinc, potassium, and calcium.

In other words, the nutritional stats basically read like a top-of-the-line multivitamin.

It may bolster your immune system

Adding chlorella to your diet just might give your body an extra oomph at warding off infections. The algae contains immunostimulators, which stimulate the immune system and help keep it in fighting form.

In fact, one small study found that taking 5 grams of chlorella daily for 8 weeks enhanced certain markers of immune response in healthy people.

It can help keep your cholesterol in check

High cholesterol can up your risk for heart disease, but taking chlorella along with eating a healthy diet and exercising may help lower total cholesterol and triglycerides in people with mildly high numbers.

The benefit seems to come from chlorella’s high level of carotenoids, antioxidants known to play an important role in heart health.

Chlorella does good things for your gut

Trying to get more prebiotics in your diet? Look no further than chlorella. It’s a rich source of prebiotics like polysaccharides and oligosaccharides, which play a key role in nourishing the good bacteria in your gut and keeping your microbiome healthy.

It fights oxidative damage and stress

Oxidative stress from free radicals causes damage to cells, which over time, can raise the risk for chronic diseases.

Where does chlorella come in? It’s loaded with antioxidant compounds including vitamin C, beta carotene, lycopene, lutein, and chlorophyll, which can help minimize the harm done by free radicals and may help lower chronic disease risk.

Chlorella might help keep blood sugar in check

Managing your blood sugar is major for avoiding type 2 diabetes and promoting overall health. While chlorella isn’t a magic bullet (your best defenses against T2D are eating right, keeping tabs on your weight, and exercising), taking it regularly could help.

Both healthy people and those at high risk for blood sugar issues lowered their fasting blood glucose levels after taking chlorella daily for 12 weeks, one study showed.

It could crank up your workouts

Need a nudge at the gym? Chlorella could help. Thanks to its branched-chain amino acids, taking 6 grams of the stuff daily for 4 weeks was shown to improve exercisers’ oxygen intake, which is a key marker of endurance.

It’s like a security guard for your eyes

Over time, the blue light emitted from the sun can damage the cells in your retina and up the risk for vision problems like age-related macular degeneration. (Phones and laptops emit blue light too, but there’s no evidence that blue light from electronic devices damages your eyes, though it can mess with your sleep.)

Chlorella is a potent source of lutein and zeaxanthin, two antioxidants proven to fight against blue light’s harmful effects and lower macular degeneration risk.

It’s a fish-free source of omega-3s

Fatty fish like salmon and tuna actually get their EPA and DHA omega-3s from eating plants like chlorella. So, if you’re not a fan of seafood or just don’t eat it very often, you can legit go straight to the source and get your omega-3s from algae-based supplements like chlorella.

Chlorella may help ease PMS and period pain

Some research suggests that taking chlorella supplements may help relieve period pain. A study in 44 girls with menstrual cramps found that taking 1.5 grams of chlorella daily for 8 weeks improved symptoms such as cramping, headaches, fatigue, and decreased inflammation.

Is that enough to justify adding chlorella to your diet in the days leading up to your period? You decide.

Chlorella and spirulina have a whole lot in common, but they’re not exactly the same. The nutrient composition of each is a little different, so if you’re thinking about taking one, you might want to base your decision on the vitamin and mineral content that’s more geared towards your health goals.

Gram per gram, chlorella is a little higher in calories than spirulina. It also packs more omega-3s, vitamin A, magnesium, iron, and zinc. So if you’re looking to get more of those nutrients, chlorella might be the better bet.

Chlorella’s typically found as a fine powder, tablets or capsules, or an extract. The plant has a hard cell wall that our digestive tracts can’t break down, so the easiest way to reap all those impressive nutritional benefits is to take the algae as a supplement.

As for how to actually take it: If you’re going for the powdered stuff, experiment with adding it to smoothies, salad dressings, puddings, or even raw desserts. Like spirulina, it’ll turn your food a dark blue-green color.

It also has a slightly vegetal flavor, but it’s pretty easy to mask with other ingredients, like sweet fruit in a smoothie or an acid or citrus juice in a salad dressing.

Opting for a pill or extract? You can take those straight. Just follow the dosing instructions on the supplement packaging.

It’s generally safe to add chlorella to your diet. Just keep in mind that it can have some weird (but not really harmful) side effects and might not be appropriate for people taking certain medications.

  • It might mess with your stomach. Most people who take chlorella don’t have any issues, but it has the potential to cause nausea, diarrhea, cramping, and gas. Try taking it for the first time on a day when you’ll just be hanging out at home.
  • It can turn poop or breast milk green. Like other intensely colored foods (hey beets!), chlorella can change the color of your poop. It can also affect milk color in those who are breastfeeding, but the color change isn’t bad for your baby.
  • It might make your skin more sun-sensitive. Chlorella could potentially make you more prone to sunburn, so if you’re taking large quantities, be smart about minimizing your exposure to direct sunlight.
  • You could have an allergic reaction. Severe ones like anaphylaxis, though rare, have been reported.
  • It’s not for people on blood thinners. Chlorella is high in vitamin K, which can affect blood clotting and reduce the effectiveness of blood thinning meds. If you take warfarin, talk with your doctor before adding chlorella to your diet.

One last thing to keep in mind: Like all supplements, chlorella-based products aren’t =tested for safety before hitting the market.

Before buying a powder, pill, or extract, do your research to make sure the supplement is high-quality and is verified by a third party like United States Pharmacopeia, NSF International, or Consumer Lab.


Chlorella is a nutrient-rich freshwater algae that can deliver a slew of potential health perks. It’s generally safe to take as a supplement, just make sure you’re picking a quality product before giving it a try.

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