We test and review fitness products based on an independent, multi-point methodology. If you use our links to purchase something, we may earn a commission. Read our disclosures.
If you’ve been trying to squeeze more vitamins and minerals into your daily routine, you may have considered a greens powder. While they’re not a replacement for a healthy diet, greens powders certainly can help you consume more of the nutrients associated with fruits and veggies.
However, greens powders, like most supplements, come with a list of side effects to be aware of.
RELATED: Creatine Side Effects
Even if it’s a high-quality greens powder from a reputable brand, there are still risks you should know about. In this guide to super greens powder side effects, we’ll explore all of the potential risks and discuss who should and who shouldn’t take greens powder.
Medical disclaimer: This article is intended for educational and informational purposes only. It is not intended as a substitute for medical advice. For health advice, contact a licensed healthcare provider.
What Are Greens Powders?
Greens powders are a type of plant-based dietary supplement containing multiple ingredients—sometimes nearing 100—aimed at supporting daily micronutrient intake. Greens powders contain whole-food-sourced ingredients as powders, such as leafy greens and cruciferous vegetables like broccoli. “Superfoods” like chlorella, spirulina, and wheatgrass are usually included for their antioxidant content and anti-inflammatory properties.
Some of the best greens powder supplements also contain fruit extracts, like acerola cherry extract, and adaptogens, such as ashwagandha, ginseng, and green tea extract. Additionally, it’s common to see microbiome support on the ingredients list: Probiotics, prebiotics, fiber, and digestive enzymes are often included.
The supposed health benefits of green superfood powders include immune system support, increased energy levels, and improved overall health and wellness. Anecdotally, buyers claim that greens powders help with weight loss, digestion, gut health, stress levels, mood, and more.
Super Greens Powder Side Effects
Unfortunately, everything is not always as it seems: Ahead, learn about nine potential side effects of super greens powders.
Bloating is one of the most common complaints about greens supplements. As anyone who’s experienced bloating knows, it can be wildly inconsistent, random, and frustrating.
Because greens powders contain so many ingredients, it’s impossible to know what exactly causes bloating for each individual. There are some common culprits, though, including fiber, prebiotics, probiotics, stevia, artificial sweeteners, and maltodextrin, a type of highly processed carbohydrate.
That said, sometimes bloating is temporary and is just a sign of your body adjusting to new substances. It may go away if you continue to take the greens consistently over time; if it doesn’t, it’s recommended to stop taking the supplement.
RELATED: Best Greens Powders for Bloating
Like bloating, cramping is a highly variable and individual side effect. Individuals with gastrointestinal sensitivities to certain foods and ingredients, particularly sweeteners, may experience cramping after taking a greens powder. Often, sugar alcohols such as erythritol are to blame. Probiotics may also cause cramps in some people.
Loose Bowel Movements
If you’re new to fiber and probiotics, your first swig of greens powder might make you sprint to the bathroom. Suddenly introducing a swath of probiotics, fiber, and digestive enzymes to your body could put your gastrointestinal tract into overdrive. Like bloating, this side effect may wane over time as your body becomes accustomed to the ingredients in the greens powder. If you’re having consistent diarrhea, stop taking the greens powder and see if things go back to normal.
RELATED: Best Probiotics
Though much less common than loose bowel movements, some people experience constipation after taking greens powders. This may happen if the greens powder is high in insoluble fiber. This type of fiber cannot be absorbed by the body and adds more bulk to stool. Normally, more fiber is a good thing—most Americans don’t consume enough1—but for some people, consuming too much fiber might make things worse, according to a 2005 review in the American Journal of Gastroenterology2.
Greens powders may cause acid reflux or worsen existing acid reflux if they are high in caffeine or citrus ingredients or flavors. While the jury is still out on whether caffeine is a definitive gastroesophageal reflux disease (GERD) trigger3, it’s anecdotally common.
Citrus has been identified as a GERD trigger, according to a 2021 review of studies in the journal Preventive Nutrition and Food Science4.
Avoiding acid reflux is really a matter of knowing your personal triggers and reading the ingredients label to avoid any side effects.
Greens powders may contain allergens, including soy, gluten, tree nuts, and coconut. If you have known allergens, it’s critical that you read—no, study—the entirety of the supplements facts label. Because greens powders contain so many ingredients, it can be tough to tease out exactly what’s in them, so take your time if you have allergies. Additionally, remember to always read the full ingredients list, not just the nutritional information.
If you currently take prescription medications, talk with your doctor before adding greens supplements into your diet. There are a lot of ingredients in greens powders and many may interact with medications. For instance, if you’re taking a blood thinner like warfarin, look for the vitamin K content. Vitamin K interferes with warfarin5 because it is key for coagulation, or the formation of blood clots. Suddenly introducing a megadose of vitamin K into your diet when you’re on an anticoagulant can have unintended consequences.
Heavy Metal Buildup
This may be the most alarming potential side effect of greens powders. As registered dietitian nutritionist Destini Moody points out in our Green Vibrance review, “One of the dangers of consuming greens powders is potential exposure to lead and other heavy metals. This is because these metals can be in the soil in which the vegetables are grown and can be present even in organically grown produce.” Because greens powders are so highly concentrated, the risk may be higher than from fresh produce.
Symptoms of heavy metal toxicity vary depending on the type of metal you are exposed to. For example, ingesting cadmium can cause a variety of gastrointestinal issues, including nausea and vomiting, according to the Centers for Disease Control and Prevention (CDC)6.
Lead, mercury, arsenic, cadmium, and thallium are the most worrisome metals according to the Cleveland Clinic7, and Consumer Reports has reported that independent testing did detect some of these in greens powders. In 2016, Consumer Reports testing8 revealed lead, cadmium, and arsenic contamination; in 2019, a repeated test9 again found lead contamination.
Jitters or Nervousness
Greens powders that contain caffeine may cause jittery reactions in people who aren’t used to the effects of caffeine. Typically, greens powders don’t contain much caffeine—nothing like a strong pre-workout powder—but those who are sensitive to caffeine should double-check the label and ingredients ist.
How to Avoid Side Effects From Greens Powders
Truthfully, the only 100% guaranteed way to avoid side effects from greens supplements is not to take them. However, you can minimize your risk by following these steps:
- Choose a product that has undergone third-party testing and is verified to be free from contaminants, including heavy metals and allergens
- Thoroughly read ingredients lists and avoid any products with items that you are allergic or sensitive to
- Avoid greens powders high in nutrients that interfere with medications you are taking
- Avoid greens powders that contain ingredients that you know trigger acid reflux for you
If you’re having trouble finding a greens powder that works for you, try consulting with a registered dietitian—or sticking to whole fruits and vegetables.
Who Should Take Greens Powders? Who Shouldn’t?
The majority of healthy individuals can take greens powders without any problems. But, there are several groups of people who should avoid greens powders altogether or talk with a doctor or medical dietitian nutritionist before trying this type of supplement.
Who shouldn’t take greens powders:
- Individuals who are pregnant or breastfeeding
- People who are managing chronic diseases (without first talking to a doctor)
- People who are taking prescription medications (without first talking to a doctor)
- Those with allergies to common greens powder ingredients
- Anyone subject to heavy metal buildup in the body, such as those with Wilson’s disease (unless it is a third-party tested product with proof that there are no heavy metal contaminants in the powder)
- Athletes who are subject to drug testing (unless it is a third-party tested product with proof that it does not contain substances banned by the World Anti-Doping Agency)
Super Greens Powders Side Effects: Final Thoughts
There are plenty of potential benefits of greens powders, but there are also several risks to consider. As with all supplements, it’s important to do thorough research and, if applicable, talk to your healthcare provider about how a supplement might impact chronic disease management, allergies, and/or medication protocols.
Super Greens Powders Side Effects: Q&A
Do greens powders get rid of toxins?
No, greens powders do not rid your body of toxins—and you should run away from any products that claim to support detoxification. Your body’s natural processes take care of any toxins, wastes, or byproducts; a greens powder is simply a vessel for consuming more vitamins and minerals.
Are greens powders good for you?
Greens powders may provide you with nutrients that are tough to get enough of each day, such as vitamin A, vitamin C, vitamin K, calcium, and magnesium. However, while these supplements do contain powdered green vegetables and other nutrient-dense ingredients, they are not a replacement for a nutritious diet. For optimal health, it’s important to consume plenty of whole fruits, vegetables, grains, protein, and healthy fats each day.
Is it safe to drink green powder every day?
If the greens powder does not contain any ingredients to which you are allergic or sensitive, does not contain ingredients that interfere with medications you take, and is free from contaminants, then yes, it’s theoretically safe to drink daily. It’s never a bad idea to consult with a nutrition professional if you’re unsure about a specific product.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any diseases.
- Akbar A, Shreenath AP. High Fiber Diet. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559033/
- Müller-Lissner SA, Kamm MA, Scarpignato C, Wald A. Myths and misconceptions about chronic constipation. Am J Gastroenterol. 2005;100(1):232-242. doi:10.1111/j.1572-0241.2005.40885.x
- Mehta RS, Song M, Staller K, Chan AT. Association Between Beverage Intake and Incidence of Gastroesophageal Reflux Symptoms. Clin Gastroenterol Hepatol. 2020;18(10):2226-2233.e4. doi:10.1016/j.cgh.2019.11.040
- Heidarzadeh-Esfahani N, Soleimani D, Hajiahmadi S, Moradi S, Heidarzadeh N, Nachvak SM. Dietary Intake in Relation to the Risk of Reflux Disease: A Systematic Review. Prev Nutr Food Sci. 2021;26(4):367-379. doi:10.3746/pnf.2021.26.4.367
- Lurie Y, Loebstein R, Kurnik D, Almog S, Halkin H. Warfarin and vitamin K intake in the era of pharmacogenetics. Br J Clin Pharmacol. 2010;70(2):164-170. doi:10.1111/j.1365-2125.2010.03672.x
- Agency for Toxic Substances and Disease Registry. What Health Effects Are Associated With Acute High-Dose Cadmium Exposure? Centers for Disease Control and Prevention.
- Cleveland Clinic. Heavy Metal Poisoning (Toxicity).
- Consumer Reports. ConsumerLab Finds Lead, Cadmium and Arsenic Contamination in Greens and Whole Foods Supplements. 2016;08(08)
- Consumer Reports. Contamination Still an Issue in Some Greens and Whole Food Products, ConsumerLab Tests Reveal. 2019;01(31)
Two fitness experts used and analyzed this popular pre-workout for our Six Star Pre-Workout review. Read more
Creatine is a very popular supplement in fitness. However, it’s often missed that there are foods with creatine that you are likely already familiar with. Read more
3…2…1…go! We’ve tested and highlighted the best CrossFit apps to help you get the most from your next at-home AMRAP. Read more
In this NordicTrack C2200 treadmill review, we look at an affordable, discontinued walking treadmill with neat features. Read more