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Are Greens Supplements Worth It? Dietitian Review

Greens supplements are a hot topic in the world of health and wellness. With each Instagram story, Reel, or TikTok you see there is more than likely an influencer taking their “greens and reds” every morning before they begin their day. Common claims of greens supplements include decreased bloating and promotes a strong immune system. But what benefit do they truly give? 

There are a variety of greens supplements on the market with many different ingredients making it hard to define them. Most have vitamins, minerals, and some algae like Spirulina and Chlorella. Both algae may seem odd to add into a supplement, but there is research that shows that they do have nutrients that are needed in humans (1,2). Given the nutrients that are in greens supplements it can give the same benefit as a multivitamin just with added fiber and friendly bacteria to your digestive tract.

If you desire to take a daily greens supplement in the morning you may not need the extra supplement like a multivitamin. However, I always suggest checking with your doctor before you start taking any supplement. Question all ingredients!

Times a greens powder may be helpful

  1. Those who travel a lot that aren’t able to consume enough fruits/vegetables while being on the go may benefit from adding a greens supplement into their day. 
  2. Those who may not get enough servings of fruits and vegetables can use a greens supplement for extra nutrients that they may otherwise be missing.
  3. If taking a greens supplement helps you drink water and you like it as a part of your day, great! You know your body best. 

Before taking a greens supplement

Some greens supplements may be harmful to people with specific medical concerns. Those who may not benefit from a greens supplement: 

  1. Those who are pregnant or breastfeeding: some of the ingredients in greens with a prenatal vitamin may provide an unsafe dose of nutrients. 
  2. People taking prescription medications: some medications have specific drug/nutrient interactions. For instance, if you are taking a blood thinner called Warfarin, you may have to limit the amount of vitamin K you have to make sure the drug is working. If you are thinking about a greens supplement and are taking medications, please talk to your doctor.
  3. People with kidney disease: Those with kidney disease must take extra care when choosing the foods that they eat. Potassium, a nutrient that is in a variety of supplements and fruits/veggies, is one of the minerals to watch. Having too much in a day can increase the risk for a buildup of potassium which can cause harm and is unsafe.
  4. Those with allergies: A variety of greens supplements include ingredients that contain allergens, look over ingredient labels to avoid bad reactions.
  5. Professional and college athletes: Look for the label NSF certified for sport if you are an athlete and wish to take greens. 
  6. Those with digestive problems: Some supplements include ingredients that can worsen digestive problems (IBS). If you know you have trouble digesting some foods, then you may not want to take a greens supplement. 
  7. Those taking a vitamin and mineral supplement: Since most greens supplements contain similar ingredients to that of a multivitamin-mineral supplement, it can become easy to have too much of a specific nutrients. This can cause bad side effects- at times unsafe. 

What are the drawbacks to taking greens supplements

Most greens supplements only contain 1-2 fiber sources and friendly bacteria for gut health (that’s not much). Green supplements don’t have the added benefits of eating fruits/veggies with fiber, nutrient variety, and hydration. They won’t help you feel full either. 


The cost behind these supplements are also high per serving, definitely not cost effective. 

Research on greens powder

Most research used by supplement companies to prove their benefits are studies on eating fruit/vegetables. The research behind the greens supplements are weak (from over 10 years ago with bias), making the claims not backed by science.

Basically, if you choose to take a greens supplement, choose those that are USP and NSF certified. Supplements are not looked over by the FDA, it is important to choose products that have some form of testing. When looking over product information on websites, be sure to avoid claims that appear false like “The best superfood product”, “Decreased bloating” or “Backed by the latest evidence”.  These claims promote the product as having more value, giving the most benefit.  Check out my guide to buying high quality supplements.

Main takeaway: Green powder is not meant to replace fruit/veggie intake. Work on your eating habits and focus on balanced meals with plenty of produce.To conclude, you may get more nutrition from eating fruits/vegetables than drinking a greens supplement. Greens have not been proven to be harmful, and could be used in place of a multivitamin if you wish. Try making a green smoothie or even a green juice!

Greens Powders Study Conclusions:

Article 1 Published November 6, 2008: This study looked at the acidic content of the urine of 34 healthy men and women. The hypothesis is that standard Western Diets increase urinary pH values, and vegetables/fruits properties are akalitic, increasing the pH of urine. To study this they took the pH of their urine at the first urination of the morning. They collected their urine for one week prior to supplementation with the greens, then in the second week of the 21 day trial the participants began taking the greens supplement. The supplement used was Greens+ from Genuine Health Toronto. The mean pH from baseline improved in some participants and in others the pH decreased and became more acidic. Those who had an improvement in pH started with a low pH at baseline.

However, the results were not statistically significant (p-value .031) indicating need for additional research. Considerations: Product and urine sticks were provided by Genuine Health Toronto and the authors were all a part of the research board from Genuine health (although they do not have stock in the company or ability to directly benefit from product sales). (3)

Article 2 Published August 3, 2011: This study measured the in vivo and in vitro effects of polyphenolic antioxidants from Greens +. Using 10 participants (5 males and 5 females) and measuring the antioxidant capacity in lipids. Taking 3 spoonfuls of Greens+ a day showed a minor increase in antioxidant capacity in human subjects (not statistically significant). 6 spoonfuls had significant findings. This study was funded by Genuine health and the products were provided by Genuine health (maker of Greens+). (4)

Article 3 Published April 15, 2008: This study measured the impact of greens supplements on blood pressure. 17 students were enrolled into a control group and 23 students were enrolled into a treatment group through email campaign recruitment at Logan Chiropractic University. This was not a double blind study and no placebo was used. The 23 students in the study group were given a free 90 day supply of a greens supplement supplied by Biopharma Scientific, Inc (San Diego, CA). They were instructed to drink this supplement in 8 oz of water 2 times per day (NanoGreens10). The participant’s blood pressure was taken twice during the data collection period of 90 days. The study group did demonstrate a decrease in systolic and diastolic blood pressure (p-value <.05 is statistically significant) with a p-value of <.001. This study never listed funding sources or acknowledgements leaving room for potential bias. With the small study group size and the potential variability in blood pressure this calls for more research in the correlation of blood pressure and greens supplementation. 

Greens Powder Research References:
  1. Bito T, Okumura E, Fujishima M, Watanabe F. Potential of Chlorella as a dietary supplement to promote human health. Nutrients. 2020;12(9):2524. doi:10.3390/nu12092524
  2. Leech J. 10 health benefits of spirulina. Healthline. https://www.healthline.com/nutrition/10-proven-benefits-of-spirulina#TOC_TITLE_HDR_4. Published October 5, 2018. Accessed September 27, 2022.
  3. Berardi JM, Logan AC, Rao AV. Plant based dietary supplement increases urinary ph. Journal of the International Society of Sports Nutrition. 2008;5(1). doi:10.1186/1550-2783-5-20
  4. Rao V, Balachandran B, Shen H, Logan A, Rao L. In vitro and in vivo antioxidant properties of the plant-based supplement greens+. International Journal of Molecular Sciences. 2011;12(8):4896-4908. doi:10.3390/ijms12084896
  5. Zhang J, Oxinos G, Maher JH. The effect of fruit and vegetable powder mix on hypertensive subjects: A pilot study. Journal of Chiropractic Medicine. 2009;8(3):101-106. doi:10.1016/j.jcm.2008.09.004 

Haley Hughes MS, RDN, CDCES, Certified Intuitive Eating Counselor 

Katie Whitson Dietetic Intern, MS Human Nutrition and Dietetics, BS Exercise Science

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