The MonaVie Original juice, which has a purple label, is the original 19 fruit blend. MonaVie Active, which has a green label, has the same blend of fruits as MonaVie Original, but with the addition of liquid glucosamine and omega 3, 6, and 9 fatty acids. Glucosamine may be helpful for maintaining healthy joints*.

* The United States FDA has not reviewed these statements. Glucosamine has not been shown to treat any disease.

An article in the American Journal of Health-System Pharmacy (Vol. 67, page 107-108, 1/15/2010), claims a Potential interaction between MonaVie Active and Warfarin (Katcher and Leung). To MonaVie’s credit this list this in their product FAQ, but they downplay it significantly:

“MonaVie Original and MonaVie Active are very safe to consume. Some prescription medicines, however, are known to interact with foods. Some food/nutrient interactions you should be aware of when taking MonaVie include vitamin K with blood thinners or anti-coagulants (e.g., Coumadin®), and potassium with blood pressure (e.g., metoprolol and propranolol) and ACE inhibitor medications (e.g., captopril).”

The article cites not just the Vitamin K but says, “The combination [Warfarin and MonaVie Active] may theoretically be problematic because of the ingredients in MonaVie: vitamin K, glucosamine, and esterified fatty acids.”

For those not familiar with the brand name Coumadin®, it is often better known as the generic medication Warfarin (the study’s warning).

The study goes on to note that the recommended dietary allowance of vitamin K for Warfarin patience is between 65-80 µg daily… citing this article of vitamin K and Warfarin.

The Katcher and Leung’s research article then notes that, “The recommended intake of MonaVie Active is 30mL twice daily, which would provide about 16-25 µg of vitamin K.” The researchers actually made a mistake in not knowing MonaVie’s recommended intake. It’s not surprising because MonaVie’s serving size is 1 ounce (30mL), but they recommend two servings in the morning and two at night. Thus, a person following recommendations would intake about 32-50 µg of vitamin K daily just from the four ounces of MonaVie.

This is when things get a little interesting. Katcher and Leung looked at glucosamine and found a couple of studies about its interaction with Warfarin. You can read those here and here. Katcher and Leung said, “These sources suggest that the use of glucosamine products over a minimum of three weeks can enhance warfarin effects as manifested by prolonged bleeding times or bleeding complications.”

Lastly, the researchers make note of omega-3 fatty acids and it’s possible interaction with warfarin. They cited three article including this one.

The researchers say that due to these three factors, “[patients] should be instructed to inform their health care providers when considering using MonaVie Active… In patients taking the combination, frequent monitoring of INRs and adverse events may be warranted, and adjustment of the warfarin dosage may be needed.” Of course this suggestion is based on a recommendation that is only half of what MonaVie recommends. One has to wonder what the researchers would conclude if they knew it was twice what they thought.

It sounds to me that MonaVie’s statement of “MonaVie Active [is] very safe to consume”, is quite a stretch. They should probably play it safe and change their website to recommend that no one on Warfarin/Coumadmin consume the product at all. I don’t see why a consumer who is on warfarin/Coumadin would spend a lot of money on this product especially when it lacks nutrition.