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.

Scott – Aspirin is used to treat pains and for head aches some people swear buy it, it doesn’t do a thing for me, I guess I should call everyone who says it works for them a liar making false claims. (source)

#91 – Damian – “There are people who take Tylenol…and it does nothing for them. Then they take Advil and it does wonders…does that make Tylenol a scam?” (source)

#259 – Damian – “…Tylenol doesn’t work for me… Advil does.” (source)

#1237 – MonaVieUser – “If I get a headache with is very rare, Tylenol doesn’t work for me, but I guess it works for some people…” (source)

(Spelling corrected in the above quotes for readability.)

Notice how similar these all sound. It’s almost like a script. In fact, we even have Damian projecting the Tylenol/Advil argument as something that others experience… and then he turns around and says that it doesn’t do anything for him personally. It does sound like someone who confused a script.

Here’s the problem with the argument… Aspirin has been clinically proven. It has treat pains and headaches in billions of cases over dozens of years. I have never met a person who it didn’t help – nor heard of someone it didn’t help (except for MonaVie distributors). I’m sure there might be some out there and these people might be in the 0.001% who are like that. In my opinion, it’s extremely unlikely that they’d all wind up selling MonaVie.

MonaVie has not been clinically proven to even help treat pains or headaches of one person more than a placebo would. Since people spend billions more aspirin than on MonaVie a year, one would think that MonaVie could prove that it helps people with pains and headaches, they would. Then they could put an all-powerful thing on the label saying that it’s been shown to help that medical condition. It would mean 10x more money for MonaVie and their distributors almost overnight. Yet MonaVie can’t put their money into running those tests?

It’s another case where MonaVie distributors are trying to get people to think of MonaVie in a medicine light. In fact, the name MonaVieUser, is another attempt at that. People don’t talk about food and drink as “using it.” One would expect him call himself MonaVieDrinker. It’s a good use of Doublespeak to try to subtly confuse people.

“A placebo is a sham medical intervention. In one common placebo procedure, a patient is given an inert sugar pill, told that it may improve his/her condition, but not told that it is in fact inert. Such an intervention may cause the patient to believe the treatment will change his/her condition; and this belief does indeed sometimes have a therapeutic effect, causing the patient’s condition to improve. This phenomenon is known as the placebo effect.”

I added the bolding myself for emphasis. If the power of positive thinking can have a proven therapeutic effect, it is reasonable to assert that drinkers of MonaVie may be experiencing this. Why might people think MonaVie would improve his/her condition? I can think of three reasons (there may be more):

• Distributors or the Internet say is does – You can search Google and find tons of references of MonaVie being linked to supposedly helping people with autism. These are unverifiable claims that may be added by distributors to help sell their product.
• MonaVie’s serving size is medicine-sized – People are used to taking medicine in doses of 1 ounce or less. People drink juices in serving sizes of 8 ounces or more. MonaVie’s juice is in a 1 ounce serving size increasing it’s similarity to juice. You’ll never hear anyone talk about drinking MonaVie as a thirst-quenching beverage like any other juice.
• Distirbutors use language like “taking” MonaVie – You’ll hear people say all the time that they “take” MonaVie in the morning and night. You “take” pills and medicine – not juice. No one says that they “take” a glass of orange juice at night time. You drink juice. Listen for when people say that they are taking MonaVie and you can spot that they may be subtly trying to trick you (or they are unaware that they’ve been tricked themselves) that it’s medicine.

It’s also worth noting that’s an additional placebo effect here… the Price-Placebo Effect. Scientists have shown that people perceive a product to have more value when they pay more for it. They not only think that, but the product seems to “work” more because of it. In fact, people told they were spending more money for a energy drink actually performed better on mental tasks.

So we see here that there are two reasons why MonaVie may appear to provide some kind of benefit to a person – without physically providing it. Some may say that it’s irrelevant, they just want the benefit. I understand that line of thinking, but realize that placebos can be had cheaply. If you really want the Price-Placebo effect, you should buy your placebos from a friend at a high price and sell him yours at the same high price.

It is well-worth noting that one can’t argue it’s not the placebo effect as it works subconsciously. They simply can’t know what’s in their subconscious as that is the very definition of subconscious. So if someone says that they know their body and MonaVie helped it and it wasn’t the placebo effect (as I’ve seen numerous times), you know that they really don’t understand the placebo effect and how it works.

Frequent commenter, Vogel adds a great point:

“We should also bear in mind that this is not just a typical placebo effect situation, but rather one in which there are tangible rewards for believing that Monavie acts like a drug (e.g., group acceptance, better sales, greater profit) and clear disadvantages to not believing (group ostracism, reduced ability to sell the product convincingly, etc.). In other words, the placebo effect is being strongly coerced.”

Update: Some claim that it’s not possible for a placebo to have the effects that they are seeing on people. Those people would be flat out wrong.

Non-alcoholic beer can make people act drunk

Did you know that the placebo effect can make people act like they are drunk when they haven’t had any alcohol? It’s true… see this Victoria University study. Here are a few quotes:

“We found people who thought they were intoxicated were more suggestible and made worse eyewitnesses compared with those who thought they were sober,” Seema Assefi says.

“In fact the ‘vodka and tonic’ students acted drunk, some even showing physical signs of intoxication,” she adds.

and:

When told, the sober students reacted with disbelief.

“When students were told the true nature of the experiment at the completion of the study, many were amazed that they had only received plain tonic, insisting that they had felt drunk at the time,” she comments.

Dr Garry concludes: “It showed that even thinking you’ve been drinking affects your behaviour.

Clearly it is quite possible that the people making MonaVie testimonies are like the drunken students insisting that they feel something that clearly isn’t there.

There’s also the famous non-alcoholic keg party prank that Princeton pulled that duplicated the effects:

Update : I read an article here that the placebo effect even helps those who know it is a placebo. I’m not sure how that plays into things, I just found it interesting.