Like pretty much everyone else, drink companies are jumping on the neuroscience bandwagon. These widely available “brain branded” beverages make promises that should raise any skeptic’s eyebrows. Today I want to focus on NeuroSonic, which its manufacturers claim is carefully designed to “deliver sustained focus and revitalized energy”.

The curvy, colorful bottle depicts a human head with a sciencey waveform running through it, the strapline “mental performance in every bottle”, and on the back, the promise that you will “stay energized, focused, alert … with modern science’s greatest blend of natural mental performance enhancers. Get smart, DRINK NEURO.”

Founded by Bosnian émigré Sanela Diana Jenkins, NeuroSonic is just one of a portfolio of brain drinks offered by her company Neuro, with others promising to boost sleep, relaxation and other states of mind.

NeuroSonic’s “proprietary blend” includes caffeine and l-theanine (an amino acid found in green tea). The good news, for NeuroSonic drinkers at least, is that several studies suggest that a combination of caffeine and l-theanine can have beneficial mental effects, such as improving the ability to switch between tasks, speeding up anticipatory shifts of attention, and increasing feelings of alertness.

However, these studies are of variable quality (for example, not all of them feature a placebo control condition), and perhaps most importantly, they don’t tell us about the effects of NeuroSonic’s specific mix and quantities of ingredients.

Going to the “Science” page of the Neuro website doesn’t help much. “Our team of drink scientists excels at identifying real peoples’ [sic] daily needs and sourcing the best ingredients from around the world to help solve their problems” is as detailed as it gets. There is a promise of more “facts and information” to come, but seeing as the company launched in 2008, I wouldn’t hold your breath. Neuro can get away with this vagueness because it’s only regulated as a food and drink, not as a medicine.

Three years ago, science writer Carl Zimmer noted that there were no trials to support the claims of brain-branded tricks, so he decided to conduct some self-experimentation to see if NeuroSonic and similar products boosted his own brain power. Apart from a coffee-like buzz (no surprise given that most of these drinks contain caffeine), Zimmer was left disappointed: “I wait for genius to hit me. I feel no surge of brilliance. My writing dribbles on,” he said.

The research situation hasn’t changed much. If you perform a Google Scholar search for NeuroSonic, you’ll uncover just one relevant study, which was published last year (pdf). It was actually conducted by six neuroscience students at MSU Denver, and it’s a neat piece of work, albeit that the sample size is very small. Kudos to two of the students, who presented their findings at the annual Society For Neuroscience conference in 2013.

The students gave half their 35 participants (average age 24; 27 men) a cup of NeuroSonic (roughly equivalent to one bottle); the other half had a placebo drink designed to taste and look similar. The placebo was a concoction of coconut-pineapple flavored water and strawberry-flavored vitamin supplement. Crucially, the placebo had none of the psycho-active ingredients of NeuroSonic, and no-one was able to identify which drink was which based on appearance or taste.

After a 20-minute wait to allow the NeuroSonic drink to exert its claimed effects, the participants engaged in a battery of six cognitive tests. On reasoning ability, visual-spatial memory, reaction time, control of one’s own brain waves, and executive function (the ability to ignore irrelevant information), there were no differences in performance between the two groups. However, on short-term memory – measured via the ability to recall lists of numbers – the placebo group actually out-performed the NeuroSonic group.

The results really couldn’t be much worse for a drink with a brain logo that claims to be specially formulated to boost your focus and concentration. The investigating team led by Charles Walters concluded that they “cannot recommend NeuroSonic as a cognitive enhancer for their fellow college students.”

Why did this study fail to find any benefits of NeuroSonic when the wider research literature suggests the combination of caffeine and l-theanine can boost mental performance? The researchers note that the quantities of l-theanine in NeuroSonic are lower than was used in that earlier research, and the quantities of caffeine higher. The detriment to short-term memory may be something to do with the participants over-doing their caffeine levels. Participants were asked to abstain from caffeine before the study, but this wasn’t regulated by the researchers. Many NeuroSonic drinkers are likely to also drink tea and coffee, so if this is the source of the detriment, it could well be relevant to real life consumers.

This is by no means the final word on drinks designed to boost your mental prowess. But this study is one of the few pieces of genuine evidence we have to go on. The hi-jacking of neuroscience to sell all manner of products (including music apps) and professional services (such as “neuroleadership”) is a bit annoying when it’s gratuitous and unsupported by proper evidence – in this case trials to show that the drink does what it claims to do.

But there’s at least one good news story here. You get the sense from this research paper that the students not only did a great job, but enjoyed themselves too as they discovered the joy of science. As the study concludes: “Although the authors cannot recommend NeuroSonic as a means of improving cognitive function, we do recommend adopting this class project model as a way of involving undergrads in neuroscience research.”

Actually maybe there’s a second positive angle here. Looking at the website for Neuro’s founder, she says she’s donated millions of dollars to international humanitarian causes. If that’s where the proceeds from NeuroSonic sales are truly going, who cares if the drink doesn’t make you super smart?