For those dreaming of a quick caffeine fix, don’t hold your breath. On Wednesday, March 8, the FDA issued aletter of warningto the makers ofAeroShot, the breathable caffeine inhaler that hit stores in January 2012.

In a letter to Breathable Foods (the makers of Aeroshot), the FDA took issue with a few of the company’s claims. Firstly, the FDA said consumers can’t really inhale the product as the label suggests. The letter also mentioned Aeroshot isn’t proven safe for anyone under 18, even though the product label only warns users under 12. And, while the Breathable Foods website links to articles on using Aeroshot with booze, the FDA said it could be dangerous to combine caffeine and alcohol. Breathable Foods is supposed to send research on the product’s safety to the FDA within 15 days.

Because it’s a dietary supplement, AeroShot didn’t need the FDA’s seal of approval before it arrived on the market. But Senator Charles Schumer recently asked the FDA to review the product’s safety, after earning official party-pooper status in December, when he labeled the product a potential “club drug.” The review would focus on whether the product is safe to use and whether it fits the legal definition of a dietary supplement.

AeroShot, a small plastic inhaler filled with a citrus-flavored kick of caffeine and B vitamins, arrived at stores in New York and Massachusetts just in time for the New Year. Smaller and more portable than a Grande Frappuccino, it goes places a cup of coffee can’t. (Try hitting the ski slope with two poles and coffee in hand.)

And unlike a coffee cup filled with cream and sugar, the AeroShot is naturally calorie-free. But don’t be fooled by this product’s name. It’s not actually possible to inhale the AeroShot’s powder substance — the body digests the powder like any other drink, so the caffeine doesn’t head straight to the brain. As soon as AeroShot turned up on store shelves, some people were hesitant about this caffeine quick fix, questioning the need andsafety of another artificial pick-me-up.

Dr. David Edwards, the Harvard professor who masterminded AeroShot, claims the product is safe. According to Breathable Foods, AeroShot isn’t as dangerous as jitter-inducing energy drinks because it doesn’t contain the same additives.

For those who have already sampled this lipstick-sized inhaler, the results are mixed. Some were less than thrilled about its bitter taste, while others happily discovered a pocket-sized Starbucks. I also had a chance to test it out, and was reminded of an oddly- flavored multivitamin that stayed uncomfortably stuck in my throat. (I still felt pretty sleepy, too.)

Regardless of the results of the FDA’s review, remember the AeroShot isn’t the only zero-calorie solution for a caffeine craving. It’s also possible to spice up coffee with a spoonful of cinnamon. Or perhaps I’ll stick to old standbys to stay awake — like a cup of green tea or (gasp!) a solid night’s sleep.

Shana Lebowitzcontributed reporting.

Photo Courtesy of AeroShot Pure Energy

Article updated March 2012.