US health authorities issue warning against inhalable caffeine product, citing mislabeling and safety concerns.
"The Food and Drug Administration reviewed your website at www.aeroshots.com in February 2012 and has determined that the product AeroShot is misbranded," said the letter. "We also have safety questions about the product."
Because it is considered a dietary supplement, the lipstick-sized product did not have to gain FDA approval to hit the market. It is currently for sale in parts of the United States and France.
The FDA said the product's label "suggests in several places that AeroShot should be inhaled," raising concerns because little research has been done to assess the safety of inhaling caffeine into the lungs.
The product label also "states that AeroShot is 'not intended for people under 12' ... This suggests that the product is suitable for children 12 and over," the letter added, requesting data to back up its safety in youths.
US company Breathable Foods, which makes AeroShot, issued a statement saying that labeling changes are under way to make sure consumers know the product is for ingestion, not inhalation.
"AeroShot delivers a mix of B vitamins and caffeine to the mouth for ingestion and is not 'inhaled' into the lungs," the company's chief executive Tom Hadfield said in a statement.
"AeroShot is not recommended or marketed to persons under 18 or for use with alcohol."
The product was launched in Boston and New York earlier this year after first being introduced in Paris.
Its marketing materials claim to deliver as much caffeine as a cup of coffee along with "B vitamins in a fine powder that is dissolved quickly in the mouth and immediately starts working."