Authorities to review if "Aeroshot" caffeine inhalers qualify as diet supplements.

A new product on sale in the United States allows people to harness the effects of caffeine without drinking coffee or taking pills.

Breathable Product, as the company is named, has marketed its "Aeroshot" caffeine inhalers as "dietary supplements", meaning they do not require safety approval from the US Food and Drug Administration (FDA).

The FDA is now in the process of reviewing whether or not the inhalers meet legal criteria as diet aids.