The Molecule of the Week is the active ingredient in Zicam, the nasal gel cold remedy that the FDA warned consumers to stop using this week. What’s the problem? Some users have reported losing their sense of smell after using the gel. On Tuesday, the FDA stepped in and issued a warning letter to Matrixx Initiatives about Zicam:

According to the labeling accompanying the Zicam Cold Remedy intranasal products, each of these products “reduces” the “duration of the common cold” and the “severity of cold symptoms,” including specifically “sore throat • stuffy nose •sneezing • coughing • congestion.” These claims make these products drugs, as defined by section 201(g)(1) of the Federal Food, Drug, and Cosmetic Act (the Act), 21 U.S.C. § 321(g)(1), because they are intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease or to affect the structure or function of the body of man or other animals.

The FDA has urged consumers to stop using zinc gluconate products that involve application inside the nose. Zinc lozenges are not part of the warning. It’s a healthy reminder: just because a remedy is “homeopathic” doesn’t mean that it’s also safe. Chemical activity comes with the molecule itself– it doesn’t matter whether it was made by a living organism or synthesized in a lab.

The molecule itself is interesting– like two sugar-like wings around a central zinc ion. The gluconate “wings” are oxidized forms of the sugar glucose, in case that name looked familiar. Zinc ions bind to electron-rich atoms (like those oxygens) on many types of biological molecules.

I’ll be interested in the follow-up investigation into Zicam and further scientific evidence. I’m not willing to put my sense of smell on the line until researchers know more.

Reuters Health: US tells Zicam maker to stop selling some products