I've always hated Zicam, because of it's ridiculous claim to be a homeopathic remedy, when the mechanism of action of zinc gluconate (the active ingredient) has nothing whatsoever to do with the pseudoscientific principles of homeopathy.

Now the FDA is cracking down, because Zicam may be downright harmful - you could lose your sense of smell because zinc ions applied directly to your nasal epithelia can be toxic.

A PubMed run through the literature on zinc gluconate brings up mixed results. Many studies suggest that, when taken soon after the onset of symptoms, zinc sprays or lozenges can reduce the duration of the common cold. But the meta-reviews of all the evidence to date come to mixed conclusions about how effective this treatment really is. And the evidence that a zinc solution sprayed up your nose can permanently kill your olfactory receptors is growing - it's not completely solid yet, but disturbing enough to suggest that you ought to think twice before risking your sense of smell on a treatment that may not work that well.

The showdown between the FDA and the makers of Zicam raises another issue: should the FDA have the power to recall products? The FDA has issues a warning, but Matrixx (which, because it has labeled Zicam as a non-drug homeopathic remedy could get around FDA requirements for drug safety and efficacy) has not recalled Zicam.

A widely-publicized warning by the FDA is probably as effective as a recall in many cases. I support giving the FDA recall authority, the evidence bar for a recall should be higher than the bar for issuing a 'proceed at your own risk' warning. When the signs are troubling, but more investigation is needed, a warning should suffice; when a product is without question harmful (and the company refuses a voluntary recall), then the FDA should be able to issue its own recall.

In any case, good for the FDA for speaking out on Zicam.