Zincs connection to the common cold isnt as wooie as you all might be thinking after this weeks Zicamscepade (cough, sniffle). Though Zicam was marketed as a ‘homeopathic’ remedy, zinc–>common cold connection wasnt established by some naked sweaty white guy pretending he is a Native American deciding that Ayurvedic law dictates ‘colds’ require a ‘hot’ metal like zinc to neutralize viral chi.

Zinc–>common cold was discovered by boring ‘science’ a long time ago. In 1974, Korant et al tested a ton of metals ions at lots of different concentrations to see if they had any effect on cold virus replication– cadmium, calcium, cobalt, copper, magnesium, manganese, mercury, molybdenum, nickle, and zinc.

Zinc is the only one that worked. Turns out it interferes with the cleavage of an essential polyprotein (like how HIV-1 gp160 gets cleaved into gp120 and gp41), interfering with cold virus replication. YAY!

Well, all those experiments were in tissue culture. Know how we kill HIV-1 in tissue culture? Bleach. Tissue culture victories arent always real-world victories.

In 1984, a clinical trial involving zinc salt lozenges showed promise, but later analyses demonstrated that zinc salts did not provide therapeutic concentrations of zinc, so if zinc was ‘working’, it wasnt by the mechanism proposed in 1974.

Around 2000, scientists started publishing the results of their new idea: Maybe the zinc ions are binding to the receptors on the outside of the viruses, preventing them from binding to our receptors, limiting infection? Well, the cold virus replicates in your nose/respiratory tract, so why not just put zinc gel/spray up your nose? Like putting EGCG in condoms, put the drug where the action is.

Some of the nose-zinc trials worked, some didnt– the scientific community was still working out the kinks… too late. Zicam blew through the door in 1999, and was marketed straight to the public. None of that hoity-toity lab learnin for THEM!

Charles Hensley and his colleagues at Gel Tech thought the solution was as plain as, well, the nose on your face. Why not skip the mouth and spritz the zinc directly into the old proboscis? They developed a gel that can do just that and tried it out on 104 volunteers. The results of this study, having been withdrawn once, will probably never be published in a scientific journal. Because Zicam is marketed as a homeopathic remedy, however, the Food and Drug Administration doesn’t require it to undergo rigorous testing.

At this point, the only fair thing to say about Zicam is that its benefits are still not proved. Maybe if I’m desperate, I’ll try it next time I get a telltale tickle in my throat. In the meantime, I hope to sidestep the problem by following the advice of Dr. Jack Gwaltney of the University of Virginia School of Medicine, a top cold researcher. “Wash your hands a lot with soap and water,” he says, because cold viruses like to linger there. Don’t put your fingers in your eyes or nose, as they give easy access to the nasal passages.

Fast forward to 2006.

Results: Coronal sections of the rat ONe and corresponding olfactory bulbs showed consistent cellular and tissue damage of increasing severity that correlated with the duration of treatment with the zinc compound when compared with the control group animals.

Conclusion: The results of this analysis indicate that the repeated oral administration of such zinc-containing compounds have neurotoxic effects on the ONe and to the mitral cells in the olfactory bulbs of treated rats. These findings point toward the need for increased investigation into the potential deleterious effects of zinc-containing compounds to humans as well.

Aaaaand here we are in 2009.

The agency says that since 1999, it has received more than 130 reports of loss of smell associated with Zicam Cold Remedy Nasal Gel; Zicam Cold Remedy Nasal Swabs; and Zicam Cold Remedy Swabs, kids size. The products have been linked to long-lasting or permanent loss of smell called anosmia. In some cases, the loss of smell occurred after the first dose.

So there you have it. The rise and fall of zinc as a cure for the common cold. Decades of work by real scientists has been tarnished in an instant by some money grubbing ‘homeopathic’ businessmen. Zinc didnt deserve to die like this.


  1. #1 Sili
    June 18, 2009

    So you admit that Big Pharma is to blame for this obvious lack of respect for human beings. “No testing”?!! Good Heavens, miss Wotherbottom, I think I have the vapours!

    I pretty much managed to avoid colds this year by following that advice (well, I’m not too good about not touching orifices, but but I did wash my hands religiously and as far as possible to touch doorknobs). Did get a bit of a sore throat over Crimbo – prolly after the trainride.

    I think I once learnt that Zn is part of the first metalloenzyme in the dehydrogenation of alchol. And Molybdenym in the other. We talked about taking Zn supplements to be able to drink more – and Mo to avoid the hangover. Pity to hear that Zn can’t be raised in serum.

  2. #2 Optimus Primate
    June 18, 2009

    You know what the saddest thing about all of this is, for me at least? I have a number of woo-positive friends who are PISSED at the FDA over this whole Zicam brouhaha. They’re convinced it’s all a big conspiracy to “regulate natural remedies” and “take away our freedoms!”

    No joke.

    I honestly don’t think these people would trust any remedy that passed rigorous testing and clinical trials, zinc-based or not.

  3. #3 Roland Branconnier
    June 18, 2009

    And that boys and girls is why the FDA requires that real drugs demonstrate both safety and efficacy.

  4. #4 Joshua Zelinsky
    June 18, 2009

    I suspect that research into this area won’t terminate completely although research may decline for a while. (And the 2006 result you quote shows that there may be serious problems anyways).

  5. #5 flo
    June 18, 2009

    @sili I really think this depends on how you define “big pharma”. I this includes all corporations, even those that only sell natural remedies, then certainly.
    I really don’t know why you think erv is “admitting” anything or why she should have to.
    The biggest problem here is after all the because zinc is seen as “natural” it can be marketed as a homeopathic remedy and does not have to be tested. ( Those rules are not made by “big pharma” but by the gov’t. Though “big homeopathy” would probably throw some major tantrums if anyone thought about changing them.
    through all that keep in mind: The dose makes the poison.
    Also, no industry is w/o fault. I read an interesting article by a major swiss pharma exec a while ago which freely admitted that the industry or at least some in the industry had made mistakes/applied bad ethics in the past, but that happens in every industry, and my scientific knowledge tells me that a sensible use of “big pharma”‘s drugs is much more effective than anything from “big homeopathic”.

  6. #6 W. Kevin Vicklund
    June 18, 2009

    Flo, I believe Sili is acting the Poe in the first sentence – not a serious comment.

  7. #7 Raimund
    June 18, 2009

    I think this merely supports the position that homeopathy stinks and it’s users can’t smell it. But I don’t actually see how zinc has sympathetic magic with the common cold anyway, unless of course you were to snort some powdered ZnO or the like, because you’d almost certainly sneeze, cough and get a runny nose as your body tries to expel the insoluble substance. Of course by that token, maybe pepper is a better fit for a homeopathic cold cure?

  8. #8 Nigel
    June 18, 2009

    In what sense is this homeopathic? I thought the homeopathy involved (1) finding a substance that makes the symptoms worse, and (2) not giving the patient any of it (because you have diluted it until there is none left). This stuff actually does contain zinc, doesn’t it? Does “homeopathic” now mean nothing more than “not tested for either effectiveness or safety”?

  9. #9 cm
    June 19, 2009

    I’m pretty sure olfactory receptor neurons grow back. I guess mitral cells do not, though.

  10. #10 Sandra Porter
    June 19, 2009

    Nicely dissected, ERV! Is there zinc in Airborne? I always find that to be one of funniest OTC cold remedies on the shelf.

  11. #11 Eric Lund
    June 19, 2009

    In what sense is this homeopathic?

    Exaggerated claims of the supplier. That is apparently enough under US law to exempt it from normal FDA regulation, at least until it can be shown to actually hurt people (which is why the FDA can regulate it now).

    Mainstream medical people are upset about this for good reason. What surprises me is that homeopathy advocates are not also upset. Homeopathic remedies are just as effective as placebos, yes, but for the reasons you give, at least you could say that they weren’t harmful, either–which in the early days of homeopathy (mid 19th century) gave it an advantage over the mainstream medical treatments of the time. Now we can’t even count on a homeopathic remedy being harmless.

  12. #12 William Wallace
    June 19, 2009

    And that boys and girls is why the FDA requires that real drugs demonstrate both safety and efficacy.

    Demonstrate? LOL. See Darvon, Fentanyl, Bextra, Vioxx, Thalidomide, etc.

    I am not convinced the victims who lost their sense of smell would have been protected if this had gone through normal processes.

    You cannot conclusively demonstrate safety. In general, whether or not there is a recall is independant of the FDA/homeopathic route. You cannot demonstrate safety before release, and sometimes new information is gathered after a lot of people start taking a new drug.

  13. #13 JD
    June 20, 2009

    I remember being backstage with Leo Kottke when he snorted zinc. I thought it was cocaine at first and said, “what the fuck are you doing?” We all thought it was good for influenza. I think cocaine would have caused less problems.

  14. #14 amphiox
    June 21, 2009

    William Wallace, correct if I am wrong, but I thought Thalidomide was NOT approved in the US by the FDA, and as a result the US was spared the worst of the Thalidomide-related birth defect tragedy that afflicted other countries like Canada.

  15. #15 Sili
    June 21, 2009

    I was indeed trying to mock the inevitable response from the alties: Big Pharma have done proper trials of Zink, ergo zink is baaaaaaaad and it is the fault of Big Pharma that people have now shot their noses to Hell.

    Slightly disturbing how easy I found it to enter their mindset.

  16. #16 Prometheus
    June 22, 2009

    Darvon-carries a black box warning because of recreational abuse and hence is over prescribed under patient pressure. The reported suicides were commensurate with any opoid analgesic abused at the same levels. Chainsaws are dangerous too of you decide to juggle them as opposed to following the directions. Too many chainsaws simultaneously=problems. Example Fails

    Fentanyl-Problems with delivery of an pain killer that is 100 times more powerful than morphine probably should have been expected, but that is bad or insufficient engineering NOT Pharmacology. Example Fails

    Bextra, Vioxx- Cyclooxygenase 2 Inhibitors- cause arrhythmia and liver damage, they also restored movement and alleviated pain that no other option could. In low dosages with monitoring for other variables they could have restored the quality of life to lots of people who were advised of risks but hey, easier to just ban them and hope over the border pill peddlers will be responsible in their dosage calculation and monitoring. Example Fails

    Thalidomide-It has already been pointed out that there was only one U.S. suit against Chemie Grünenthal and the Plaintiff brought the drug with her from Germany. Example Fails

    The Germans charged the board of Grünenthal with manslaughter for circumventing their regulating body.

    I’ve got a friend in Brighton who is a “flipper baby”, WW once again you don’t know what you are talking about.

    P.S. You haven’t lived till you’ve watched a guy do flaming sambuca shots with his feet.

  17. #17 Calli Arcale
    June 22, 2009

    Exaggerated claims of the supplier. That is apparently enough under US law to exempt it from normal FDA regulation, at least until it can be shown to actually hurt people (which is why the FDA can regulate it now).

    This is being covered on some other blogs (Respectful Insolence, Science Based Medicine, etc) and from that, I’ve learned that the FDA exemption is fairly simple as to how a medicine is defined as “homeopathic” — it has to appear in the homeopathic formulary. (There’s an official document maintained by the homeopaths themselves.) Despite it actually contradicting the basic premises of homeopathy, Zicam does meet that definition. The minimum allowed dilution of zinc is 1X — which means, basically, dilute and succuss (a special kind of shaking) once. 1X is a 1:10 ratio. For zinc, that’s a staggeringly high amount, way far above what anybody tested as efficacious against cold viruses. Zicam, according to its manufacturer, is 2X, and therefore meets the definition of homeopathic that binds the FDA. 2X means 1 part per 100. (The dilutions are exponential; one more common homeopathic strength is “30C”, which means one part per 10^60, a truly absurd value.) But if you do the math, 2X zinc is still an awful lot of zinc to shove up your nose.

  18. #18 LightningRose
    June 25, 2009

    For several years I’ve used Cold-Eeze lozenges at the first sign of a cold or sore throat and they seem to help. But I have noticed a bit of temporary numbness in my taste buds.

    It may be a placebo effect, but they’re tasty and do soothe my throat.


New comments have been disabled.