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Statement on Swine Flu and Nature-Throid/Westhroid by
RLC Labs


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Swine Flu and Pork-derived
Desiccated Thyroid Products:
Is there Reason for Concern?

Dr. John C. Lowe, Editor-in-Chief

April 27, 2009

In the last several days, we have been deluged by emails at and The authors of the emails are concerned over a possible relationship between the virus causing current cases of swine flu and pork-derived desiccated thyroid products. In the U.S. and most other countries, those products are Nature-Throid, Westhroid, and Armour Thyroid.

Typical of the inquiries I've received is this one by someone name Maryann: "I heard on T.V. last night that people are dying from swine flu and that the government is concerned about a pandemic. I take Armour Thyroid and I know that it comes from pigs. I thought about changing to Nature-Throid or Westhroid, but then I read online that they also come from pigs. Do you think taking these products is risky because of the swine flu?"

I replied to the women's question as I have to scores of others. Here, I expand on what I've written to them.

I regret that many hypothyroid patients are concerned about the swine flu in relation to Nature-Throid, Westhroid, and Armour. Unfortunately, the brevity of television news reports too often provokes unnecessary concerns. I've seen several television reports about the recent cases of swine flu, and I clearly see that the ten-second coverage could leave many viewers wondering whether they should abstain from consuming any pork product.

However, I don't believe that abstaining from pork products is necessary to avoid this version of swine flu. Nor do I believe that patients who use porcine-derived desiccated thyroid products risk contracting swine flu.

The New Virus and Swine Flu. We can consider the flu that some people recently developed as a type of swine flu. But we could also consider it a type of bird flu, and a type of human flu. The Centers for Disease Control (CDC) report that the virus, dubbed "swine influenza A (H1N1)," is a hybrid: it contains genes found in European and Asian swine viruses, but it also contains genes typical of bird and human viruses.
[2] The gene segments are a unique combination that researchers haven't previously found in swine or human influenza viruses.[1]

On April 24, 2009, the CDC published a report on two children in California who developed flu from the virus.
[3] According to the CDC, "Neither child had contact with pigs; the source of the infection is unknown." The CDC also stated, "The lack of known exposure to pigs in the two cases increases the possibility that human-to-human transmission of this new influenza virus has occurred."

After the CDC reported the two California cases, several more U.S. citizens developed flu from the virus. On April 24, 2009, the CDC reported: "No recent exposure to pigs has been identified for any of the seven patients. Close contacts of all patients are being investigated to determine whether person-to-person spread has occurred."

This morning, I talked with Dai Jinn, Chief Science Officer of RLC Labs, manufacturer of Nature-Thyroid. Dai told me that he has been closely monitoring information on the virus. "In my reading and discussion," he said, "the very last concern I had regarding H1N1 is any transmission within our food supply, which would include pork-based thyroid medication. Although the origin hasn't been confirmed as to the recent outbreak, we do know that this virus has been identified and the new strain is an amalgam. It is a virus, and the way viruses commonly spread is by airborne sources."

Concerning Nature-Throid and other pork-derived products, Dai was clear: "I think it is very important to acknowledge the fact that no cases have been reported from anyone having ingested any pork-based products in the history of this virus."

Dai concluded with a statement that I believe is extremely important for those concerned about pork-derived thyroid products. To me, his statement is all the more important in that it comes from the preeminent scientist in the field of desiccated thyroid formulation and manufacturing: "Our current supply of porcine thyroid is from a  supplier that has no known cases (origin) of swine flu." He added, "I also don't believe that the virus can survive the purification and desiccation process and be viable at the end 'product' stage. I do have concerns about a pandemic, but not due to the spread of the virus by oral consumption of pork-based food and thyroid products."

Exposure to Pigs. In an editorial note in its April 24 report,
[4] the CDC wrote: "Before the cases described in this ongoing investigation, recent cases of swine influenza in humans reported to the CDC occurred in persons who either had exposure to pigs or to a family member with exposure to pigs.";

When referring to "exposure to pigs," however, the CDC did not refer to infected humans having consumed pork products. Instead, they referred to people exposed to live pigs. For example, Karen Kaplan, a writer for the Los Angeles Times, after interviewing a CDC virus scientist, wrote: "In 1988, a healthy 32-year-old women who visited a pig exhibit at a county fair came down with pneumonia and died eight days later. Epidemiologists tested the exhibitors and found that 76% of them had swine flu antibodies, a sign that their immune systems had tangled with the virus, according to the CDC."

The April 24, 2009 CDC report continued:
[4] "Transmission of swine influenza viruses between persons with no pig exposure has been described previously, but that transmission has been limited. The lack of a known history of pig exposure for any of the patients in the current cases indicates that they acquired infection through contact with other infected persons."

For those taking Nature-Throid or similar products, one point about the virus and the flu it induces is worth emphasizing: researchers have not reported finding this particular virus in pigs, and no pigs have been reported to have influenza A (H1N1)-induced flu.
[2] If it turns out to be true that this new virus doesn't infect pigs, then no one is likely to ingest the virus in their pork-derived desiccated thyroid. But even if some pigs become infected, it's important to bear in mind what RLC Labs' Chief Science Officer, Dai Jinn, told me: the virus wouldn't survive the purification and desiccation process and be active in the final thyroid hormone product. To me, it seems unlikely, then, that hypothyroid patients should fear contracting the virus and developing swine flu from Nature-Thyroid, Westhroid, or Armour Thyroid.

To minimize the chances of contracting the virus, the CDC has not recommended that we cease to consume pork products. It has, however, recommended washing our fingers and hands often, using alcohol-based hand-cleaning solutions, and keeping our fingers away from our mouth, nose, and eyes. And of particular importance, the CDC advises us to avoid person-to-person transmission of the virus. They caution, for example, to stay away from people who are coughing or sneezing.

To me, this makes flying in jetliners—which circulate the cabin air over-and-over again as we fly—a far greater risk for contracting the new virus than is ingesting pork-derived desiccated thyroid. Robert J. Boser, Editor-in-Chief, AirlineSafety.Com, denies that we have an exceptional likelihood of contracting airborne microbes on airliners.[6] Somehow he doesn't understand the increased risk of contracting airborne viruses when the same virus-laden air is brought to our mouths and noses again-and-again, often for hours, during flights. I don't find his anemic and defensive attempt to lull us into comfort reassuring. The respiratory infections my friends, relatives, and I have gotten immediately after riding these flying petri dishes proves to me that Boser is wrong. If the airlines were seriously concerned about our respiratory safety, they would at least hand us disposable facemasks as we board their planes. But I digress . . .

RLC Labs is preparing a formal press release about this issue. We will post the release at Thyroid Science as soon as we receive it. If you want to talk with RLC Labs personnel about this issue, you can reach them at their toll-free number: 1-877-797-7997.


1. Investigation and Interim Recommendations: Swine Influenza (H1N1). CDC Health Advisory. April 25, 2009,


3. Centers for Disease Control and Prevention (CDC): Swine Influenza A (H1N1) infection in two children—Southern California, March-April 2009. MMWR Morb Mortal Wkly Rep., 58(15):400-402, 2009.

4. CDC: Update: Swine Influenza A (H1N1) Infections—California and Texas, April 2009. April 24, 2009,

5. Kaplan, K.: Swine flu's next move impossible to predict scientists have yet to figure out how this strain of the influenza virus spreads, or what makes it lethal. It could continue spreading or fizzle out, they say. Los Angeles Times, April 27, 2009.

6. Boser, R.J.: Why Do Airlines Use "Recirculated" Air? Will it make me sick?

A Call for Papers. Thyroid Science is an open-access electronic journal. As, pro forma with new journals, we are calling for manuscript submissions. We welcome any submission, whether a paper or letter, that is earnestly intended to contribute to truth in thyroid science and thyroid clinical practice. In that we are dedicated to such truth, we consider Thyroid Science a stark contrast to most major medical journals todayespecially endocrinology journals. In my judgment, most such journals have been co-opted by corporations and are used as cloaked advertising media. We conceived Thyroid Science as an alternative to those publications. We offer it as a medium of expression for those who want their views publisheduncensoreddespite the views being unfavorable to the financial interests of corporations that financially support the jounals.

Using the electronic format, Thyroid Science will share a benefit with other journals that are now published only electronically. That benefit is speed of publication. We can publish papers as rapidly as the authors and our editors prepare them for publication.

Before submitting a letter or paper, please see our Authors' Guidelines and How to Submit to Thyroid Science. If you would like to communicate with us, please write to us at

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