10 New and Surprising Facts About Alpha-Gal Syndrome

July 2022   Linda Armstrong  |  ✓  Medically reviewed by: Fabio Iachetti, MD; Eva Södergren, PhD, MSc

Fabio Iachetti is a licensed physician with more than 15 years of diverse experience in several disease areas such as allergy, CV, pain, GI, rheumatology, urology, and diabetology. He is a Senior Medical Manager for Allergy in ImmunoDiagnostics Global Medical Affairs at Thermo Fisher Scientific. A nutritionist by training, Eva Södergren now works as a Senior Scientific Advisor for Allergy on the Medical and Scientific Affairs team for Thermo Fisher Scientific’s ImmunoDiagnostics division.

Alpha-Gal Syndrome is just plain weird. And the more we learn about it, the stranger it seems to get. Also known as red meat allergy and tick-bite allergy, the syndrome is an allergic reaction to alpha-Gal, which is a sugar molecule found in mammal meat such as beef, pork, venison, and more.1-2 But this reaction actually begins with a bite from a tick (or possibly a chigger).2-3

It works like this: The tick (or chigger) feasts on a mammal such as a deer, and in doing so, it ingests alpha-Gal. If it bites a human, it can transmit alpha-Gal into the person’s blood stream.2-3 In some people, this triggers an immune response when the person later eats mammalian meat, which can cause mild to severe and even life-threatening symptoms.2

So yeah, the whole thing is pretty odd, right? But what’s really strange is when people experience these symptoms, which can include hives, sneezing, stomach pain, diarrhea, vomiting, nausea, and anaphylaxis, among many others.2

Rather than happening soon after eating (as is the case with many food-related allergies), Alpha-Gal Syndrome symptoms typically don’t occur for three to six hours after eating red meat or other mammal-related products.2 While symptoms can occur any time of day, many patients are woken from sleep thanks to symptoms caused by the meat they ate hours earlier.4 Therefore, this delayed response may make it difficult to connect your symptoms to something you ate.

Along with being pretty peculiar, Alpha-Gal Syndrome is also relatively unknown. In fact, it wasn’t reported until the late 2000s.5 Therefore, chances are that some people including healthcare providers still aren’t familiar with it. Thus, diagnosis can be tricky.6

Nevertheless, the number of patients continue to rise, and scientific research on this novel but serious condition continues. And as new information comes out, the “wacky factor” seems to be multiplying.6

Alpha-Gal Syndrome Facts

Here are 10 newly discovered and/or surprising facts about Alpha-Gal Syndrome, which can aid your understanding and help you and your healthcare provider determine whether you should get tested.

(To learn even more about Alpha-Gal Syndrome, including symptoms, exposure-reduction tactics, and a list of things that may contain alpha-Gal, check out our Alpha-Gal Syndrome fact sheet.)

1. The list of Alpha-Gal Syndrome symptoms seems to be getting longer, and some symptoms can mimic those of Irritable Bowel Syndrome (IBS).7

Symptoms of Alpha-Gal syndrome can run the gamut from an itchy rash and hives to diarrhea and anaphylaxis.6 In fact, anaphylaxis occurs in up to 60 percent of people with the syndrome.8 However, according to survey results presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting, some Alpha-Gal Syndrome patients have a wide range of seemingly new symptoms, such as those involving the cardiovascular, emotional, nervous, and motor systems. In particular, patients in the survey reported a wide range of mental health issues, such as anxiety, depression, fatigue, poor memory, irritability, sleep disturbances, etc.9

Additionally, alpha-Gal symptoms may closely resemble those of IBS. According to a 2021 study in the Journal of Gastroenterology, some people with Alpha-Gal Syndrome only have gastrointestinal symptoms, such as abdominal pain, nausea, and diarrhea. Many of these symptoms overlap with IBS, and 56 percent of patients in this study met the criteria for diarrhea-predominant IBS.7

Based on this study and the fact that some healthcare providers aren’t familiar with Alpha-Gal Syndrome, it stands to reason that symptoms of alpha-Gal Syndrome can be confused with those of IBS.7 Translation: Your tummy troubles could be caused by a tick-related ailment rather than IBS.

One way to know for sure is to ask your healthcare provider for a specific IgE blood test or more specifically, a component blood test. (More on that later.) Together with your medical history and a physical exam, blood testing can help your provider home in on a diagnosis. 

2. For the majority of patients in one study, it took seven years to obtain an Alpha-Gal Syndrome diagnosis.10

While info on Alpha-Gal Syndrome is offered by many medical-information sources, such as the Centers for Disease Control and Prevention (CDC) and the Asia Pacific Association of Allergy, Asthma and Clinical Immunology, the condition is still relatively unknown.1,5,10 Not surprisingly, then, one study revealed that almost 80 percent of its patient participants struggled to find a diagnosis for more than seven years.10 (That’s 2,555 days of suffering, and there’s nothing fun or funky about that.)

What’s more, medical literature reveals that in trying to determine the cause of their ailments, some patients underwent exploratory surgery, removal of their gallbladder or appendix, and partial removal of the pancreas before they finally received an Alpha-Gal Syndrome diagnosis.6 And according to a 2017 paper, patients are more likely to discover alpha-Gal online, on the radio, or through personal connections than by visiting the emergency room due to anaphylaxis.10

These stats are particularly troubling because a simple blood test along with a medical history and physical exam can help a healthcare provider diagnose Alpha-Gal Syndrome. In fact, a single visit with your healthcare provider and a blood draw could help save you not only a boatload of time and money otherwise spent on specialists and unnecessary tests but also a mountain of misery.

3. Skin-prick tests (SPTs) aren’t effective for alpha-Gal, and blood testing is paramount.11

Given the time and money that can be involved in securing a diagnosis, testing for Alpha-Gal Syndrome is critical. There is no explicit Alpha-Gal Syndrome treatment, so it’s vital to receive a proper diagnosis to know what products and foods to avoid. However, you need to get the right test straight out of the gate, and a skin-prick test (SPT) probably isn’t the way to go. In fact, SPTs with extracts of pork or beef have been unreliable in detecting alpha-Gal.11

Rather, ask your healthcare provider for a blood test. But instead of a whole allergen blood test, which helps providers rule allergies in or out, a component test for alpha-Gal will help to pinpoint the specific sugar molecule that is causing symptoms. Plus, component testing can sometimes offer providers insight into the severity of an individual’s reactions.

Component testing also may help your healthcare provider distinguish between patients with Pork-Cat Syndrome versus those with Alpha-Gal Syndrome. (No, we didn’t make that up. Read more about Pork-Cat Syndrome in No. 9.)

That said, it may not be enough just to ask for an alpha-Gal test. You need to be very specific to ensure you get the right one. You want an alpha-Gal specific IgE component test. (Additionally, your provider may want to test for beef, pork, lamb, alpha-Gal, total IgE, and tryptase to help develop a clear diagnosis.) And just because a test has alpha-Gal in the name doesn’t mean it’s the right one. The following tests are NOT recommended for specific IgE testing for alpha-Gal: alpha-Galactosidase nor α-Galactosidase A deficiency, both of which are often used to help diagnose Fabry disease (a rare disorder involving fat metabolism).12

4. Across the globe, bites from several types of ticks (and potentially chiggers) can lead to Alpha-Gal Syndrome.3,4,6

Initially, this syndrome was linked to the Lone Star Tick, which is found mostly in the southeastern United States.2 However, Alpha-Gal Syndrome has now been reported on all continents except Antarctica, and at least eight tick species are confirmed or suspected culprits associated with the condition.5

Additionally, at least some tick species have extended beyond their typical home turf. That is, as hosts such as deer move into different territories, so do ticks that hitch a ride on them. So thanks to different patterns of land use, climate change, and increasing deer populations, ticks like the Lone Star Tick have spread. For example, the Lone Star Tick was previously rare in Michigan, but it’s now the third most common tick in the state.4 Plus, a 2022 article in the Toronto Star revealed that the tick is expanding into Canada due to rising temperatures.13

Also note that many tick bites go unnoticed, particularly from “seed” ticks. Although these baby ticks are the size of a poppyseed, they can still transmit alpha-Gal.4 Recent reports also suggest that bites from chiggers, which are microscopic arachnids (like spiders) that can be found worldwide, may also lead to Alpha-Gal Syndrome.3,6,14

And if you want to hear something really weird, consider this: New research has identified cross-reactivity between tick proteins and wasp venom. That means that some people with Alpha-Gal Syndrome may be sensitized to wasp venom.15 Granted, wasp-allergy symptoms may be different than those related to alpha-Gal. But this fact illustrates that some bizarre and currently undiscovered connections may exist between ticks and insects. 

Alpha-Gal Syndrome is transmitted via multiple tick species and has been reported on all continents except Antarctica.5,11

5. Alpha-Gal can hide in some surprising foods, products, and medical items.

Alpha-Gal reactions are typically caused by eating meat and meat products derived from mammals such as cows, pigs, lambs, rabbits, buffalos, bisons, and kangaroos.4 Additionally, since myriad food items contain meat-based ingredients, they may contain alpha-Gal. (Check out our alpha-Gal fact sheet for a fairly extensive list of potential alpha-Gal sources.) However, alpha-Gal can seemingly hide in far less obvious—and kind of astonishing—places.

Take gelatin, for example. It’s typically made of collagen from the skin and/or hooves of large mammals, so it may contain alpha-Gal. Thus, alpha-Gal could be hiding in gummies, marshmallows, and jello, which contain gelatin.11 Gelatin may also be found in catgut sutures, collagen-derived contact lenses, shampoo, and some tattoo ink.16-17

And if that’s not weird enough, alpha-Gal may be found in various vaccines, antivenom, and medical tablets (e.g., acetaminophen, oxycodone, lisinopril, and oxycontin), and in cow and pig heart valves, which are sometimes transplanted into humans.11

What’s more, some ingredients made from red algae, such as carrageenan, also may contain a type of alpha-Gal. Carrageenan is sometimes used in beer, condiments, infant formulas, salad dressings, and much more.18 So avoiding alpha-Gal isn’t as easy as simply steering clear of burgers and hot dogs.

Higher Risk

Lower Risk


Medications / Biologic Therapies

Beef, pork,
lamb, innards


Gelatin-containing foods


Gelatin plasma expanders

Anti venom (e.g., CroFab)

Bovine/porcine heart valves

Gelatin-containing vaccines (e.g., Zostavax, MMR)

Pancreatic enzyme replacement (e.g., pancrelipase)



Some triggers are more likely to cause a reaction than others.11

6. A cancer-related drug trial led to the discovery of Alpha-Gal Syndrome.4

Alpha-Gal Syndrome was discovered via drug trials for cetuximab, which is an antibody treatment aimed at colorectal cancer and cancer of the head and neck that contains alpha-Gal. A number of patients enrolled in the clinical trials developed anaphylaxis or hives after the first dose of cetuximab. This mysterious reaction led to further investigation and later to identification of the syndrome in the mid 2000s.4

7. Some people could develop symptoms from not only eating meat but also inhaling fumes from meat being cooked.6

Similar to some individuals with a shellfish allergy, people sensitized to alpha-Gal have also reported symptoms after inhaling fumes of mammalian meat being cooked.6,19 That is, in addition to developing symptoms after eating meat, some people have symptoms after inhaling meat fumes. Bonkers, right?

8. Exercise, alcohol, recent tick bites, and nonsteroidal anti-inflammatory drugs (NSAIDs) may increase risk and/or severity.11,20

For patients with Alpha-Gal Syndrome, there are several co-factors that may further increase the risk for a reaction or the severity of symptoms upon exposure to alpha-Gal. These risk factors include atopy (i.e., a genetic tendency to develop allergic diseases), alcohol consumption, exercise, age, and use of medications.20 Other factors that may increase risk include the use of nonsteroidal anti-inflammatory drugs (NSAIDs), which include aspirin (e.g., Bayer), ibuprofen (e.g. Advil), naproxen (e.g., Aleve), and celecoxib (Celebrex).11 The sources of this information failed to provide further details about how, exactly, these aspects affect risk. But this is just one of many areas of this strange syndrome that need further research.

Similarly, while a single tick bite can kick off this syndrome, additional bites can increase a person’s sensitivity to alpha-Gal.6 Thankfully, the opposite is true. According to information from the Mayo Clinic, symptoms may lessen or even disappear over time if sensitized individuals don’t receive additional bites from ticks carrying alpha-Gal.21

9. While it sounds totally made up, Pork-Cat Syndrome is real and sometimes confused with Alpha-Gal Syndrome.22

Speaking of wacky syndromes: Pork-Cat Syndrome is a rare allergic reaction to a protein that’s found in both cat dander and pork.22 This is actually a type of cross-reactivity, which is when the body's immune system identifies the proteins in one substance (e.g., pollen) and the proteins in another (e.g., a fruit or vegetable) as being similar.23 When the person contacts either one, the immune system may create allergy-like symptoms.

Symptoms of Pork-Cat Syndrome vary from hives to anaphylaxis, which means some symptoms overlap with Alpha-Gal Syndrome.22 Plus, since both conditions may involve reactions to pork, misdiagnoses of these conditions are possible. If you think you have either of these pork-related problems, ask your healthcare provider for a component blood test to home in on your pork peculiarities. 

10. Alpha-Gal-free pigs are totally a thing.24

Near the top of the weird-facts list are GalSafe pigs, which according to a recent article in Allergic Living are a new breed of pigs that have been genomically altered to eliminate alpha-Gal. This doesn’t simply mean that those suffering from the syndrome may be able to eat pork chops and bacon once again. It also means that since these pigs might be used for other purposes, those end products could be available to those with Alpha-Gal Syndrome in the future.24

For example, using GalSafe pigs instead of traditional porkers to make medicines and organ and tissue transplants might theoretically make them alpha-Gal free. Additionally, if manufacturers some day opt for GalSafe pig products to make things such as gelatin, medications, and more, those items may be safe for those with Alpha-Gal Syndrome.24

Do you have Alpha-Gal Syndrome?

In terms of medical conditions, Alpha-Gal Syndrome is about as kooky as they come. But in reality, it’s no laughing matter, particularly if you have symptoms.

Jokes aside, the best way to determine if you’ve developed Alpha-Gal Syndrome is to talk to your healthcare provider and request a special type of blood test: an alpha-Gal specific IgE component test. Almost any healthcare provider can order this test for you. 

Before your visit, complete our symptom tracker, which will generate a comprehensive symptom profile you can review with your healthcare provider to decide if a specific IgE blood test is right for you.

Finally, bone up on additional allergy info in our Living with Allergies section and via our Allergen Fact Sheets. And follow us on Facebook, Instagram, and YouTube to stay up to date on the latest info.

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1. Alpha-gal Allergy [Internet]. Centers for Disease Control and Prevention. Centers for Disease Control and Prevention; 2019; 2020 Oct 6. Available from: https://www.cdc.gov/ticks/alpha-gal/index.html.

2. Mayo Clinic [Internet]. Rochester, MN: Mayo Foundation for Medical Education and Research; 2020 Nov 19. Available from: https://www.mayoclinic.org/diseases-conditions/alpha-gal-syndrome/symptoms-causes/syc-20428608.

3. Yale Scientific Magazine [Internet]. New Haven, CT; 2019 Jan 22. Available from: https://www.yalescientific.org/2019/01/chigger-bites-linked-to-red-meat-allergy.

4. Houchens N, Hartley S, Commins SP, Claar D, Saint S. Hunting for a Diagnosis. N Engl J Med. 2021 Feb 4;384(5):462-467. doi: 10.1056/NEJMcps2017588. PMID: 33534979. Available from: https://www.nejm.org/doi/full/10.1056/NEJMcps2017588.

5. Kwak M, Somerville C, van Nunen S. A novel Australian tick Ixodes (Endopalpiger) australiensis inducing mammalian meat allergy after tick bite. Asia Pac Allergy. 2018 Jul 26;8(3):e31. doi: 10.5415/apallergy.2018.8.e31. PMID: 30079309; PMCID: PMC6073180.

6. Commins SP. Diagnosis & management of alpha-gal syndrome: lessons from 2,500 patients. Expert Rev Clin Immunol. 2020 Jul;16(7):667-677. doi: 10.1080/1744666X.2020.1782745. Epub 2020 Jul 8. PMID: 32571129; PMCID: PMC8344025. Available from: https://www.tandfonline.com/doi/abs/10.1080/1744666X.2020.1782745?journalCode=ierm20.

7. Croglio MP, Commins SP, McGill SK. Isolated Gastrointestinal Alpha-gal Meat Allergy Is a Cause for Gastrointestinal Distress Without Anaphylaxis. Gastroenterology. 2021 May;160(6):2178-2180.e1. doi: 10.1053/j.gastro.2021.01.218. Epub 2021 Jan 29. PMID: 33524403. Available from: https://www.clinicalkey.com/#!/content/playContent/1-s2.0-S0016508521003243?returnurl=https:%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0016508521003243%3Fshowall%3Dtrue&referrer=https:%2F%2Fpubmed.ncbi.nlm.nih.gov%2F.

8. Van Nunen S. Galactose-alpha-1, 3-galactose, mammalian meat and anaphylaxis: a world- wide phenomenon? Curr Treat Options Allergy. 2014;1(3):262-77. Available from: https://link.springer.com/content/pdf/10.1007/s40521-014-0022-0.pdf.

9. Healio 1 [Internet]. “Patients with alpha-gal syndrome report ‘wide range’ of previously undocumented symptoms.” 2022 March 1. Available from: https://www.healio.com/news/allergy-asthma/20220301/patients-with-alphagal-syndrome-report-wide-range-of-previously-undocumented-symptoms.

10. Flaherty MG, Kaplan SJ, Jerath MR. Diagnosis of Life-Threatening Alpha-Gal Food Allergy Appears to Be Patient Driven. J Prim Care Community Health. 2017 Oct;8(4):345-348. doi: 10.1177/2150131917705714. Epub 2017 Apr 27. PMID: 28447914; PMCID: PMC5932728. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5932728.

11. Platts-Mills TAE, Li RC, Keshavarz B, Smith AR, Wilson JM. Diagnosis and Management of Patients with the α-Gal Syndrome. J Allergy Clin Immunol Pract. 2020 Jan;8(1):15-23.e1. doi: 10.1016/j.jaip.2019.09.017. Epub 2019 Sep 28. PMID: 31568928; PMCID: PMC6980324. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6980324/pdf/nihms-1060828.pdf.

12. Alpha-gal Information [Internet]. Alpha-gal Syndrome Awareness Campaign; accessed May 2022. Available from: https://alphagalinformation.org/diagnosis-and-testing.

13. Toronto Star [Internet]. “’I felt like I was going to die’: Ticks that cause red-meat allergy are in Canada.” 2022 May 24. Available from: https://www.thestar.com/news/canada/2022/05/20/i-felt-like-i-was-going-to-die-ticks-that-cause-red-meat-allergy-are-in-canada.html.

14. American Osteopathic College of Dermatology [Internet]. Kirksville, MO. Accessed May 2022. Available from:


15. Healio 2 [Internet]. “Patients with alpha-gal syndrome from tick bites may also be sensitized to wasp venom.” 2022 April 25. Available from: https://www.healio.com/news/allergy-asthma/20220425/patients-with-alphagal-syndrome-from-tick-bites-may-also-be-sensitized-to-wasp-venom#:~:text=New%20research%20identified%20cross%2Dreactivity,venom%2C%20according%20to%20study%20results.

16. Peta.org [Internet]. Norfolk, VA: People for the Ethical Treatment of Animals. Accessed May 2022. Available from: https://www.peta.org/about-peta/faq/tattoo-ink-vegan.

17. Mullins RJ, James H, Platts-Mills TA, Commins S. The relationship between red meat allergy and sensitization to gelatin and galactose-alpha-1,3-galactose. J Allergy Clin Immunol. 2012 May;129(5):1334-42. Available from. https://www.jacionline.org/action/showPdf?pii=S0091-6749%2812%2900368-5.

18. Alpha-gal Information 2 [Internet]. Alpha-gal Syndrome Awareness Campaign; accessed May 2022. Available from: https://alphagalinformation.org/carrageenan/#:~:text=References-,Overview,reacting%20to%20carrageenan%20(2).

19. The Anaphylaxis Campaign [Internet]. Farnborough, UK: The Anaphylaxis Campaign; 2019 Sep. Available from: https://www.anaphylaxis.org.uk/wp-content/uploads/2019/09/Shellfish-Sep-2019.pdf.

20. De la Fuente J, Pacheco I, Villar M, Cabezas-Cruz A. The alpha-Gal syndrome: new insights into the tick-host conflict and cooperation. Parasite Vectors. 2019 Apr 3;12(1):154. doi: 10.1186/s13071-019-3413-z. PMID: 30944017; PMCID: PMC6448316.Available from: https://parasitesandvectors.biomedcentral.com/track/pdf/10.1186/s13071-019-3413-z.pdf.

21. Mayo Clinic 2 [Internet]. Rochester, MN: Mayo Foundation for Medical Education and Research; 2020 Nov 19. Available from: https://www.mayoclinic.org/diseases-conditions/alpha-gal-syndrome/diagnosis-treatment/drc-20428705.

22. Kim, Cheon et al. “Recurrent urticaria caused by specific cat serum albumin IgE cross-reacting with pork serum albumin.” Clinical and experimental pediatrics vol. 63,11 (2020): 451-453. doi:10.3345/cep.2019.01725. Available from: chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7642134/pdf/cep-2019-01725.pdf.

23. EAACI, et al. Molecular allergology user’s guide. Zurich, Switzerland: European Academy of Allergy and Clinical Immunology; 2016. p.16. Available from: http://www.eaaci.org/documents/Molecular_Allergology-web.pdf.

24. GalSafe Pigs – Allergic Living [Internet]. “FDA Approves ‘GalSafe’ Pigs for Food, Medicine for Alpha-Gal Allergy.” 2020 Dec 17. Available from: https://www.allergicliving.com/2020/12/17/fda-approves-galsafe-pigs-for-food-medicine-for-alpha-gal-allergy/#:~:text=The%20U.S.%20Food%20and%20Drug,pigs%2C%20licensed%20to%20Revivicor%20Inc.