What Is Alpha-gal Syndrome?

Medically Reviewed by Dany Paul Baby, MD on April 08, 2022

Discovered recently, alpha-gal syndrome is a food allergy to red meat and other animal products made by mammals. Reactions to eating these products can be dangerous or even life-threatening to those with this allergy. Now that this allergy has been identified, a growing number of people are being diagnosed. Here’s what you need to know when it comes to alpha-gal syndrome.

What Is Alpha-gal?

Alpha-gal is a sugar molecule that most mammals have, except for great apes and humans. This means that this molecule is found in red meat that people eat, including:

  • Beef
  • Lamb
  • Pork
  • Venison
  • Rabbit
  • Squirrel
  • Goat
  • Buffalo
  • Horse 

As the alpha-gal molecule is only present in mammals, you won’t find it in other animal proteins like fish or poultry.

In the U.S., people who have alpha-gal syndrome usually get it through a tick bite. The bite transfers the alpha-gal molecule into a person’s body, which may then cause a reaction. The lone star tick is native to the southeast portion of the U.S. and its bite is associated with causing the alpha-gal allergic reaction. Therefore, most people who report alpha-gal syndrome are from this region. Since deer carry the lone star tick, cases are spreading to other regions, including the eastern and south-central U.S. Outside of the United States, alpha-gal syndrome has been reported in parts of Europe, Asia, and Australia and related to bites by other kinds of ticks.

Under normal conditions, eating the alpha-gal molecule in red meat doesn't have any risk for humans. The allergic reaction is triggered when the tick bite releases the molecule directly into your bloodstream. This causes your body to create antibodies to fight off the sugar molecule. The next time that you eat red meat that contains alpha-gal, your body will release histamine, which causes the symptoms of an allergic reaction.

Alpha-gal Syndrome Symptoms

While many allergic reactions happen immediately, the reaction to alpha-gal is delayed. Most people with alpha-gal syndrome won’t have a reaction until up to eight hours after eating food containing alpha-gal, perhaps even a little later. Because the allergic reaction is delayed until much later, it can be hard to pinpoint what’s causing it.

Alpha-gal syndrome symptoms include:

  • Nausea and/or vomiting
  • Rash
  • Hives
  • Diarrhea
  • Cough
  • Heartburn and/or indigestion
  • A painful stomachache
  • Lowering blood pressure
  • Swelling in places like your lips, eyelids, tongue, or throat
  • Feeling faint or dizzy

While symptoms are delayed, they commonly appear around 2 to 6 hours after eating something that contains the alpha-gal molecule. This is the most common timeframe, but symptoms can be delayed for even longer. These symptoms range in severity depending on the person. They can be mild to life-threatening, as with any type of allergic reaction.

People with alpha-gal syndrome may not have a reaction every time they eat red meat. The most severe reaction is called anaphylaxis, which can include a variety of symptoms on the list below. Without treatment, anaphylaxis can be fatal.

Some signs of anaphylaxis include:

  • Rapid heart rate
  • A sudden dramatic drop in blood pressure, also called anaphylactic shock
  • Constriction or swelling in your throat that makes it hard to breathe
  • A feeling of dizziness or lightheadedness that can lead to losing consciousness

Alpha-gal Syndrome Diagnosis and Treatment

Since alpha-gal syndrome is relatively new, not all doctors have experience diagnosing this allergy. In fact, it is often misdiagnosed or not diagnosed at all since the symptoms don’t show up immediately as do other food allergies. Even in regions where alpha-gal syndrome is most common, it is through people advocating for themselves that most cases are diagnosed.

Diagnosis. If you think that you have alpha-gal syndrome, you should talk to your doctor. To begin, your doctor will ask you about your history and then give you a physical exam. Next, a series of blood and skin tests may be ordered to confirm if you have alpha-gal syndrome. A specific blood test measures the levels of a certain kind of immunoglobulin E (IgE) antibody and is usually the key in diagnosing alpha-gal syndrome.

Is alpha-gal syndrome permanent? Currently, there isn’t a cure for alpha-gal syndrome. The FDA hasn’t approved any sort of alpha-gal syndrome treatment yet, either. While that might sound a little scary, you can manage this food allergy with the help of your doctor.

To help manage this type of allergy, your doctor will probably recommend that you stop eating meat from mammals, like the ones mentioned earlier. If you’ve had severe reactions in the past, you might also have to avoid other mammal products, like dairy and gelatin. In this case, you will need to learn to read food labels carefully in order to avoid any mammal products.

As a precaution, your doctor may also write you a prescription to get an epinephrine injector (EpiPen) to carry with you. This is a single-dose medication that is used in case of an emergency if you’re having a bad allergic reaction.


The best way to prevent alpha-gal syndrome is to try and prevent the tick-bites that are known to cause it. Avoid places where ticks live, like areas with high grass and lots of vegetation. If you do need to go into these areas, be sure to wear long sleeves and long pants, and then tuck your pants into your socks so that your ankles aren’t exposed. Wearing a hat and gloves also gives you extra coverage.

Stock up on insect repellent that has a concentration of at least 20% DEET. You can apply it to your skin, avoiding sensitive areas like your eyes, mouth, or hands. You can also spray insect repellent over your clothing. While you are outside or when you come in, be sure to check yourself, children, or pets for ticks on your clothing or skin.

If you’ve been in an area that’s known to have ticks, shower when you come back inside. Scrubbing gently with a washcloth can help remove any ticks that are stuck to your skin since they can attach themselves and stay there for hours to come. If you find a tick on your skin, you should remove it immediately. To do so, gently grab the tick near its head with a pair of tweezers without squeezing it. Slowly pull it out and dispose of it and then apply antiseptic to the tick bite.

Show Sources


Alpha-gal Information: “What Is Alpha-gal Syndrome?”

American Academy of Allergy Asthma & Immunology: “Alpha-gal and Red Meat Allergy.”

Arkansas Department of Health: “Alpha-Gal (Allergy).”

Centers for Disease Control and Prevention: “Alpha-gal Syndrome.” “Alpha-gal Syndrome - Symptoms, Diagnosis & Treatment.”

Mayo Clinic: “Alpha-gal Syndrome.”

Tick-Borne Conditions United: “Alpha-Gal Syndrome.”

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