What is Alpha-Gal Syndrome?

Alpha-Gal Syndrome (AGS) is an allergic condition triggered by the bite of a Lone Star tick. It causes allergic reactions to galactose-alpha-1,3-galactose (alpha-gal), a sugar molecule found in most mammals. Symptoms typically appear 3-6 hours after eating red meat, pork, or lamb, and can range from hives to life-threatening anaphylaxis. According to the CDC, over 450,000 Americans may have developed AGS since 2010.

What foods should Alpha-Gal patients avoid?

Alpha-Gal patients must avoid all mammalian meat including beef, pork, lamb, venison, and bison. Many also react to mammalian by-products like gelatin (found in gummy vitamins and gel capsules), dairy products, and ingredients derived from mammals such as lard, tallow, and carrageenan. Safe alternatives include poultry (chicken, turkey, duck), fish, seafood, eggs, and all plant-based foods.

What medications are safe for Alpha-Gal Syndrome?

Many medications contain hidden mammalian ingredients. Gel capsules and softgels often contain bovine or porcine gelatin. Safe alternatives include tablets, caplets, liquids, and capsules made with vegetable-based HPMC. Always check inactive ingredients for gelatin, magnesium stearate (usually plant-derived in US), lactose, and stearic acid. VectorShield helps patients identify safe medication alternatives.

What are the 4 sensitivity levels of Alpha-Gal Syndrome?

Alpha-Gal sensitivity varies by patient: Level 1 (Mild, ~40%) - react only to mammalian meat; Level 2 (Moderate, ~30%) - also react to gelatin products; Level 3 (Significant, ~20%) - also react to dairy products; Level 4 (Severe, ~10%) - react to trace amounts and cross-contamination, sometimes called 'super reactors'. Sensitivity can change over time, especially with additional tick bites.

Can Alpha-Gal Syndrome be cured?

There is currently no cure for Alpha-Gal Syndrome, but many patients see improvement over time if they avoid additional tick bites. Some patients report tolerance returning after 1-5 years of strict avoidance and no new tick exposures. However, a single new tick bite can restart or worsen the condition. Management focuses on strict avoidance of trigger foods and carrying emergency medication like epinephrine.

CDC sourceContent informed by CDC Alpha-Gal Syndrome resourcesView CDC resources

Learning center

Understanding Alpha-Gal Syndrome.

Trusted, CDC-sourced information for patients, families, and healthcare providers. Pick a path below, or start with the fundamentals.

450K+

Estimated US cases

110K+

Suspected 2010-2022

2-6 hrs

Reaction delay

Expanding

Geographic range

Source: CDC Alpha-Gal Syndrome surveillance data (2023).

Choose your path

Where do you fit in?

Each track is written for a specific reader, so you skip the parts that aren't yours.

Start here

For patients

Newly diagnosed? Learn how to manage AGS day to day, navigate dining, and find safe foods and medications.

Read the guide

For family & caregivers

Supporting someone with AGS? Understand the condition, help with meal planning, and know what to do in an emergency.

Read the guide

CME available

For healthcare providers

Clinical background, testing context, and links to free CDC continuing-education resources.

Read the guide

The fundamentals

Start with the basics.

Four short reads that explain the condition, how reactivity varies, and what's safe to eat.

What is Alpha-Gal?A complete overview: how a tick bite changes the way your body reacts to mammalian meat.Sensitivity levelsFrom avoiding meat only to reacting to traces — understand where you fall and why it matters.Safe & unsafe foodsAlways-safe staples, foods to avoid, and the gray areas that depend on your sensitivity.Research & newsRecent studies, surveillance updates, and what researchers are learning about AGS.

A group sharing a meal together at a table

Alpha-Gal doesn't have to mean eating alone or in fear. Understanding the condition is the first step to eating with confidence again.

Using VectorShield

A walkthrough of the app.

Check whether a medication hides mammalian ingredients, find restaurants with real cooking-fat data, and log meals alongside a community that gets it. The app guide covers every screen, step by step.

Open the app guide

The VectorShield medication safety checker screen

Support

Answers and fixes.

Already using the app? Start with the FAQ, or jump straight to step-by-step fixes for common issues.

Frequently asked questionsWhat the app does, free vs. premium, data privacy, sensitivity levels, and Apple Watch support.TroubleshootingStep-by-step fixes for HealthKit permissions, notifications, Watch sync, meal logging, and subscriptions.

Emergency information

Anaphylaxis is life-threatening. If you or someone near you has difficulty breathing, throat swelling, a rapid heartbeat, or loses consciousness after eating mammalian meat:

Call 911 immediately
Use epinephrine (EpiPen) if prescribed
Lie flat with legs elevated

Put it into practice.

VectorShield turns everything you've learned into a few taps — medication checks, restaurant data, and meal logging in one place.

See how the app helps