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

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Frequently asked questions

Quick answers about what VectorShield does, what is free, where your data lives, and how the app fits your sensitivity level. Something not working? Try the troubleshooting guide.

About the app

What is VectorShield?

What does VectorShield do?

VectorShield (AGS Monitor) is an iPhone and Apple Watch app for people managing Alpha-Gal Syndrome. It helps you log meals and reactions, check medications and products for ingredients commonly associated with alpha-gal, find restaurants with real cooking-fat and accommodation notes, and keep an organized history to share with your healthcare provider.

Who is it for?

Anyone living with or supporting someone with Alpha-Gal Syndrome: newly diagnosed patients figuring out what is safe, long-time patients who want a faster way to check medications and restaurants, and family members or caregivers helping with meal planning.

Does the app diagnose Alpha-Gal Syndrome?

No. VectorShield does not diagnose any condition and does not provide medical advice. It is a tracking and reference tool. Diagnosis requires testing and evaluation by a qualified healthcare provider.

Pricing

What is free and what is paid?

What do I get for free?

The free tier includes 5 medication searches per day, meal logging, health monitoring, the Apple Watch app, and reaction logging. You can use the core of the app every day without paying anything.

What does Premium add?

Premium is $2.99 per month and unlocks unlimited medication and food searches, the ability to save medications for quick re-checking, an offline database, and extended history.

Is anything safety-critical behind the paywall?

No. Emergency medication lookup (such as epinephrine auto-injectors) and the emergency call button are never paywalled. Core safety features and basic reaction logging stay free for everyone, always.

Privacy

Where does my data live?

Is my health data private?

Yes. Your meal, reaction, and health history is stored on your device and in your personal iCloud account. It is not sold, shared, or used for advertising.

What about community features?

Community features (posts, reviews, recipes) are optional and use a separate account. Nothing you log privately is ever posted; only content you explicitly choose to share appears in the community.

Sensitivity levels

How do sensitivity levels work?

What are the four sensitivity levels?

Level 1: avoid mammalian meat only (about 40% of patients). Level 2: also avoid gelatin (about 30%). Level 3: also react to dairy (about 20%). Level 4: react to traces - sometimes called super reactors (about 10%). The app personalizes how foods, medications, and products are rated based on the level you choose.

Can I change my sensitivity level later?

Yes, at any time in Settings. Many people refine their level as they learn more about their own reactions. Talk to your allergist if you are unsure where you fall.

Read the full sensitivity levels guide

Apple Watch

Does it work with my watch?

Does VectorShield support Apple Watch?

Yes. The Watch app lets you log meals by voice and review your recent history from your wrist. It is included in the free tier.

Do I need an Apple Watch specifically?

VectorShield connects through Apple HealthKit, so it works with any wearable that writes its data to HealthKit - not just Apple Watch. The dedicated on-wrist app is Apple Watch only.

Medical disclaimer

Is this medical advice?

Is VectorShield medical advice?

No. VectorShield is for informational and self-tracking purposes only. It does not provide medical advice, diagnosis, or treatment, and it is not a substitute for professional medical care. Always consult your healthcare provider about your condition, and call emergency services if you think you are having a severe reaction.

VectorShield is for informational and self-tracking purposes only. It does not provide medical advice, diagnosis, or treatment, and it is not a substitute for professional medical care. Always consult your healthcare provider about your condition.

Still have a question?

Check the troubleshooting guide for fixes to common issues, or get in touch and a real person will answer.

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