Lisle, IL

Diagnostic Testing

Comprehensive food sensitivity panels, allergy testing, and combo panels to inform your nutrition and protocol decisions. Serving Lisle, Naperville & Chicago’s western suburbs.

Book a Session

What Is Diagnostic Testing

Data before decisions.

Defiant offers a focused set of diagnostic panels designed to inform nutrition and protocol decisions: IgG-based food sensitivity testing, IgE-based allergy testing, and a combination panel that covers both. Each is a blood-based test drawn in-clinic with results returned in 1 to 2 weeks.

We’re going to be straight about something: IgG food sensitivity testing is debated in the medical literature. We use it as a starting point for elimination work, not as a diagnosis. IgE allergy testing is well established. We’ll match the right panel to your actual symptoms.

Why Clients Test

+ Inform weight loss and peptide protocols
+ Starting point for elimination diets
+ Identify classic environmental allergens
+ Comprehensive results in 1 to 2 weeks
+ Provider walkthrough of results included

Three Panels Available

Pick the panel that fits your symptoms.

Food Sensitivity Panel

An IgG-based panel covering a broad list of common foods. Used as a starting point for elimination-and-reintroduction work when you suspect specific foods are driving low-grade symptoms like bloat, fatigue, skin issues, or brain fog. Honest framing: IgG testing is debated, so we use it as input, not as a diagnosis.

IgG-based, broad food coverage
Informs elimination work
Best for low-grade chronic symptoms

Allergy Test

An IgE-based panel covering common environmental and food allergens. This is the classic allergy test: it measures the immune pathway behind hives, swelling, hay fever, and acute allergic reactions. Well-established methodology with clear clinical use.

IgE-based classic allergy testing
Environmental + food allergens
Strong clinical track record

Combo Panel

Both IgG and IgE in a single draw. Useful when you suspect a mix of classic allergies and lower-grade food triggers, or when you want the broadest snapshot before designing a nutrition plan around a weight loss or peptide protocol.

IgG + IgE in one draw
Most comprehensive snapshot
Common starting point for protocols

How Testing Informs Protocols

Testing fits inside your protocol, not next to it.

These panels matter most when they change a decision. Done in isolation, a panel is just a list of foods. Done in the context of a weight loss, peptide, or recovery protocol, the same panel can shape your nutrition plan, your supplement choices, and the cadence of follow-up.

Nutrition Foundation

Weight Loss Protocols

Persistent low-grade inflammation can blunt energy, complicate appetite signals, and slow progress. For clients on or considering a weight loss protocol, testing can identify foods worth eliminating early so the rest of the plan works better.

· Identify trigger foods early
· Inform nutrition guidance
· Pair with GLP-1 protocols
· Supports better protocol response

Inflammation Inputs

Peptide & Recovery Protocols

Many peptide protocols aim at recovery, gut health, or inflammation. Testing can flag inputs that are working against you, so the peptide is doing useful work rather than fighting an avoidable source of inflammation.

· Identify chronic-load inputs
· Inform peptide stack design
· Pair with BPC-157 protocols
· Better recovery feedback

Considering testing? Bring your symptom list and goals to your appointment. We’ll recommend the panel that fits, and skip the ones that don’t.

What To Expect

How testing works at Defiant.

Symptom Review

Quick intake on your symptoms, history, and goals. We’ll recommend a panel only if it’s likely to change a decision you’re making.

In-Clinic Blood Draw

A standard blood draw at the clinic. Quick visit, no fasting required for most panels.

Results In 1 to 2 Weeks

Lab returns a detailed report. We review the report so you understand what each finding does and doesn’t mean.

Plan Next Steps

Based on your results, we map out elimination, reintroduction, or referral steps. Testing is the starting point, not the end of the conversation.

Diagnostic Testing Pricing

Food Sensitivity Panel (IgG)Pricing discussed at appointment

Allergy Test (IgE)Pricing discussed at appointment

Combo Panel (IgG + IgE)Pricing discussed at appointment

We discuss pricing at your appointment so we can match the panel to your symptoms and goals before quoting.

FAQ

Common Questions

Everything you need to know about food sensitivity, allergy, and combo diagnostic panels at Defiant in Lisle, IL, serving Naperville and Chicago’s western suburbs.

An allergy test measures IgE antibodies, which are the immune response behind classic allergic reactions like hives, swelling, or anaphylaxis. A food sensitivity test measures IgG antibodies, which reflect exposure and immune reactivity but don’t cause the same acute response. IgE testing is well established. IgG testing is debated in the medical literature: we present it as informational input, not a diagnostic.

Honest answer: IgG-based food sensitivity testing is debated. Many mainstream allergy bodies note that IgG antibodies often reflect normal exposure to foods rather than a true sensitivity. We use it as a starting point for elimination-and-reintroduction work, not as a diagnosis. If you want a more conservative approach, an elimination diet without testing is a valid option.

If you suspect classic allergies (hay fever, environmental triggers, food-allergic reactions), the IgE Allergy Test is the right starting point. If you suspect that specific foods are driving low-grade symptoms (bloat, fatigue, skin issues, brain fog), the IgG Food Sensitivity Panel can inform elimination work. The Combo Panel covers both.

Both are blood-based panels. The draw is done in-clinic. Results typically come back in 1 to 2 weeks, and we walk through them with you to plan next steps, including elimination, reintroduction, or referral if needed.

Persistent inflammation from undetected food triggers can make weight loss harder, blunt energy, and complicate peptide protocols. Identifying and addressing triggers often makes the rest of a weight loss protocol work better. We pair testing with protocol decisions, not as a standalone.

Most clients pay out of pocket. Some panels may be reimbursable through HSA or FSA. We don’t bill insurance directly for these panels, ask us for the receipt format if you plan to submit for reimbursement.

Pricing is discussed at your appointment so we can recommend the panel that fits your actual symptoms and goals rather than upselling the most comprehensive option by default.

Defiant is located at 5100 Lincoln Ave, Lisle, IL 60532, serving Naperville, Downers Grove, Wheaton, Bolingbrook, Lombard, and the western Chicago suburbs.

Get Started

Test what’s actually driving symptoms.

Bring your symptom list, your goals, and your questions. We’ll recommend the panel that’s likely to change a decision and skip the one that isn’t. Data before decisions, then a plan you can actually follow.