When Your GLP-1 Isn't Working

Find what's blocking it, then work on that

This is the functional medicine side of weight loss in Barrington, where comprehensive testing is used to identify the metabolic, gut, hormone, and inflammation problems that keep a weight loss medication from doing its job.



If the scale has stopped moving, or never moved much to begin with, that is usually a signal about something underneath rather than a signal about your effort. Dr. Jung works alongside your prescriber to find out what.

Across major semaglutide and tirzepatide studies, roughly 10% to 15% of patients did not lose at least 5% of their starting body weight.

What actually gets in the way of a GLP-1 working

Non-response is rarely about willpower or dosing. These medications work by mimicking the incretin hormones that regulate insulin, slow digestion, and reduce appetite, which means they depend on systems that have to be functioning to respond. When one of those systems is already compromised, the medication is working against a headwind:

• Metabolic roadblocks, where cells cannot produce energy efficiently and the body resists releasing fat regardless of how well appetite is controlled
• Gut imbalance, where a disrupted microbiome produces fewer short-chain fatty acids and weakens the gut-to-brain signaling these medications rely on
• Chronic inflammation, where elevated markers drive leptin and insulin resistance so fullness signals stop registering, often kept running by unresolved low-grade infections or toxin exposure
• Hormone imbalance, where a sluggish thyroid or persistently elevated cortisol lowers metabolic rate and pulls against the medication
• Advanced insulin resistance, where insulin has been elevated long enough that receptor sensitivity has dropped below what a GLP-1 alone can recover
• Nutrient gaps, where low B vitamins, magnesium, or zinc limit the enzyme activity that fat metabolism depends on

More than twenty distinct mechanisms have been documented, and Dr. Jung's forthcoming book, The GLP-1 Resistance Factor, catalogs them in detail. In practice, most patients have two or three running at once, which is why finding them matters more than guessing at them.

The testing that shows which one is yours

You cannot treat a mechanism you haven't identified. The evaluation starts with history and symptoms, then uses testing to confirm what the history suggests. Which panels get ordered depends on your situation rather than a fixed list.

Conventional panels

• Comprehensive metabolic panel, HbA1c, and fasting insulin, to establish how your body is currently handling glucose
• Full thyroid panel including TSH, Free T3, Free T4, and Reverse T3
• Lipid panel, to see how the metabolic picture is affecting cardiovascular risk

Functional panels

• Inflammatory markers including hs-CRP and homocysteine
• Micronutrient testing for the vitamins and minerals fat metabolism depends on
• Comprehensive stool analysis for microbiome balance and digestive function
• Heavy metal or mold toxin panels, when your history points in that direction

What changes once the results come back

Results drive the plan, so no two look identical. What they have in common is that each piece is there for a documented reason:

• Nutrition built around adequate protein and fiber, to preserve lean muscle while weight comes down
• Resistance training paired with lower-intensity zone 2 cardio, to rebuild baseline insulin sensitivity
• Sleep and stress work, since 7 to 9 hours and lower cortisol change how your body handles fuel
• Targeted supplements where testing supports them, which may include berberine for glucose regulation or ashwagandha for cortisol, used under clinical supervision
• Acupuncture, to support autonomic regulation and digestion alongside the rest of the plan

None of this replaces your medication or your prescriber's judgment. The point is to clear what is standing in its way.

The clinical background behind this approach

Real stories from patients like you

What Barrington patients say about their care

How the process works, from questionnaire to re-test

Step 1: The screening questionnaire
Every functional medicine patient starts here. Your answers narrow down which system is most likely driving the plateau, whether that is thyroid, adrenal, hormonal, digestive, or an inflammatory or food-sensitivity pattern, so testing begins with a target rather than a wide net.

Step 2: Testing chosen from what the questionnaire shows
Conventional bloodwork covers the metabolic and thyroid picture. Where the questionnaire points elsewhere, that can include saliva panels, comprehensive stool analysis, or DUTCH hormone testing, which read things standard blood panels are not designed to capture.

Step 3: Weeks 1 and 2, baseline and foundation
Labs are drawn and the fundamentals get set: hydration, protein adequate to protect lean muscle, and consistent sleep to bring nighttime cortisol down.

Step 4: Weeks 3 through 12, layered in sequence
Nutrition and aerobic work come first, then micronutrient support, then any adaptogens or metabolic supplements the labs actually justify, along with acupuncture where it fits. Each layer is added deliberately so it is clear what is working.

Step 5: Re-testing at 12 weeks
Fasting insulin, hs-CRP, and Free T3 get re-run and compared against your baseline. Those results go back to your prescriber, who decides what happens with your medication from there.

Start with the testing, not another restart

If you have already restarted, adjusted, or waited it out without much changing, more of the same is unlikely to produce a different result. Call the Barrington office and we will walk you through what a first evaluation covers and whether this is a reasonable fit for your situation.