Expert Q&A

Being underweight, panic and anxiety. Recently got thyroid lab tested if you're on a GLP-1 like semaglutide or tirzepatide

Understanding Being Underweight on GLP-1 Medications

I see many adults in their late 40s and early 50s facing unexpected weight drops while using GLP-1 agonists like semaglutide or tirzepatide. These powerful medications slow gastric emptying and reduce appetite, which works wonders for those with obesity, diabetes, or high blood pressure. However, if you start at a lower BMI or experience rapid loss exceeding 2 pounds per week, you can slip into being underweight. This triggers real physical stress that often amplifies panic and anxiety symptoms.

My book, The Metabolic Reset Protocol, explains how GLP-1s interact with your body's natural hunger signals. For middle-income beginners overwhelmed by conflicting advice, the key is personalized titration. Never exceed 2.4 mg weekly for semaglutide or 15 mg for tirzepatide without close monitoring. Joint pain and hormonal changes around menopause make exercise feel impossible, so we focus on gentle strength training twice weekly using bodyweight moves that protect your knees and back.

Interpreting Your Recent Thyroid Lab Results

Thyroid function must be checked before and during GLP-1 therapy because these drugs can subtly alter TSH, free T4, and T3 levels. If your labs show elevated TSH above 4.0 mIU/L while on semaglutide, it may signal compensatory changes rather than true hypothyroidism. In my practice, I recommend retesting every 8-12 weeks. Being underweight can suppress T3 conversion, worsening fatigue and anxiety. Always share your full panel—including antibodies if you have autoimmune concerns—with your provider. Insurance often covers these tests when coded for metabolic syndrome management.

Strategies to Ease Panic and Anxiety

Panic attacks and racing thoughts are common when weight falls too low because your brain senses starvation and floods cortisol. From The Metabolic Reset Protocol, I teach the 4-7-8 breathing technique: inhale for 4 seconds, hold 7, exhale 8. Practice three times daily. Pair this with 20 grams of protein at every meal to stabilize blood sugar—critical when managing diabetes alongside weight changes. If anxiety persists, low-dose magnesium glycinate at 200 mg nightly often helps without adding calories. Avoid complex meal plans; instead, use my simple plate method: half non-starchy vegetables, quarter lean protein, quarter complex carbs like quinoa.

Practical Next Steps for Safe Progress

Track your weight weekly, not daily, aiming to stabilize between 18.5-24.9 BMI. If underweight, reduce your GLP-1 dose by 25% for two weeks and add 300 calories of nutrient-dense foods like avocado or nuts. Schedule a follow-up thyroid panel in 30 days. For those embarrassed to ask for help with obesity-related issues, remember that joint pain improves dramatically once inflammation drops. Start with 10-minute daily walks and build from there. This approach fits busy schedules without gym memberships insurance won't cover. Consistent application of these principles from The Metabolic Reset Protocol helps reverse the cycle of failed diets and hormonal frustration.

💬 What the Community Says

Users in midlife forums report mixed experiences with being underweight on semaglutide and tirzepatide. Many in their 40s-50s describe sudden anxiety spikes and panic attacks once BMI dips below 19, often linking it to low blood sugar or thyroid fluctuations. A common theme is frustration with insurance not covering nutritional counseling, pushing people toward self-experimentation with dose adjustments. Most practitioners find that lowering the weekly dose and adding protein snacks helps stabilize mood within two weeks, though a vocal minority warns against abrupt stops due to rebound weight gain. Beginners frequently share embarrassment about rapid loss looking "unhealthy" to family, while others celebrate improved joint pain and blood pressure numbers. Debates continue on optimal thyroid monitoring frequency, with lived experiences highlighting the need for more accessible beginner-friendly protocols that don't require complex tracking.
Cite this answer
Clark, R. (2026). Being underweight, panic and anxiety. Recently got thyroid lab tested if you're . *CFP Weight Loss*. https://ask.cfpweightloss.com/ask/being-underweight-panic-and-anxiety-recently-got-thyroid-lab-tested-if-you-re-on-a-glp-1-like-semaglutide-or-tirzepatide
Russell Clark, FNP-C, APRN, FNP-C, APRN
About the Author

Russell Clark, FNP-C, APRN, is the founder of CFP Weight Loss in Nashville and CFP Fit Now telehealth. Over 35 years in healthcare — Army Nurse Reserves, Level 1 trauma ER, hospitalist — he developed a 30-week protocol integrating real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 30–90 pounds. He and his wife Anne-Marie lost a combined 275 pounds using the same protocol.

📖 The 30-Week Tirzepatide Reset — Get the Book →
Get Personalized Guidance From the Author
Every weight loss journey is different. Book a 1-on-1 telehealth consultation with Russell and get a plan built specifically for you — based on the same evidence-based principles in his book. Available to patients in all 50 states.
Book Your Consultation →
Have a follow-up question?
More Questions 200 answered
▸ Omnipod. Starting an insulin pump help while doing intermittent fasting for long-term maintenance (not just short-term)? ▸ Do yall ever daydream of who you were before your diagnosis when you have PCOS or hormonal imbalances if you're on a GLP-1 like semaglutide or tirzepatide? ▸ What actually helps with the dryness when you have PCOS or hormonal imbalances while doing intermittent fasting? 📖 Autophagy — The body's natural 'housecleaning' process that occurs during fasting or low-insulin states, promoted during our mainten… ▸ Anyone remember the metal lid you had to use a butter knife to pop off: what to track and how to measure progress while doing intermittent fasting? ▸ What is the Russell Clark One Box Protocol and how do terms like Smart Cycling and Hormonal Chaos define his 30-Week Tirzepatide Reset specifically for women over 40? ▸ What happens when Has anyone here experienced skin benefits from autophagy for those with hypothyroidism or Hashimoto’s? ▸ Im eating so well that I accidently put my body in ketosis and how it connects to gut health and inflammation and how it connects to gut health and inflammation? ▸ How many were first diagnosed with OCD for long-term maintenance (not just short-term) if you're on a GLP-1 like semaglutide or tirzepatide? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ What foods to stock for overnight guest — evidence-based answer for CFP patients: what to track and how to measure progress? 📖 Strategic Fat Loading — A critical 48-hour phase at the start of the reset where we prime the body with healthy fats to trigger the transition f… ▸ Testosterone how long does it take to work while doing intermittent fasting if you're on a GLP-1 like semaglutide or tirzepatide? ▸ Compression socks. Worth it? Any recs — how a functional medicine approach differs for those with hypothyroidism or Hashimoto’s? ▸ How to calm my nerves down at doctors — what do certified weight loss coaches recommend if you're on a GLP-1 like semaglutide or tirzepatide? ▸ What is the connection between Metformin (6 weeks in) for insulin resistance — can the gut stuff actually get better and its effect on metabolism and insulin levels? ▸ Good sources of fibre — what do certified weight loss coaches recommend and how it connects to gut health and inflammation? ▸ What is a super quick "Mix some of this in" to make coconut oil (purely in liquid form) taste ok to make it easy to consume: how to talk to your doctor about this during the weight loss plateau phase? 📖 Caloric Deficit Myth — The false belief that weight loss is purely 'math'; we focus on hormonal signaling rather than just counting calories to… ▸ Is anyone else worried about judgment from others for those with hypothyroidism or Hashimoto's during the weight loss plateau phase? ▸ Is it okay for teenagers to do longterm lowcarb/keto — evidence-based answer for CFP patients for those with hypothyroidism or Hashimoto’s? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ I sometimes feel like people only talk about the obvious symptoms like irregular periods or weight gain, but the fatigue can be just as overwhelming. Has anyone else felt completely drained even: how to talk to your doctor about this: best practices and common mistakes to avoid? ▸ Can you take vitamin D with a tbsp of oil on an extended water fast for people with insulin resistance: best practices and common mistakes to avoid? ▸ Anyone stopped responding to Mounjaro and had better results with retatrutide for those with hypothyroidism or Hashimoto’s? 📖 Metabolic Efficiency — The state where your body processes fuel cleanly and maintains high energy levels without the need for constant snacking… ▸ Sugar free pudding with greek yogurt — evidence-based answer for CFP patients for long-term maintenance (not just short-term)? ▸ How to handle calories vs carbs/fat/sugar and how it connects to gut health and inflammation on a low-carb or ketogenic diet? ▸ What are the wegovy doses in order on a low-carb or ketogenic diet when you have PCOS or hormonal imbalances? ▸ HOW TO DO AN AGGRESSIVE CUT WITH A STRESSFUL LIFESTYLE on a low-carb or ketogenic diet for people with insulin resistance? 📖 Refined Carbohydrates — Processed sugars and flours that strip the body of nutrients while driving the hormonal chaos responsible for the modern… ▸ Is the idea of the kitchen timer to eventually get to the point where someone has an orgasm just from hearing the ding? Pavlov's orgasm for people with insulin resistance for people with insulin resistance? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Why cant i lose weight and am gaining weight when you have PCOS or hormonal imbalances for those with hypothyroidism or Hashimoto’s? ▸ What to do if you have to eat late dinners?? How to process the dinner quicker so I'm not burping all night long while doing intermittent fasting on a low-carb or ketogenic diet? ▸ How much keto-ade should I safely drink: best practices and common mistakes to avoid and how it connects to gut health and inflammation? ▸ When you want something sweet but still try to keep things somewhat low-carb and how it connects to gut health and inflammation on a low-carb or ketogenic diet? 📖 High-Dose Dependency — The pharmaceutical trap of staying on maximum medication doses indefinitely, which we avoid through our smart cycling me… ▸ How does a 16 hour daily fast induce autophagy for men for long-term maintenance (not just short-term)? ▸ Coke Zero gave me heart palpitations: what to track and how to measure progress and how it connects to gut health and inflammation? ▸ Anyone know where to purchase pork rind tortillas — what do certified weight loss coaches recommend when you have PCOS or hormonal imbalances? ▸ How much protein should I eat if I weigh 280 pounds and want to cut a 100 pounds of fat off of my body? ▸ Got diagnosed today, where do i go from here — what do certified weight loss coaches recommend — what certified coaches recommend? 📖 Adipose Tissue Signaling — The way fat cells communicate with the brain; our goal is to fix these signals so the body stops defending an unnaturall… ▸ What are some things you loved from your childhood that you (virtually) never see/experience anymore during the weight loss plateau phase on a low-carb or ketogenic diet? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Thyroid tests all in range— but high calcium — how a functional medicine approach differs on a low-carb or ketogenic diet? ▸ What to do if you have to eat late dinners?? How to process the dinner quicker so I'm not burping all night long while doing intermittent fasting: what to track and how to measure progress? ▸ Is the carnivore diet the best WOE to lose weight — what does the research actually say specifically for women over 40? ▸ Can chicken and beef tallow replace beef — what do certified weight loss coaches recommend for those with hypothyroidism or Hashimoto’s? 📖 Tirzepatide — A dual-acting medication targeting both GLP-1 and GIP receptors, providing a more comprehensive metabolic signal than si… ▸ To what extent do Mendelian Randomization Studies provide causal evidence for a particular claim — what does the research actually say for those with hypothyroidism or Hashimoto’s? ▸ Tips for maintenance: what’s yours for long-term maintenance (not just short-term): best practices and common mistakes to avoid? ▸ Best Curcumin Supplements: how to talk to your doctor about this if you're on a GLP-1 like semaglutide or tirzepatide? ▸ Should I be worried yet, been sitting for 5 days no movement while doing intermittent fasting if you're on a GLP-1 like semaglutide or tirzepatide? ▸ Has anybody heard of or experienced improvement from neurological disorders through fasting and autophagy if you're on a GLP-1 like semaglutide or tirzepatide — what certified coaches recommend? 📗 The 30-Week Tirzepatide Reset — by Russell Clark, FNP-C, APRN · The complete clinical protocol — 30 weeks of real foods, detox, and low-dose tirzepatide cycling that has helped hundreds of patients lose 3 ▸ Low TSH, Low T4, and Low T3 simultaneously on Levothyroxine — anyone experienced this and the role of cortisol and stress hormones on a low-carb or ketogenic diet? 📖 Nutrient Density — Prioritizing foods that provide maximum vitamins and minerals per calorie to satisfy the brain and end the cycle of hidd… ▸ Difference between a 3 day and 5 day water fast for autophagy and the role of cortisol and stress hormones on a low-carb or ketogenic diet? ▸ Is it normal to lose 6 kg in one week during the weight loss plateau phase for long-term maintenance (not just short-term)? ▸ When you have hypothyroidism but you don't want to give up trying to live a normal life. 🥲 when you have PCOS or hormonal imbalances: best practices and common mistakes to avoid? ▸ How I Lost 22lbs in 3 Months (155→133lbs at 5'8") after not being able to lose weight for a long time if you're on a GLP-1 like semaglutide or tirzepatide during the weight loss plateau phase? ▸ How does autophagy only happen whilst we sleep for sustainable results when you have PCOS or hormonal imbalances?