GLP-1 Q&A library

Not directly. Hair shedding (telogen effluvium) is reported by some patients ~3 months into rapid weight loss — typical of any rapid-weight-loss state, not unique to GLP-1.

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No hard contraindication, but alcohol tolerance often drops sharply on GLP-1. Many patients also report reduced desire for alcohol — likely a secondary effect of GLP-1 on the brain reward system.

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Tirzepatide (Mounjaro, Zepbound) has documented reduced absorption of oral contraceptives during the first 4 weeks of each dose increase. Use backup contraception for ~4 weeks after starting + after each step-up. Semaglutide has no documented effect.

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No. All FDA-approved GLP-1s carry a pregnancy contraindication. Stop GLP-1 at least 2 months before planned conception due to its long half-life.

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List price runs ~$1,350/mo at retail. NovoCare Pharmacy cash-pay direct from Novo Nordisk is $499/mo for all dose strengths. The Wegovy Savings Offer caps copay at $0-$225/mo for commercially insured patients depending on coverage status (not a flat $225 for everyone).

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Liraglutide has 15+ years of post-marketing data (Victoza approved 2010). Semaglutide has 8+ years (Ozempic approved 2017). No new class-wide safety signals have emerged in extended follow-up. Chronic use is the FDA-approved indication for both T2D and obesity.

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Yes — resistance training specifically. Without it, 25-40% of weight lost on GLP-1 comes from lean muscle. Cardio is a bonus; resistance is the non-negotiable.

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Tirzepatide activates two gut hormones (GIP + GLP-1) that signal fullness to the brain at supra-physiologic levels. It's not willpower; the drug is mimicking your body's satiety signals.

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If within 5 days: take the missed dose as soon as you remember, then resume the regular schedule. More than 5 days late: skip it and inject your next scheduled dose. Never double up.

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Appetite changes in 1-2 weeks. Visible weight loss usually starts in week 4-6. Significant fat loss accelerates in weeks 12-44 as the dose escalates.

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The boxed warning is based on rodent studies showing medullary thyroid carcinoma (MTC) in mice and rats. No human cases have been attributed to GLP-1 use despite 10+ years post-approval surveillance.

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Acute pancreatitis is a rare known risk. Absolute incidence in trials is small (≤0.2% per year) and not significantly higher than placebo in the cardiovascular outcome trials. Personal history of pancreatitis is a relative contraindication.

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Yes. Modern GLP-1 medications are produced via yeast fermentation, not animal sources. The pen device and packaging contain no animal-derived materials in current FDA-approved products.

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Avoid greasy, fried, and ultra-processed foods (worst nausea), high-sugar drinks (rapid reflux), and large portions of red meat or cruciferous vegetables (slow gastric emptying compounds GI side effects). Adequate protein + soluble fiber + hydration are the wins.

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Yes — the combination is FDA-approved and commonly prescribed for type 2 diabetes. There is no metabolic interaction. The two share a GI side-effect profile, so titrate the GLP-1 slowly to minimize compounding nausea.

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Most non-responders fall into 4 buckets: dose hasn't reached maintenance (2.4 mg), titration was interrupted, calorie intake creeps to match satiety, or a hormonal/medical confounder (hypothyroid, PCOS-with-insulin-resistance, sleep apnea). Talk to your prescriber if no measurable loss by week 16 at maintenance dose.

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Mixed evidence. The FDA label has a precaution but no boxed warning. Some patients report improved mood (likely from weight loss + glycemic control); a smaller subset reports increased anxiety or low mood, especially in early weeks. Pre-existing depression history is a flag for closer monitoring.

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Yes. GLP-1 medications combine safely with all major antihypertensive classes (ACE inhibitors, ARBs, beta blockers, diuretics, calcium channel blockers). Weight loss on a GLP-1 often lowers BP, so monitor and reduce antihypertensives as needed to avoid hypotension.

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Refrigerate unopened pens at 36-46°F (2-8°C) until first use. Once started, room temperature ≤86°F (30°C) is fine for up to 28 days. Never freeze; never store in direct sunlight; do not store in checked luggage.

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Most commercial insurance plans cover Zepbound with prior authorization for adults with BMI ≥30 (or ≥27 + a weight-related comorbidity). Medicare Part D excludes anti-obesity drugs by federal law, so Medicare patients pay cash unless they qualify for Lilly Cares.

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Most GI side effects (nausea, constipation, reflux) peak in weeks 1-2 after each dose increase and resolve within 4 weeks. If you stay on a stable dose without further titration, side effects typically fade for ≥80% of patients by week 12.

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Yes — with deliberate resistance training and adequate protein. Without it, 25-40% of weight lost on GLP-1 comes from lean muscle. Lifting 2-3x/week + 1.2-1.6 g/kg ideal-body-weight protein preserves and can grow muscle while losing fat.

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Same active molecule (semaglutide), different FDA indications and maximum doses. Ozempic = type 2 diabetes, max 2 mg/week. Wegovy = chronic weight management, max 2.4 mg/week. Insurance pathways are very different.

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Yes — primarily via weight loss and improved insulin sensitivity. Smaller trials show improved ovulatory cycles and reduced androgen symptoms in women with PCOS. No GLP-1 is FDA-approved for PCOS; use is off-label and weight-driven.

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GLP-1 medications delay gastric emptying as part of their mechanism — that is not stomach paralysis. True gastroparesis after GLP-1 use is rare and the absolute risk in pharmacovigilance data is small. Symptoms (severe nausea, vomiting, abdominal pain past week 8) warrant evaluation.

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Rotate sites between abdomen (≥2 inches from navel), front of thigh, and back of upper arm. Inject at room temperature (cold pens sting). Pinch a fold of skin, insert at 90°, hold 6 seconds after the click, withdraw straight. Dispose in a sharps container.

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Yes — rapid weight loss of any kind increases gallstone risk, and GLP-1 trials show ~1-3% incidence of cholelithiasis vs ~0.5% placebo. The risk is weight-loss mediated, not drug-specific.

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Yes. GLP-1 medications do not interact with levothyroxine or other thyroid hormones. Take levothyroxine on its usual empty-stomach schedule (30-60 min before food); GLP-1 has no effect on its absorption.

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For semaglutide: no — FDA declared the shortage resolved February 21, 2025 and 503A compounding is no longer broadly permitted. For tirzepatide: shortage resolved October 2024 (re-affirmed December 2024), with a wind-down enforcement window that ended in 2025. Some clinics still market "compounded" formulations with added ingredients (B12, glycine) as personalized prescriptions; the legal status is contested.

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No GLP-1 is FDA-approved for type 1 diabetes. Some endocrinologists prescribe semaglutide off-label as an insulin adjunct in T1D with obesity or insulin resistance, but evidence is limited and DKA risk during gastric-emptying changes requires careful monitoring.

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Both are GLP-1 agonists from Novo Nordisk. Wegovy (semaglutide, weekly) produces ~15% mean weight loss; Saxenda (liraglutide, daily) produces ~6-8%. Wegovy is also cheaper per kg-lost, more convenient, and has cardiovascular outcome data (SELECT trial). Saxenda was first approved for adolescents (2020); Wegovy followed in 2022 — both are available for ages 12-17.

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Yes — Wegovy is FDA-approved for ages 12+ with BMI ≥95th percentile for age. Saxenda is approved 12+ with BMI ≥30 kg/m² equivalent. Zepbound is approved 12+ (2024 label update). All require pediatric/adolescent medicine specialist oversight.

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Most people regain about two-thirds of lost weight within 1 year of stopping, based on STEP-1 extension and STEP-4 withdrawal data. Continued lifestyle support reduces the rebound. Most clinicians now treat obesity as a chronic condition requiring ongoing treatment, similar to hypertension.

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Yes. Zepbound (tirzepatide) became the first medication FDA-approved for moderate-to-severe obstructive sleep apnea in adults with obesity (December 2024). SURMOUNT-OSA trial showed 25-30 events/hour AHI reduction with tirzepatide vs placebo.

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Yes, in many cases. Post-bariatric weight regain affects 20-30% of patients within 2-5 years. GLP-1 added to bariatric surgery (sleeve, RYGB) has shown additional weight loss in observational studies and small RCTs. Discuss with your bariatric surgeon.

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Some weight loss happens regardless — appetite is reduced enough that calories drop naturally. But the trial-magnitude weight loss (10-22%) was achieved with structured diet and counseling. Without any nutrition support, expected weight loss is closer to 5-10%.

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Yes for most patients with CKD stages 1-3. Semaglutide has FLOW trial data showing kidney protection. Doses do not require renal adjustment. Severe CKD (eGFR <15) is not a contraindication but warrants nephrology coordination, particularly during early titration when dehydration risk from nausea/vomiting is highest.

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A small observational study (JAMA Ophthalmology 2024) flagged a possible association between semaglutide and NAION (non-arteritic anterior ischemic optic neuropathy) — a rare cause of sudden vision loss. Subsequent analyses have been mixed. Any sudden vision change while on GLP-1 warrants urgent ophthalmology referral.

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Yes, and many patients do — SURMOUNT-5 (NEJM 2025) showed tirzepatide produced 20% mean weight loss vs 14% for semaglutide. Switching is usually done with a 1-week washout, starting Zepbound at 2.5 mg regardless of prior Wegovy dose.

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Yes. Multiple GLP-1 trials show liver-fat reduction and improvement in fibrosis markers. Tirzepatide (SYNERGY-NASH, NEJM 2024) achieved NASH resolution without worsening fibrosis in 44-62% of patients vs 10% placebo across the 5/10/15 mg dose arms. Semaglutide has similar but slightly smaller effect.

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GLP-1 alone has very low hypoglycemia risk — its insulin-secretion mechanism is glucose-dependent. Hypoglycemia risk rises sharply when GLP-1 is combined with insulin or sulfonylureas; those medications usually need dose reduction at GLP-1 start.

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Yes, modestly. GLP-1 medications reduce triglycerides 10-20%, LDL 5-10%, and ApoB ~7%. Most of the effect comes from weight loss, but a small drug-specific effect appears to be present in subgroup analyses.

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Yes. There are no clinically significant interactions between GLP-1 medications and SSRIs, SNRIs, bupropion, or most other antidepressants. Mood-related side effects of GLP-1 (mostly increased fatigue during titration) are unrelated to antidepressant interactions.

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Some lean-mass loss is expected with any weight loss — typically 25-30% of total weight lost comes from lean tissue. With adequate protein (1.2-1.6 g/kg ideal body weight) and resistance training 2-3×/week, the lean-mass fraction can be reduced to 15-20%.

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Yes — about 20-25% of patients experience constipation during titration. Mechanism is delayed GI motility plus reduced food + fluid intake. Most cases resolve with fiber, fluid, and walking; some need short-term osmotic laxatives (polyethylene glycol).

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Yes. ASA 2023 guidance recommends holding daily GLP-1 (liraglutide) for 1 day, weekly GLP-1 (semaglutide, tirzepatide) for 1 week before elective procedures requiring anesthesia. The reason: delayed gastric emptying increases aspiration risk on induction.

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Yes. There is no interaction between caffeine and GLP-1 medications. Some patients find coffee on an empty stomach is harder to tolerate during titration weeks (more nausea); switching to coffee with food, or temporary reduction, usually solves this.

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Indirectly, yes — appetite suppression often reduces total fluid intake, and titration-week nausea/vomiting/diarrhea cause direct fluid losses. Acute kidney injury cases in surveillance data almost all trace back to severe dehydration.

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Promising preliminary evidence. Small RCTs and case series show GLP-1 reduces binge frequency and food-reward cravings in adults with BED. No GLP-1 is FDA-approved for BED yet; lisdexamfetamine (Vyvanse) remains the only approved pharmacotherapy.

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Modestly — semaglutide raises resting heart rate by about 2-4 beats/min on average, tirzepatide ~3-5 beats/min. The increase is not associated with worse cardiovascular outcomes; the SELECT trial showed semaglutide reduces MACE by 20% despite the HR rise.

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In adults with PCOS or obesity-related infertility, GLP-1-mediated weight loss often improves ovulation and fertility. There is anecdotal "Ozempic baby" reports of unplanned pregnancies after years of infertility. GLP-1 is not recommended during pregnancy and should be stopped at least 2 months before conception attempts.

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Yes for semaglutide — SELECT (NEJM 2023) showed a 20% reduction in major adverse cardiovascular events (MACE: heart attack, stroke, CV death) in adults with obesity + established cardiovascular disease, even without diabetes. Tirzepatide data is pending (SURMOUNT-MMO trial reports 2026-2027).

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Approval rates vary by insurer from 30-70%. The highest-yield steps: documented BMI ≥30 (or ≥27 with a comorbidity), at least one documented diet/exercise attempt, baseline labs (A1c, lipids), prescriber notes citing FDA indication, and same-day appeal of denials with the carrier-specific reason. See /insurance-appeal/[carrier]/[drug] for templates.

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Yes, commonly. Patients frequently report aversions to previously-enjoyed foods (especially fried, very rich, or very sweet items), reduced interest in alcohol, and sometimes a metallic or "off" taste. These usually emerge in the first 4-8 weeks and may persist throughout treatment.

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Rybelsus 14 mg daily is roughly equivalent to Ozempic 0.5 mg weekly for A1c reduction. For weight loss, injectable doses (up to 2.4 mg Wegovy) are substantially more effective than the current oral 14 mg max. Higher-dose oral semaglutide (25 mg, 50 mg) is in development.

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List prices ($1,100-$1,350/mo) reflect manufacturer pricing, US-specific lack of price negotiation (until IRA implementation), and high R&D recovery on patent. Cash and PAP programs now bring effective prices to $349-$499/mo (NovoCare Pharmacy, Lilly Direct).

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Promising preliminary signal for both. GLP-1 acts on brain reward circuits that overlap with addiction pathways. Several RCTs in alcohol use disorder (AUD) and opioid use disorder (OUD) are underway. As of 2026, no GLP-1 is FDA-approved for any addiction indication.

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Yes, with monitoring. GLP-1 does not directly interact with warfarin, but rapid weight loss + changing food intake patterns can shift INR. Plan for more frequent INR checks (weekly during titration, then settle to monthly).

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