GLP-1 Glossary

Once-weekly injectable semaglutide approved by the FDA in 2021 for chronic weight management. Same active ingredient as Ozempic but at higher doses (0.25 to 2.4 mg weekly).

View term page →Wegovy in our brand-comparison piece →

Once-weekly injectable semaglutide FDA-approved for type 2 diabetes (0.5, 1, 2 mg). Same molecule as Wegovy but lower target doses; commonly prescribed off-label for weight loss.

View term page →Ozempic drug page →

Oral semaglutide tablets (3, 7, 14 mg daily) FDA-approved for type 2 diabetes. The pivotal pharmacokinetic source for the 33% levothyroxine AUC interaction warning.

View term page →GLP-1 + levothyroxine deep dive →

Once-daily injectable liraglutide 3.0 mg, FDA-approved 2014 for chronic weight management. Shorter half-life (~13 hours) than the once-weekly GLP-1s requires daily dosing.

View term page →GLP-1 side effects investigation →

Once-weekly injectable tirzepatide FDA-approved 2023 for chronic weight management. Dual GLP-1/GIP receptor agonist; produced ~21% body weight reduction at 15 mg in SURMOUNT-1.

View term page →Tirzepatide vs semaglutide head-to-head →

Once-weekly injectable tirzepatide FDA-approved 2022 for type 2 diabetes. Same molecule as Zepbound. Carries the same 4-week backup-contraception warning on oral hormonal contraceptives.

View term page →Mounjaro/Zepbound + birth control →

Orforglipron tablets, the first oral non-peptide GLP-1 receptor agonist, FDA-approved April 2026 by Eli Lilly. Daily oral dosing on empty stomach with a 30-minute fast window.

View term page →How to take Foundayo (orforglipron) →

Generic name for the active ingredient in Wegovy, Ozempic, and Rybelsus. GLP-1 receptor agonist with ~7-day half-life enabling once-weekly subcutaneous dosing.

View term page →Semaglutide drug page →

Generic name for the active ingredient in Mounjaro and Zepbound. Dual GLP-1 and GIP receptor agonist with ~5-day half-life. The only injectable GLP-1 with an FDA-mandated oral contraceptive interaction warning.

View term page →Tirzepatide drug page →

Generic name for Foundayo. The first oral non-peptide GLP-1 receptor agonist. Different mechanism for the oral-contraceptive warning (co-localization in the GI tract) vs tirzepatide's gastric-emptying delay.

View term page →What is orforglipron / Foundayo →

Eli Lilly's investigational triple agonist (LY3437943) targeting GLP-1, GIP, and glucagon receptors. Phase 2 (NEJM 2023, Jastreboff et al.) showed up to 24.2% body weight reduction at 48 weeks at the highest dose. The first phase 3 readout, TRIUMPH-4 (Dec 2025), reported 28.7% mean weight loss in adults with obesity and knee osteoarthritis. Not yet FDA-approved.

View term page →Retatrutide: Lilly's triple agonist evidence →

Novo Nordisk's investigational fixed-dose combination of cagrilintide (long-acting amylin analog) plus semaglutide (GLP-1 agonist). REDEFINE 1 reported 20.4% mean weight loss at 68 weeks (22.7% adherent estimand) versus 14.9% with semaglutide alone. Novo has filed an NDA. The result missed Novo's 25% guidance benchmark but still beat semaglutide monotherapy.

View term page →CagriSema REDEFINE trial results →

Novo Nordisk's long-acting amylin analog. Studied alone (11.5% weight loss at 68 weeks in REDEFINE 1) and as the amylin component of CagriSema combined with semaglutide. Distinct mechanism from GLP-1 agonists — works on amylin receptors that signal satiety via the brainstem.

View term page →CagriSema REDEFINE trial results →

Boehringer Ingelheim and Zealand Pharma's investigational dual agonist of GLP-1 and glucagon receptors. Phase 2 reported up to 19% weight loss at 46 weeks. The phase 3 SYNCHRONIZE program is enrolled; not yet FDA-approved.

View term page →GLP-1 pipeline: survodutide, MariTide, ecnoglutide →

Amgen's investigational once-monthly conjugate combining a GLP-1 receptor agonist with a GIP receptor antagonist. Phase 2 (NEJM 2025) reported 16-20% weight loss. The mechanism is unique: opposite GIP direction versus tirzepatide (which is a GIP agonist). Not yet FDA-approved.

View term page →GLP-1 pipeline: survodutide, MariTide, ecnoglutide →

Sciwind Biosciences' biased GLP-1 receptor agonist (licensed to Pfizer for China). Phase 3 SLIMMER trial reported positive results in Lancet Diabetes Endocrinology 2025. Approved by China's NMPA. Not FDA-approved and not in active US development.

View term page →GLP-1 pipeline: survodutide, MariTide, ecnoglutide →

G-protein coupled receptor that responds to glucagon-like peptide-1. Activation by GLP-1 medications suppresses appetite, slows gastric emptying, and improves glucose-dependent insulin secretion.

View term page →How long does GLP-1 take to work →

Glucose-dependent insulinotropic polypeptide receptor. Tirzepatide is a dual agonist of both GLP-1 and GIP receptors, which is the proposed basis for its larger gastric-emptying delay than the semaglutides.

View term page →Tirzepatide vs semaglutide head-to-head →

A medication that activates two receptors at once. Tirzepatide is the GLP-1/GIP dual agonist currently on the market; CagriSema (cagrilintide + semaglutide) and survodutide (GLP-1/glucagon) are in late-stage trials.

View term page →GLP-1 pipeline: survodutide, maridebart, ecnoglutide →

The rate at which food and oral medications leave the stomach. GLP-1 medications slow gastric emptying — the same mechanism that produces appetite suppression also drives the oral-contraceptive and levothyroxine drug interactions.

View term page →GLP-1 nausea management guide →

Patient term for persistent intrusive thoughts about food and eating. Most patients on GLP-1s report food noise reducing within the first 4-8 weeks. Not a formal medical term but widely reported in cohort studies.

View term page →GLP-1 side-effect questions answered →

A peptide that activates three different metabolic receptors simultaneously — typically GIP, GLP-1, and glucagon. Retatrutide is the first triple agonist in clinical development for weight loss. The glucagon component is hypothesized to add an energy-expenditure effect on top of GLP-1 and GIP appetite suppression.

View term page →Retatrutide: triple-agonist evidence →

A pancreatic hormone co-secreted with insulin that signals satiety via brainstem receptors. Long-acting amylin analogs (cagrilintide) are being studied alone and combined with GLP-1 drugs (CagriSema) to amplify weight loss beyond what GLP-1 monotherapy achieves. Distinct receptor pathway from GLP-1.

View term page →CagriSema REDEFINE trial results →

Diminishing weight-loss response with continued GLP-1 exposure at a stable dose — a form of pharmacological tolerance. Documented in rodent models and clinically suspected in the ~20% of long-term users who plateau before reaching their goal weight despite continued dosing. Postulated mechanism: GLP-1 receptor downregulation or β-arrestin-mediated desensitization. Microdosing protocols and drug holidays have been proposed to mitigate it, but no randomized data exist.

View term page →Top semaglutide trial reading list →

A small organic molecule that activates the GLP-1 receptor without being built from a peptide chain. Survives stomach acid and digestive enzymes intact, eliminating the food-restriction requirement that hampers oral peptide drugs like Rybelsus. Foundayo (orforglipron) is the first FDA-approved non-peptide GLP-1 agonist (April 2026), opening a class of oral pills that may replace injections for patients with moderate weight-loss needs.

View term page →Foundayo drug overview →

A blood test reflecting average blood glucose over the prior 8-12 weeks, measured as the percentage of red-blood-cell hemoglobin glycated by glucose. Used as the primary endpoint in T2D trials. Diagnostic threshold: ≥6.5% = diabetes; 5.7-6.4% = prediabetes; <5.7% = normal. GLP-1 receptor agonists typically reduce A1C by 1.0-2.0 percentage points at maximum dose — clinically meaningful, because each 1-point drop reduces microvascular complication risk roughly 25-35%.

View term page →GLP-1 trial reading list →

Metabolic Dysfunction-Associated Steatohepatitis (MASH) and Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) — the 2023 consensus renamings of NASH and NAFLD. Characterized by hepatic fat accumulation plus inflammation (MASH) or without (MASLD), driven by insulin resistance + obesity. SYNERGY-NASH (Loomba 2024 NEJM, tirzepatide) and ESSENCE (semaglutide phase 3) showed substantial fibrosis improvement, positioning GLP-1s as the first systemic therapies for MASH outside the FXR agonist resmetirom.

View term page →Tirzepatide trial reading list (incl. SYNERGY-NASH) →

The percentage of total body weight lost from baseline, reported as the primary endpoint in modern obesity trials. STEP-1 reported −14.9% TBWL on semaglutide 2.4 mg at 68 weeks; SURMOUNT-1 reported −20.9% TBWL on tirzepatide 15 mg at 72 weeks. TBWL is preferred over absolute kg change because it adjusts for starting body weight — a 15% loss in someone starting at 100 kg (15 kg) and 200 kg (30 kg) is clinically equivalent in metabolic terms.

View term page →STEP-1 trial deep-dive →

A protein fragment released by the pancreas in 1:1 ratio with endogenous insulin. Used clinically to distinguish patients still producing insulin (type 2 diabetes, prediabetes) from those who are not (type 1 diabetes, end-stage type 2). GLP-1 agonists work by augmenting endogenous insulin secretion — patients with very low C-peptide (<0.6 ng/mL) typically respond poorly, which is one reason GLP-1s are FDA-labeled for type 2 (not type 1) diabetes.

View term page →STEP-1 metabolic endpoints →

A blood-based estimate of kidney filtration capacity, expressed in mL/min/1.73m². Normal is ≥90; <60 sustained 3+ months defines chronic kidney disease (CKD). Stage 4 CKD is eGFR 15-29; stage 5 (kidney failure) is <15. The FLOW trial showed semaglutide reduced major kidney-disease events 24% in T2D patients with CKD (Perkovic 2024, PMID 38785209), driving the 2025 FDA label expansion for Ozempic to include kidney-disease progression prevention.

View term page →Top GLP-1 kidney studies →

Fat stored deep inside the abdomen, surrounding organs like the liver, pancreas, and intestines — distinct from subcutaneous fat (under the skin). VAT is more metabolically active and more strongly linked to cardiometabolic disease than subcutaneous fat. GLP-1 receptor agonists preferentially reduce VAT relative to subcutaneous fat in DEXA substudies of STEP-1 and SURMOUNT-1, which helps explain why weight loss on these drugs reverses cardiometabolic risk faster than calorie restriction alone.

View term page →SURMOUNT-1 body-composition endpoints →

The number of apneas (breathing pauses ≥10 seconds) plus hypopneas (breathing reductions with oxygen desaturation) per hour of sleep, measured during polysomnography. Diagnostic thresholds: AHI 5-14 = mild OSA, 15-29 = moderate, ≥30 = severe. SURMOUNT-OSA used AHI reduction as its primary endpoint; tirzepatide 15 mg cut AHI by ~25 events/hour vs placebo.

View term page →SURMOUNT-OSA trial deep-dive →

Sodium N-(8-[2-hydroxybenzoyl] amino) caprylate — the absorption enhancer co-formulated with oral semaglutide (Rybelsus). SNAC transiently increases gastric pH and disrupts the cell membrane just enough to let semaglutide cross into the bloodstream — without SNAC, oral semaglutide bioavailability would be effectively zero. The reason Rybelsus requires a strict 30-minute fast before and after dosing: food disrupts SNAC-semaglutide complex formation. Foundayo (orforglipron) is a non-peptide molecule and doesn't need SNAC, eliminating the food restriction.

View term page →Oral GLP-1 Q&A hub →

Pivotal Phase 3 trial of semaglutide 2.4 mg weekly vs placebo in 1,961 adults with overweight/obesity (Wilding et al, NEJM 2021, PMID 33567185). Mean weight loss 14.9% at 68 weeks.

View term page →STEP-1 side-effect data investigation →

Pivotal Phase 3 trial of tirzepatide 5/10/15 mg weekly vs placebo in 2,539 adults with overweight/obesity (Jastreboff et al, NEJM 2022, PMID 35658024). Mean weight loss 20.9% at 15 mg over 72 weeks.

View term page →Tirzepatide vs semaglutide head-to-head →

Cardiovascular outcomes trial of semaglutide 2.4 mg in 17,604 non-diabetic adults with overweight/obesity and established CV disease (Lincoff et al, NEJM 2023). Major adverse cardiovascular events reduced 20% (HR 0.80, 95% CI 0.72-0.90).

View term page →SELECT trial cardiovascular benefits →

Trial of semaglutide 1 mg weekly in chronic kidney disease + type 2 diabetes (NEJM 2024). Composite kidney outcome (eGFR decline, kidney failure, renal/CV death) reduced 24%, HR 0.76.

View term page →FLOW trial: semaglutide in kidney disease →

Trial of tirzepatide 10/15 mg weekly in obstructive sleep apnea + obesity. Apnea-hypopnea index improved approximately 50% in the tirzepatide arm vs placebo.

View term page →SURMOUNT-OSA trial deep dive →

Trial of semaglutide 2.4 mg in adolescents 12-17 with obesity (Weghuber et al, NEJM 2022). Mean weight reduction 16.7% vs 0.6% placebo. Pediatric trials do not measure facial appearance as an outcome.

View term page →STEP-TEENS adolescent semaglutide →

A composite endpoint used in cardiovascular outcomes trials, typically defined as cardiovascular death + nonfatal myocardial infarction + nonfatal stroke. GLP-1 cardiovascular trials report MACE as the primary endpoint: SELECT (semaglutide in obesity) showed 20% relative risk reduction, SUSTAIN-6 (semaglutide T2D) 26%, LEADER (liraglutide) 13%. Effect size correlates roughly with weight loss but extends beyond what weight reduction alone explains.

View term page →Top GLP-1 cardiovascular studies →

A validated patient-reported outcome measure for heart failure symptoms and physical limitations. Scored 0-100, higher is better. A 5-point improvement is considered clinically meaningful. STEP-HFpEF reported a 7.8-point KCCQ-CSS improvement on semaglutide vs 2.6 on placebo — the primary endpoint that drove the 2024 EMA / FDA filings for semaglutide in HFpEF + obesity.

View term page →Top GLP-1 cardiovascular studies →

Phase 3 randomized trial of orforglipron (Foundayo) for chronic weight management in adults with obesity without diabetes. 72 weeks, N=3,127, conducted across 10 countries (NCT05869903). Primary outcome: −12.4% body weight on 17.2 mg orforglipron vs −0.9% placebo (efficacy estimand); −11.1% vs −2.1% (treatment-regimen estimand). Drove the April 2026 FDA approval of Foundayo — the first FDA-approved oral non-peptide GLP-1 receptor agonist for weight management.

View term page →Foundayo drug overview →

The Impact of Weight on Quality of Life-Lite Clinical Trials version — a 20-item patient-reported outcome questionnaire validated for use in obesity drug trials. Scored 0-100, higher is better; physical-function and psychosocial subdomains are reported separately. Clinically meaningful improvement threshold is ~14.6 points. STEP-1 and SURMOUNT-1 both reported large IWQOL-Lite-CT gains, used by FDA in evaluating quality-of-life claims for Wegovy and Zepbound labeling.

View term page →STEP-1 quality-of-life endpoint →

Semaglutide withdrawal trial that established GLP-1 obesity therapy as chronic — not finite — treatment. After all 803 participants reached the 2.4 mg dose in a 20-week run-in, they were randomized 2:1 to continue semaglutide or switch to placebo for 48 more weeks. Continuers lost another 7.9% body weight; switchers regained 6.9%. Rubino 2021 JAMA, PMID 33755728. Effectively retired the idea of finishing a GLP-1 course.

View term page →STEP-4 trial deep-dive →

Phase 2 randomized trial of tirzepatide in adults with biopsy-confirmed MASH (formerly NASH) + significant fibrosis. Loomba 2024 NEJM (PMID 38856224). Primary endpoint: MASH resolution without worsening fibrosis at week 52 — a histologic endpoint requiring liver biopsy. 62% of patients on 15 mg achieved resolution vs 10% placebo. Positions GLP-1s as first-in-class systemic therapy for MASH outside FXR agonists.

View term page →SYNERGY-NASH trial deep-dive →

First GLP-1 cardiovascular outcomes trial to show MACE reduction. N=9,340 adults with type 2 diabetes + established CVD or high CV risk, randomized to liraglutide vs placebo for median 3.8 years (Marso 2016 NEJM, PMID 27295427). Primary endpoint MACE HR 0.87 (P=0.01). Established the GLP-1-class cardioprotective paradigm before SUSTAIN-6 (semaglutide) confirmed it.

View term page →LEADER trial deep-dive →

First GLP-1 trial dedicated to chronic kidney disease outcomes. N=3,533 adults with type 2 diabetes + CKD, randomized to semaglutide 1 mg vs placebo (Perkovic 2024 NEJM, PMID 38785209). Primary kidney composite reduced 24% (HR 0.76). Stopped early for efficacy. Drove the January 2025 FDA Ozempic label expansion for kidney-disease progression prevention.

View term page →FLOW trial deep-dive →

Gallstones. Listed in Section 5 of every FDA-approved GLP-1 label. Wegovy reports 1.6% vs 0.7% placebo; Saxenda reports 2.2% vs 0.8%. The He et al 2022 meta-analysis pooled the GLP-1 risk at RR 1.37 (95% CI 1.23-1.52).

View term page →GLP-1 + gallbladder/biliary disease →

Functional bowel obstruction. Added to Section 6.2 (Postmarketing Experience) of every GLP-1 label in 2023. Sodhi JAMA 2023 cohort found HR 4.22 for bowel obstruction; the Ueda Scandinavian cohort 2024 found HR 0.83 — evidence is mixed.

View term page →GLP-1 + ileus / bowel obstruction →

Diffuse hair shedding triggered by rapid weight loss or metabolic stress. Typically self-resolving over 3-6 months with adequate protein and micronutrient intake.

View term page →GLP-1 fatigue + hair loss + duration →

Patient term for facial volume loss with rapid weight loss on a GLP-1. The 2025 Otolaryngology imaging cohort (PMID 40407186) quantified it at median 9% midfacial volume loss with about 7% loss per 10 kg total weight lost.

View term page →Ozempic face: facial volume loss evidence →

Rare neuroendocrine tumor of thyroid C-cells. GLP-1 medications carry a black-box warning based on rodent data; no increased human MTC incidence has been demonstrated. Contraindicated in patients with personal/family history of MTC or MEN-2.

View term page →Does GLP-1 cause cancer? MTC evidence →

Loss of muscle, bone, and other non-fat tissue with rapid weight loss. STEP-1 DEXA sub-analysis found roughly 39% of weight lost was lean mass. Mitigated with adequate protein and resistance training.

View term page →Semaglutide and muscle mass: STEP DEXA sub-analyses →

Delayed gastric emptying severe enough to cause persistent nausea, vomiting, or food retention after a GLP-1 dose. A 2023 JAMA case-control study (PMID 37335445) found GLP-1 use associated with a 3.7-fold increased risk of clinically diagnosed gastroparesis vs bupropion-naltrexone. Risk rises with higher doses, faster titration, and pre-existing diabetic autonomic neuropathy. Symptoms usually resolve within 4-8 weeks of dose reduction or discontinuation.

View term page →Side-effect timeline tool →

Inflammation of the pancreas, listed as a labeled warning for every approved GLP-1 receptor agonist. Mechanism is uncertain but appears to involve cholelithiasis-triggered duct obstruction rather than direct pancreatic toxicity. Pooled FDA AERS data shows incidence ~0.2-0.4% over typical treatment durations — elevated vs background ~0.05%/year but absolute risk remains low. Patients with prior pancreatitis, heavy alcohol use, or symptomatic gallstones should weigh risk:benefit carefully.

View term page →Side-effect timeline tool →

An early concern from rodent studies (acinar-cell hyperplasia in some animal models). Large human cohort studies and the SELECT cardiovascular outcomes trial (Lincoff 2023, PMID 37952131) have NOT shown an elevated pancreatic-cancer signal over years of follow-up. The 2024 FDA Drug Safety Communication confirmed no causal association established. The boxed warning on GLP-1 labels covers thyroid C-cell tumors (rodent data) and acute pancreatitis (small absolute risk), but NOT pancreatic cancer.

View term page →SELECT trial deep-dive (long-term safety) →

Localized swelling or thickening of subcutaneous fat at recurrently-used injection sites — common in patients who inject GLP-1s in the same spot weekly. Lipohypertrophic tissue absorbs the drug erratically, causing unpredictable appetite suppression and weight-loss outcomes. Prevention: rotate at least 2 inches between consecutive doses, cycling abdomen → thigh → upper arm over 8 weeks.

View term page →Injection-site rotation cheat sheet →

Prescription GLP-1 medications prepared from bulk active ingredient by a 503A or 503B pharmacy rather than the FDA-approved branded product. Legality and quality vary; FDA-approved products are off the shortage list as of late 2024.

View term page →Compounded semaglutide bioequivalence →

Traditional state-licensed compounding pharmacy that prepares medications for individual patients with a prescription. Subject to USP <797> standards but not FDA pre-approval of finished products.

View term page →PCAB accreditation investigation →

FDA-registered facility licensed to compound medications without a patient-specific prescription, in larger volumes than a 503A. Subject to FDA inspection and stricter quality oversight than 503A.

View term page →PCAB accreditation investigation →

Pharmacy Compounding Accreditation Board certification, administered by ACHC. A voluntary third-party quality program covering sterility, potency verification, and facility standards. Required for some 503B outsourcing facilities.

View term page →PCAB accreditation investigation →

The United States Pharmacopeia chapter governing sterile compounding for human use, covering air quality, personnel garbing, surface sampling, and beyond-use dating for compounded preparations. 503A pharmacies must demonstrate USP <797> compliance to dispense sterile injectables like compounded semaglutide. Inspections typically check ISO Class 5 primary engineering controls, anteroom pressure differentials, and operator media-fill testing.

View term page →Pharmacy legitimacy lookup tool →

Two FDA categories for sterile compounding pharmacies. 503A: state-licensed pharmacies that compound patient-specific prescriptions (must hold a valid prescription with a named patient). 503B: voluntarily-registered outsourcing facilities that can compound in bulk without prescriptions, must comply with full Current Good Manufacturing Practice (cGMP) standards.

View term page →Compounded vs brand Q&A hub →

Formal FDA enforcement document citing specific regulatory violations and demanding corrective action. We track every warning letter sent to compounded GLP-1 telehealth providers and pharmacies.

View term page →FDA warning letters to GLP-1 providers (live database) →

Insurance requirement that a prescriber submit clinical justification before a medication will be covered. Common for GLP-1 weight-loss drugs given the high list price; turnaround typically 24-72 hours.

View term page →GLP-1 prior auth letter generator (tool) →

Insurance requirement to try cheaper or older medications before authorizing newer/more expensive options. A common access barrier for GLP-1 weight-loss drugs.

View term page →GLP-1 insurance coverage: Medicare, Medicaid, commercial →

Prescribing an FDA-approved drug for a condition or population not on its label. Legal and common — Ozempic for weight loss is the canonical example. Insurance coverage may not extend to off-label indications.

View term page →How to get a GLP-1 prescription →

Public FDA database tracking medications in short supply. Compounded GLP-1s were widely produced under the shortage exemption while semaglutide and tirzepatide were on the list (off the list as of late 2024).

View term page →Compounded GLP-1 price movement (12-month analysis) →

The cost-share level a prescription drug occupies in an insurance plan's formulary (covered drug list). Tier 1 = generic ($), Tier 2 = preferred brand ($$), Tier 3 = non-preferred brand ($$$), Tier 4 = specialty (highest copay). Wegovy and Zepbound are typically Tier 3 or 4 on commercial plans — meaning copays of $100-$500+/month even after approval. Some plans exclude them entirely. Generic GLP-1s do not yet exist (semaglutide patent runs through 2032 in the US).

View term page →Insurance coverage Q&A hub →

Gradual dose escalation to minimize side effects. Tirzepatide's standard schedule steps every 4 weeks (2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg). Slower titration reduces nausea and the rate of facial volume change.

View term page →GLP-1 titration planner (tool) →

Time for plasma concentration to fall by half. Semaglutide ~7 days. Tirzepatide ~5 days. Liraglutide ~13 hours (daily dosing). Orforglipron ~36 hours. Determines weekly vs daily dosing and washout timing.

View term page →How long does a GLP-1 stay in your system →

Time between stopping one GLP-1 and starting another (or before pregnancy planning). The Wegovy label recommends discontinuing at least 2 months before a planned pregnancy.

View term page →GLP-1 washout calculator (tool) →

Skipped weekly injection. For semaglutide and tirzepatide: take within 5 days of the missed dose; if more than 5 days have passed, skip the missed dose and resume the schedule.

View term page →GLP-1 missed-dose guide (tool) →

Stalling weight loss after months of progress. Mechanisms include metabolic adaptation, behavior drift, and dose ceiling. Often resolves with re-titration, dietary review, or resistance training.

View term page →Why am I not losing weight on a GLP-1? →

Off-label use of sub-therapeutic GLP-1 doses to minimize side effects or extend supply. Limited evidence; the published RCT data was conducted at the FDA-approved doses.

View term page →Semaglutide microdosing evidence →

Moving from one GLP-1 to another (e.g., semaglutide to tirzepatide). Generally requires re-titration; the prior drug's washout time and the new drug's titration plan both matter.

View term page →Switching between GLP-1 medications guide →

Rapid regain of body weight following GLP-1 discontinuation. The STEP-1 withdrawal extension (Wilding 2022 Diabetes Obes Metab, PMID 35441470) showed participants who stopped semaglutide 2.4 mg after 68 weeks regained two-thirds of their lost weight within one year, with restoration of pre-treatment metabolic risk markers. The data reframed GLP-1 obesity treatment as chronic-disease therapy, like blood-pressure medication, rather than a finite intervention.

View term page →STEP-1 withdrawal extension on our top studies list →

The American Society of Anesthesiologists 2023 guidance recommends holding daily GLP-1s for 1 day and weekly GLP-1s for 1 week before procedures requiring anesthesia, due to elevated aspiration risk from delayed gastric emptying. Updated 2024 guidance is less strict (hold not strictly required if NPO ≥18 hours and clinical judgment supports proceeding). Endoscopy patients on GLP-1s have ~6× increased rate of retained gastric contents.

View term page →Side-effect timeline tool →

Injection into the fatty layer just below the skin (not into muscle). All FDA-approved injectable GLP-1 receptor agonists — Wegovy, Ozempic, Zepbound, Mounjaro, Saxenda, Victoza, Trulicity — use subq dosing. Approved injection sites: abdomen (≥2 inches from the navel), front of thigh, or back of upper arm. Rotate weekly to reduce lipohypertrophy. Inject at room temperature for less discomfort.

View term page →Wegovy dose-ladder cheat sheet →

All approved GLP-1 receptor agonists carry a pregnancy precaution and are recommended to be discontinued at least 2 months (semaglutide, given its long half-life) before a planned conception. Animal studies show developmental toxicity at human-equivalent doses. No randomized human-pregnancy data exist; observational registries are accumulating. Patients of reproductive age should use reliable contraception. Inadvertent GLP-1 exposure in early pregnancy is not a guaranteed indication for termination — discuss with a maternal-fetal medicine specialist.

View term page →Wegovy cheat sheet (red flags) →

Structured weight-management counseling delivered by a registered dietitian or qualified clinician — typically 30 visits over 12-14 months, with a target of 1,000-1,500 kcal/day diet + ≥200 min/week physical activity. Required adjunct in some insurance prior-authorization criteria for Wegovy and Zepbound. STEP-3 (semaglutide + IBT) and SURMOUNT-3 (tirzepatide + IBT) showed GLP-1s and IBT are additive, not redundant.

View term page →STEP-3 trial deep-dive →