GLP-1 weight loss glossary
63 terms you'll meet while comparison-shopping the US weight loss telehealth category. Plain definitions, no filler.
5
503A pharmacy
A compounding pharmacy regulated under section 503A of the Federal Food, Drug and Cosmetic Act. 503A pharmacies prepare medications individually based on a prescription for a specific patient, under state board of pharmacy oversight rather than FDA new-drug approval. Most compounded GLP-1s in 2026 are prepared at 503A pharmacies.
503B outsourcing facility
A larger compounding facility regulated under section 503B. Unlike 503A, 503B facilities can compound in bulk without individual prescriptions and are subject to FDA cGMP-like inspections. Few 503Bs compound GLP-1s due to bulk-volume regulatory complexity.
A
Abbreviated New Drug Application (ANDA)
The FDA pathway by which generic drugs are approved. Generic semaglutide manufacturers must file ANDAs demonstrating bioequivalence with branded Wegovy. The first ANDAs for semaglutide were filed 2024-2025; first approvals expected late 2026.
ABOM (American Board of Obesity Medicine)
The US specialty board that certifies physicians in obesity medicine. ABOM-certified clinicians complete a fellowship or supervised training and pass a board exam. Form Health and Knownwell market themselves as employing ABOM-certified prescribers; most general telehealth programs do not.
Active pharmaceutical ingredient (API)
The biologically active chemical in a medication. Semaglutide and tirzepatide are APIs. Compounded GLP-1s typically source API from FDA-registered manufacturers, but the final compounded product is not FDA-approved as a drug product.
Adherence
How consistently a patient takes a medication as prescribed. Trial efficacy numbers assume high adherence; real-world adherence on GLP-1s runs lower because of dose-titration friction, side effects and supply gaps. Adherence below 80% reduces weight loss roughly proportionally.
All-in pricing
The total monthly cost a patient actually pays, including membership, medication, visits and lab fees, with no add-ons hidden behind a low headline price. Mochi and Henry Meds bundle compounded GLP-1 into an all-in monthly fee; most programs unbundle medication and bill separately.
B
BMI (Body Mass Index)
Weight in kilograms divided by height in meters squared. Most US insurance plans require BMI ≥30 for GLP-1 weight loss coverage, or BMI ≥27 with an obesity-related comorbidity. BMI is a population-level statistic and a poor individual diagnostic, but it is the gate insurance plans use.
Branded drug
A medication marketed under a manufacturer's brand name, FDA-approved as a new drug and protected by patent. Wegovy (Novo Nordisk), Zepbound (Eli Lilly), Ozempic (Novo Nordisk) and Mounjaro (Eli Lilly) are branded drugs. Compounded versions of the same molecules are not.
Bundled pricing
Membership fee and medication cost combined into a single monthly charge. Lower friction for cash-pay patients because the price doesn't change when you titrate up doses. Opposite: unbundled pricing, where membership is one charge and medication is a separate charge that scales with dose.
C
C-cell tumors / MTC
Medullary thyroid carcinoma. Animal studies on liraglutide showed thyroid C-cell tumors in rodents at higher-than-human doses; no human signal has been observed but a boxed warning is included on every GLP-1 label. Patients with a personal or family history of MTC or MEN2 syndrome should not take GLP-1s.
Cardiometabolic
Relating to both cardiovascular disease and metabolic conditions (type 2 diabetes, dyslipidemia, hypertension, obesity). Insurance plans use cardiometabolic risk as a justification for GLP-1 prior-authorization approval at BMI 27 to 29.9. 9amHealth specifically targets cardiometabolic patients.
Cold chain
The refrigerated supply chain required for biologic medications. Branded GLP-1s ship between 2-8°C and must be refrigerated until first use, after which the pen is good at room temperature for up to 28 days. Patients traveling more than 24 hours need an insulated medication cooler with ice packs.
Comorbidity
A medical condition co-occurring with another. For GLP-1 weight loss insurance coverage, common qualifying comorbidities include type 2 diabetes, hypertension, dyslipidemia (high cholesterol) and obstructive sleep apnea.
Compounded medication
A medication prepared at a pharmacy under prescription, customized for a patient or batch. Compounded medications are not FDA-approved as new drugs. The active ingredient may be identical to a branded product, but the regulatory pathway, manufacturing oversight and insurance coverage are not.
Compounded tirzepatide
Tirzepatide prepared by a 503A or 503B compounding pharmacy rather than manufactured by Eli Lilly. Less common than compounded semaglutide because tirzepatide came off the FDA shortage list in October 2024; most 2026 sources are personalized formulations (with added vitamin B12 or other) to remain legally distinct from the FDA product.
CPA (Cost per acquisition)
The amount an affiliate or marketing channel pays for one converted customer. Weight loss program affiliate CPAs in 2026 range from ~$10 (Noom) to ~$300 (WeightWatchers Clinic on annual signups).
Custom formulation / personalized formulation
A compounded medication that includes additional active ingredients (vitamin B12, l-carnitine) beyond the original molecule. Used by 503A pharmacies after a drug comes off the FDA shortage list, to remain legally distinct from copying an FDA-approved product. Same active GLP-1 molecule, regulatory framing different.
D
Direct-to-consumer (DTC)
A distribution model where the manufacturer or program sells directly to patients without an intermediary. NovoCare and LillyDirect are DTC programs from Novo Nordisk and Eli Lilly that sell branded GLP-1s at reduced cash prices.
Dyslipidemia
Abnormal blood lipid levels (high LDL, low HDL, high triglycerides). One of the qualifying comorbidities for GLP-1 prior-authorization approval at BMI 27 to 29.9. Often documented in routine lipid panels at annual physicals.
E
Eli Lilly
American pharmaceutical company that manufactures Mounjaro and Zepbound (tirzepatide). LillyDirect is Lilly's direct-to-consumer cash-pay channel.
Excipient
An inactive ingredient added to a medication for stability, absorption or shelf life. Brand Wegovy and compounded semaglutide have the same active molecule but different excipients, which is why some patients tolerate one and not the other despite identical pharmacology.
F
FDA approval
The US Food and Drug Administration's process for clearing new drugs for sale. Wegovy was approved for chronic weight management in 2021. Compounded versions of approved drugs are not separately FDA-approved as drug products; they exist under separate compounding regulations.
FDA shortage list
A list maintained by the FDA of drugs in officially-declared shortage. While a drug is on the list, 503A pharmacies have broader latitude to compound versions of it. Semaglutide was on the list 2022-2024; tirzepatide briefly in 2024. Both are now off.
Formulary
An insurance plan's list of covered drugs, organized by tier. Wegovy and Zepbound typically sit on Tier 3 or 4 with prior-authorization required. If a drug is not on the formulary at all, the plan does not cover it for any condition.
Foundayo
Found's branded program for compounded orforglipron, Eli Lilly's oral GLP-1 still in pre-launch FDA review. Found prepares orforglipron through 503A pharmacies as it is not yet branded-available.
FSA (Flexible Spending Account)
A tax-advantaged employer-sponsored account for medical expenses. Same eligibility as HSA for GLP-1 weight loss, but FSA balances generally don't roll over year-to-year.
G
Generic drug
A medication chemically identical to a branded drug, manufactured by a non-originator company under FDA approval after the originator's exclusivity has expired. The first generic semaglutide approvals are expected late 2026 to early 2027.
GIP receptor
Glucose-dependent insulinotropic polypeptide receptor. Tirzepatide is a dual GLP-1 + GIP receptor agonist; semaglutide is GLP-1 only. The dual mechanism is the leading theory for tirzepatide's higher mean weight loss in registration trials.
GLP-1 (Glucagon-like peptide-1)
A hormone that slows gastric emptying, promotes satiety and stimulates insulin release. GLP-1 receptor agonists (semaglutide, liraglutide, dulaglutide) and dual GLP-1/GIP agonists (tirzepatide) mimic this hormone for weight loss and diabetes treatment.
Goal weight
The target weight where the active weight-loss phase ends and maintenance begins. It's the decision point: stay on the GLP-1 to hold the loss, or stop and accept a high chance of regain.
H
HSA (Health Savings Account)
A tax-advantaged account for medical expenses, paired with high-deductible insurance plans. GLP-1 weight loss medications and most weight-loss telehealth memberships are HSA-eligible expenses.
I
Insulin resistance
A metabolic state where cells respond less to insulin, common in obesity, prediabetes and PCOS. GLP-1 agonists improve insulin sensitivity independently of weight loss, which is part of why the class works for diabetes and PCOS in addition to obesity.
L
LegitScript
A private compliance certification organization that verifies legitimate online pharmacies and healthcare merchants. Google, Meta and Microsoft require LegitScript Healthcare Certification for GLP-1 advertising. Most major US weight-loss telehealth programs carry it.
LillyDirect
Eli Lilly's direct-to-consumer cash-pay channel for Zepbound. Vial format is cheaper than pen format. As of 2026, single-vial Zepbound runs roughly $349 to $549/month depending on dose tier, undercutting most compounded tirzepatide pricing.
Liraglutide
An older GLP-1 receptor agonist marketed as Saxenda for weight loss and Victoza for diabetes. Less effective for weight loss than semaglutide and tirzepatide; mostly displaced by them.
Lock-in / commitment
A term in a subscription contract requiring the patient to remain enrolled for a defined period. A handful of the 25 programs in our chart use 6-month or 12-month locks; most are month-to-month.
M
Maintenance dose
The dose a patient stays on long-term after reaching goal weight. Some patients maintain at the maximum dose; others step down to a lower dose. The data on step-down maintenance is thin; the practice is increasingly common but not formally trialed.
Member-reported outcomes
Patient-reported satisfaction and weight-loss data collected outside formal clinical trials. GLP Chart's score includes Trustpilot, Reddit and program-specific community feedback weighted equally. Less rigorous than registration trial data but more representative of real-world adherence.
Microdose protocol
An off-label approach to GLP-1 dosing that starts at a fraction of the standard maintenance dose (e.g., 0.1mg semaglutide instead of 0.25mg) and titrates slowly. Some patients experience fewer GI side effects. Noom Med is the only major program offering a formal microdose protocol.
Microdosing
Taking a GLP-1 at a fraction of the standard maintenance dose, typically 0.1 to 0.25 mg of semaglutide weekly. Off-label, with no clinical-trial support. Popular in 2025-2026 cost-sensitive cohorts trying to extend supply. Real efficacy at microdose is poorly characterised.
Mounjaro
Eli Lilly's branded tirzepatide for type 2 diabetes. Often prescribed off-label for weight loss before Zepbound's 2023 approval; some programs still prescribe it off-label.
N
Novo Nordisk
Danish pharmaceutical company that manufactures Wegovy, Ozempic and Saxenda. Has pursued legal action against compounded semaglutide pharmacies and 2026 telehealth programs distributing compounded products.
NovoCare
Novo Nordisk's direct-to-consumer cash-pay program for Wegovy. Provides discounted cash prices for branded Wegovy without requiring insurance navigation.
O
Off-label prescribing
Prescribing a medication for a condition different from its FDA-approved indication. Ozempic is FDA-approved for diabetes but commonly prescribed off-label for weight loss. Mounjaro for weight loss before Zepbound's approval was also off-label.
Orforglipron
Eli Lilly's oral GLP-1 receptor agonist still in late-stage FDA review for branded approval in 2026. Found's Foundayo program prepares orforglipron through 503A pharmacies as branded approval is pending.
Ozempic
Novo Nordisk's branded semaglutide injectable for type 2 diabetes (lower doses than Wegovy). Often prescribed off-label for weight loss when Wegovy is unavailable or uncovered by insurance.
P
Patent cliff
The point at which a pharmaceutical patent expires and generic competition can enter the market. Semaglutide's primary patent expires in 2032 in the US, after which ANDA generics will likely launch. Branded prices typically fall 70 to 90% within 18 months of patent expiry.
Personalized advertising policy
Google Ads and Meta Ads policies restricting use of sensitive personal categories (including specific health conditions) for ad targeting. Practical effect: GLP-1 advertisers cannot target keywords containing drug names without LegitScript Healthcare Certification.
Prior authorization (PA)
An insurance plan's requirement that a prescription be reviewed before coverage is approved. For GLP-1 weight loss, PA typically requires BMI documentation, comorbidity attestation and sometimes evidence of prior failed lifestyle interventions. Approval timeline: 3-14 business days.
R
Refill cadence
How often a patient orders new medication. Most telehealth programs default to monthly auto-shipment; some allow quarterly bulk shipping with pharmacy discretion. Cadence affects refrigerator storage planning.
S
Saxenda
Novo Nordisk's branded liraglutide for weight loss. Pre-dates and is less effective than Wegovy. Daily injection rather than weekly. Largely displaced by semaglutide and tirzepatide products.
Semaglutide
The active GLP-1 receptor agonist molecule in Wegovy, Ozempic and Rybelsus. Most-prescribed GLP-1 in the world. Subject of compounded prescribing 2022-2026; FDA shortage status resolved October 2024.
Sequence
Original brand name of WeightWatchers Clinic. Acquired by WeightWatchers in 2023 and rebranded.
Step therapy
An insurance plan's requirement that a patient try and fail a cheaper drug before the plan will cover a more expensive one. For GLP-1 weight-loss PA, the cheaper drug is often phentermine, naltrexone-bupropion or orlistat. Documenting the failure requires 4 to 12 weeks of supervised trial.
Stockpiling
Buying and storing more medication than current use requires, usually as a hedge against supply disruption or price increase. Stockpiling compounded GLP-1 carries clinical risk (cold-chain breaks) and regulatory risk (some state pharmacy boards interpret it as resale). Stockpile no more than 90 days at a time.
T
Telehealth
Healthcare delivery via telecommunications technology, typically video or asynchronous messaging. All weight loss programs in our chart are primarily telehealth-delivered, with no in-person visits required for most patients.
Tirzepatide
Eli Lilly's dual GLP-1/GIP receptor agonist molecule, in branded Mounjaro (diabetes) and Zepbound (weight loss). Generally produces greater weight loss than semaglutide in head-to-head trials.
Titration
The process of gradually increasing a medication dose to the therapeutic level while monitoring tolerance. Standard GLP-1 titration moves up monthly: 0.25 → 0.5 → 1.0 mg for semaglutide; 2.5 → 5 → 7.5 mg for tirzepatide. Skipping titration steps causes worse side effects without better efficacy.
Trustpilot
An open online review platform. We use Trustpilot scores as one input to our member-reported outcomes dimension, weighted alongside Reddit sentiment and program-specific community feedback.
W
Wegovy
Novo Nordisk's branded semaglutide injection FDA-approved for chronic weight management. The first GLP-1 approved specifically for obesity. Sold at $1,300/mo retail or $149-$299/mo via NovoCare cash.
WHO-GMP
World Health Organization Good Manufacturing Practice certification, a manufacturing quality standard recognized by regulators globally. The standard most non-FDA international generic manufacturers operate under.
Z
Zepbound
Eli Lilly's branded tirzepatide injection FDA-approved for chronic weight management. Sold at ~$1,100/mo retail or $299-$449/mo via LillyDirect cash, depending on dose and presentation (vials vs pens).
