What is GLP-1? Understanding medications, evidence, safety, and provider options

What GLP-1 drugs are and how they work

GLP-1 (glucagon-like peptide-1) receptor agonists mimic a gut hormone that increases insulin secretion in response to meals, slows gastric emptying, and can reduce appetite. Clinically, GLP-1 receptor agonists are prescribed for type 2 diabetes and-at specific doses and approved indications-for chronic weight management. Different molecules and formulations exist; some are approved by the U.S. Food and Drug Administration (FDA) for diabetes, some for weight management, and others may be compounded or sold without FDA approval. It's important to distinguish FDA-approved brand medications from compounded or unapproved products.

• GLP-1 agonists affect blood sugar, appetite, and stomach emptying.
• FDA approval varies by drug and indication (diabetes vs. weight management).
• Compounded or unapproved GLP-1 products carry specific regulatory and safety concerns.

FDA-approved brands vs. compounded and unapproved products

FDA-approved GLP-1 drugs come with prescribing information that lists indications, dosing schedules, contraindications, boxed warnings (if any), and adverse reactions. For example, Wegovy (semaglutide) and Zepbound (tirzepatide) each have prescribing information documents that clinicians use to guide safe prescribing. Compounded products are made by pharmacies to create formulations not commercially available; they are not FDA-approved, may lack standardized dosing, and have been the subject of safety alerts. The FDA has warned that some unapproved GLP-1 products are being marketed or sold for weight loss with incorrect or unclear labeling and dosing, and that such products can cause dosing errors and adverse events.

• Consult the drug's official prescribing information for approved uses, dosing, and warnings (e.g., Wegovy, Zepbound).
• Compounded or unapproved products are not the same as FDA-approved branded medications.
• The FDA has issued specific concerns and alerts about unapproved GLP-1 products being marketed to consumers.

What the major trials show about weight loss effectiveness

Large randomized trials demonstrate that some GLP-1 and related drugs produce substantial average weight loss compared with placebo in adults with overweight or obesity when used with lifestyle interventions. For semaglutide, the STEP 1 trial found that semaglutide 2.4 mg produced materially greater average weight loss than placebo at 68 weeks in adults with overweight or obesity. For tirzepatide, the SURMOUNT-1 trial found that tirzepatide produced large average weight reductions versus placebo at 72 weeks. These trials enrolled specific populations under controlled conditions; actual results in community practice can vary. There are also cardiovascular outcomes trials-such as SELECT for semaglutide-that provide context on cardiovascular effects in selected populations with established cardiovascular disease and overweight or obesity.

• STEP 1: semaglutide 2.4 mg showed greater mean weight loss vs placebo at 68 weeks (see published trial).
• SURMOUNT-1: tirzepatide showed large mean weight reductions vs placebo at 72 weeks (see published trial).
• SELECT: a cardiovascular outcomes trial that informs cardiovascular safety context for semaglutide in selected adults.

Common side effects, contraindications, and boxed warnings

GLP-1 medications commonly cause gastrointestinal side effects including nausea, vomiting, diarrhea, and constipation, particularly during dose escalation. Prescribing information documents list contraindications and adverse reactions; some GLP-1 drugs also carry boxed warnings that clinicians must consider when prescribing. For specific medicines, consult their official prescribing information to review boxed warnings, contraindications, and full adverse reaction profiles before use. The FDA has additionally emphasized safety risks from unapproved products, including dosing errors and adverse events.

• Gastrointestinal symptoms are the most common adverse effects.
• Review each brand's prescribing information for contraindications and boxed warnings (e.g., Wegovy, Zepbound).
• Unapproved products have added safety concerns and have prompted FDA alerts.

Cost: medication price vs membership or platform fees

Cost has two main parts: the medication price (what the drug itself costs, which varies by brand, dose, and insurer coverage) and any membership or platform fees charged by telehealth services or clinics. Brand, FDA-approved GLP-1 medications have manufacturer prices and may be covered by some insurers under medical or pharmacy benefits depending on the indication; compounded or unapproved products may be priced differently but carry higher regulatory and safety risk. Separating medication cost from platform or membership fees is important when comparing options. This guide does not provide specific price figures; consult pharmacies, insurers, and service providers for current pricing and coverage information.

• Medication cost and membership/platform fees are separate expense categories.
• Insurance coverage depends on the drug, indication, and payer policies.
• Do not assume compounded or unapproved products are cheaper once risk and lack of standardized dosing are considered.

Choosing a provider or platform: questions to ask

When comparing clinicians, telehealth platforms, or pharmacies, ask direct questions to assess safety, expertise, and ongoing care plans. Key questions include whether the provider will: review your full medical history and current medications, order or review required baseline and follow-up tests, discuss FDA-approved versus compounded/unapproved products and their risks, explain dosing escalation plans and common side effects, provide blood glucose monitoring instructions if you have diabetes or use other glucose-lowering drugs, and outline costs (medication vs platform fees) and follow-up frequency. Also ask who will manage adverse effects and how to get urgent help if needed.

• Will the clinician review your complete medical history and medications in person or via telehealth?
• Which specific brand and formulation will be prescribed-an FDA-approved product or a compounded product?
• What baseline tests and follow-up monitoring are required (e.g., blood glucose, kidney function) and who orders them?
• How are side effects managed, and who is your point of contact for problems?
• What are the medication costs vs any membership or platform fees, and what does insurance cover?

Safety and regulatory red flags to watch for

The FDA has warned about unapproved GLP-1 products that are being marketed and sold to consumers, sometimes labeled for 'research use only' or 'not for human use' while being offered for weight loss. These products can lead to dosing errors and adverse events. Other red flags include providers who do not review your full medical history, who skip baseline testing, who push compounded or unapproved products without discussing risks, or who refuse to provide an emergency plan for adverse events. Prefer clinicians and pharmacies that reference FDA-approved prescribing information and provide clear documentation.

• Products labeled 'for research' or 'not for human use' but sold for weight loss are a regulatory and safety concern.
• Lack of medical history review, baseline tests, or follow-up is a warning sign.
• Ask for the drug's official prescribing information when a specific brand is recommended.

Practical support: counseling, lifestyle, and tapering expectations

GLP-1 medications are typically prescribed together with lifestyle counseling (dietary guidance, physical activity, and behavioral support) for weight management. Expect dose titration schedules for many agents to reduce side effects; clinicians should explain the escalation plan and what to expect. If stopping therapy, clinicians should discuss how to transition and manage potential weight regain or recurrent appetite changes. Treatment plans are individualized and should be set collaboratively with a qualified clinician.

• Lifestyle counseling complements medication for best outcomes.
• Dose escalation schedules are common and intended to reduce side effects.
• Discuss stopping plans and follow-up to manage potential weight changes.

What to bring to your first appointment

Prepare to provide a complete medical history, current medication list (including over-the-counter and herbal products), insurance information, and any previous records related to weight loss or diabetes care. Ask the clinician to document which specific medication brand and formulation they plan to prescribe, to provide the prescribing information, and to explain necessary laboratory tests and follow-up schedule.

• Full medical history and medication list.
• Insurance and pharmacy benefit information.
• Questions about brand vs compounded products and monitoring plan.

Questions People Ask