What Drugs Are GLP-1 Inhibitors? A Comprehensive Guide

Last reviewed: June 5, 2026

Last updated: June 5, 2026

Written by: Jay Hastings, CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

This article is part of the PlexusDx Education Hub — science-backed guidance on GLP-1 medications, metabolic health, and precision weight management.

GLP-1 receptor agonists are medications that mimic glucagon-like peptide-1, a natural hormone that regulates hunger and blood sugar. Originally developed for type 2 diabetes, these drugs have shown remarkable effectiveness for weight management, with clinical trials demonstrating weight loss of 15–22% in patients receiving higher doses. PlexusDx provides access to compounded GLP-1 inhibitors tailored to your body's genetic response to peptide therapy.

What Are GLP-1 Inhibitor Medications?

GLP-1 inhibitors are synthetic versions of a hormone your body naturally produces in the intestines. When you eat, your gut releases GLP-1 to signal your brain that you are full, slowing stomach emptying and reducing food cravings. These medications bind directly to GLP-1 receptors in the brain and pancreas, amplifying these satiety signals and improving how your body processes glucose.

The medication class includes semaglutide, tirzepatide, and other compounds that work through similar but distinct mechanisms. Semaglutide activates GLP-1 receptors primarily, while tirzepatide targets both GLP-1 and glucose-dependent insulinotropic peptide (GIP) receptors, often producing greater weight loss in clinical studies. PlexusDx offers both as compounded injections or oral formulations, allowing you to choose the delivery method that fits your lifestyle.

Main GLP-1 Inhibitor Drugs Available Today

Semaglutide is one of the most widely recognized GLP-1 inhibitors, originally marketed for diabetes and later approved for chronic weight management. PlexusDx provides compounded semaglutide injection at $189/mo month-to-month, or from $149/mo on the 6-month plan through licensed 503A compounding pharmacies, with no insurance requirement. This medication is administered weekly via subcutaneous injection and has demonstrated consistent, dose-responsive weight loss across multiple clinical trials.

Tirzepatide represents a newer generation of GLP-1 inhibitors with dual-receptor activation, combining GLP-1 and GIP agonism into a single compound. Clinical evidence shows tirzepatide produces numerically greater weight loss compared to semaglutide alone, with PlexusDx offering compounded tirzepatide injection at $289/mo month-to-month, or from $249/mo on the 6-month plan. For patients seeking maximum flexibility, PlexusDx also offers GLP-Squared Injection, a dual-compound formulation combining both semaglutide and tirzepatide, at $289/mo month-to-month, or from $249/mo on the 6-month plan.

Oral versions of both medications are available for those who prefer tablets to injections. PlexusDx compounded oral semaglutide is $289/mo month-to-month (or $249/mo on the 6-month plan), while oral tirzepatide is $349/mo month-to-month, or from $279/mo on the 6-month plan. The Precision Peptide Genetic Test, available as $298, helps describe the pathway-level variants involved.

How GLP-1 Inhibitors Work in Your Body

GLP-1 inhibitors operate through multiple physiological pathways that work together to reduce weight and stabilize blood sugar. In the brain, they activate receptors in the hypothalamus that control appetite, increasing feelings of fullness after smaller meals and reducing hunger between meals. Simultaneously, these medications slow gastric emptying—the rate at which food moves from your stomach into your small intestine—creating lasting satiety.

Beyond appetite suppression, GLP-1 inhibitors improve insulin secretion in response to meals, helping your body manage blood glucose more effectively. They also promote a modest increase in resting energy expenditure and may favorably alter how your body distributes fat stores. These multiple mechanisms explain why GLP-1 inhibitors are so effective across diverse patient populations, though individual response varies based on genetics, lifestyle, and baseline metabolic health.

The PlexusDx Precision Peptide Genetic Test analyzes GIPR (rs1800437) — variants that relate to GLP-1 and related signaling pathways. It does not predict your response to tirzepatide or determine your dose; it offers pathway-level context for a conversation with your provider. Genetics is a guide, not a guarantee.

Choosing Between Injection and Oral GLP-1 Inhibitors

PlexusDx offers both injectable and oral formulations of GLP-1 inhibitors, each with distinct advantages. Injectable medications, administered once weekly, typically achieve higher systemic concentrations and faster onset of action, making them the standard choice for maximum weight loss results. Oral formulations provide convenience for patients who prefer avoiding needles, though they require specific timing and stomach conditions to optimize absorption.

The choice between injection and oral depends on your lifestyle preferences, adherence patterns, and treatment goals. Injections offer the advantage of once-weekly dosing with proven efficacy in large clinical trials, while oral options provide discreet daily or multi-daily dosing. PlexusDx supports both pathways with no price differentiation based on delivery method—your dose may need to go up, but your price won't. The Precision Peptide Genetic Test can also inform which delivery method pairs best with your genetic response profile.

Clinical Evidence Supporting GLP-1 Inhibitor Effectiveness

Large randomized controlled trials have established GLP-1 inhibitors as highly effective for weight management and metabolic improvement. The SUSTAIN and STEP trial series demonstrated that semaglutide produces weight loss of 10–22% depending on dose and duration of treatment, with benefits extending to cardiovascular health markers. Tirzepatide trials showed numerically superior weight loss, with some participants achieving 20%+ reduction in body weight over 72 weeks.

Beyond weight loss, clinical evidence shows GLP-1 inhibitors improve blood pressure, lipid profiles, and insulin sensitivity in most users. Meta-analyses confirm that these medications reduce appetite-related hormones like ghrelin while elevating satiety signals, creating a durable biological shift in hunger regulation. PlexusDx leverages this evidence base by offering access to the same medications used in clinical research, compounded to pharmaceutical standards through licensed 503A pharmacies serving all 50 states.

How Your Genetics Relate to GLP-1 Pathways

Not everyone responds to GLP-1 medications the same way. Genetic variants — including GIPR rs1800437, FTO rs9939609, and MC4R rs17782313 — relate to the biological pathways these medications act on. These are pathway-level associations only and do not predict how much weight you will lose or how you will respond to any specific medication. PlexusDx maps 14 pathways, 49 peptides, and 150+ genetic insights so you and your provider can see how your genes relate to these pathways. It does not recommend, prescribe, or determine which medication, dose, or peptide is right for you. The PlexusDx Precision Peptide Genetic Test ($298) gives you and your provider pathway-level genetic context to support a more personalized conversation. Genetics is a guide, not a guarantee.

Access Personalized GLP-1 Care Through PlexusDx

PlexusDx offers seven prescription GLP-1 protocols to all 50 states — no membership, no insurance required, async intake or live consult. The Semaglutide Injection is $189/mo month-to-month, or from $149/mo on the 6-month plan. Medications are dispensed from licensed 503A compounding pharmacies following strict quality and safety standards. Add a Precision Peptide Genetic Test for $298 to personalize your protocol from day one.

Frequently Asked Questions

What is the difference between GLP-1 inhibitors and other weight loss medications?

GLP-1 inhibitors work by mimicking a natural hormone that regulates hunger and blood sugar, making them distinct from older appetite suppressants or lipase inhibitors. Unlike stimulant-based weight loss drugs, GLP-1 inhibitors produce satiety through biological hormone signaling rather than central nervous system stimulation, generally with fewer side effects and more durable results. PlexusDx offers compounded GLP-1 inhibitors that work through this proven mechanism, available in multiple formulations to suit your preferences.

Do all GLP-1 inhibitors work the same way?

While all GLP-1 inhibitors activate GLP-1 receptors, semaglutide and tirzepatide differ in their receptor target profile. Semaglutide is a pure GLP-1 receptor agonist, while tirzepatide also activates GIP receptors, producing a dual-mechanism effect that often delivers greater weight loss in clinical trials. PlexusDx offers both single-compound options and a GLP-Squared dual-compound injection, allowing you to access the mechanism that best matches your genetic response and treatment goals.

How much do PlexusDx GLP-1 inhibitor treatments cost?

PlexusDx compounded semaglutide injection is $189/mo month-to-month (or $149/mo on the 6-month plan), while tirzepatide injection is $289/mo month-to-month, or from $249/mo on the 6-month plan. Oral formulations are also available, with oral semaglutide at $289/mo month-to-month, or from $249/mo on the 6-month plan and oral tirzepatide at $349/mo (or $279/mo on the 6-month plan). No insurance is required, treatments are HSA/FSA eligible, and there is no membership fee—your dose may increase over time, but your price remains flat with PlexusDx.

Are there side effects I should know about with GLP-1 inhibitors?

Common side effects include mild nausea, constipation, or diarrhea during dose escalation phases, which typically diminish as your body adjusts. Most patients tolerate GLP-1 inhibitors well, with serious adverse events being rare in clinical trials. Discuss your medical history and current medications with your PlexusDx provider to ensure GLP-1 inhibitor therapy is appropriate for you; contraindications include personal or family history of medullary thyroid cancer or multiple endocrine neoplasia.

How does the Precision Peptide Genetic Test help me choose a GLP-1 inhibitor?

No — the Precision Peptide Genetic Test does not predict your response to tirzepatide or any specific medication. It analyzes pathway-level variants (GIPR, FTO, and MC4R) that relate to the biology involved, offering context for a conversation with your provider rather than a prediction.

Related Reading

• History Of Glp 1 Drugs Plexusdx
• Glp 1 Agonist Drugs
• Glp 1 Drugs List
• Drugs Glp 1

Pricing and availability current as of June 2026. Compounded GLP-1 medications are not FDA-approved drug products; they are prepared by licensed compounding pharmacies under federal compounding regulations. Compounded semaglutide and tirzepatide are not the same as Wegovy, Ozempic, Zepbound, or Mounjaro. This article is for informational purposes only and does not constitute medical advice. Consult a licensed healthcare provider before starting, stopping, or changing any medication.

Return to the PlexusDx Education Hub for more evidence-based resources on GLP-1 therapy, metabolic health, and personalized weight management.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.