Visual Guide to Mounjaro Pens: What Do Mounjaro Pens Look Like?

Last reviewed: July 10, 2026

Last updated: July 10, 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.

Mounjaro pens deliver tirzepatide, a dual GLP-1/GIP receptor agonist approved by the FDA for type 2 diabetes and weight loss. The injectable device has become recognizable in medical settings, but many patients starting treatment want to know exactly what they'll be handling each week. This visual guide walks you through the pen's design, components, and practical features.

Mounjaro Pen Exterior Design and Color

The Mounjaro pen displays a striking teal (blue-green) and gray color combination that makes it instantly identifiable in a medicine cabinet. The barrel of the pen is cylindrical and measures approximately 4.5 inches in length, roughly the size of a standard marker or highlighter. The top portion features the gray dose selector dial, while the lower section transitions to the signature teal shade that Eli Lilly uses across its GLP-1 product line.

The pen's exterior surface has a matte finish designed to provide a secure grip during the injection process. The width accommodates most adult hands comfortably, and the balanced weight distribution prevents strain during weekly self-injection. The device arrives pre-filled with medication and is not reusable, meaning patients receive a new pen each week of their treatment cycle.

Key Components of the Mounjaro Injection Device

At the top of the Mounjaro pen sits a removable gray cap that protects the injection needle before use. Directly beneath this cap lies the needle itself, which is extremely thin (a 31-gauge needle) to minimize injection discomfort. The needle retracts automatically after injection, reducing the risk of accidental needle sticks and providing a safety feature that many patients appreciate.

The large dial on the front of the pen is perhaps its most distinctive feature—it displays dose numbers in milligrams, rotating from 0.25 mg to 15 mg in increments of 0.25 mg. This dial turns with audible and tactile clicks, allowing patients to select their prescribed dose with clear feedback. At the bottom of the pen is the activation button, which patients press to deliver the medication after dialing their dose.

How the Mounjaro Pen Functions During Injection

Before using a Mounjaro pen, patients must remove the gray protective cap from the needle end. Next, they rotate the large dose dial to their prescribed weekly dose—a process that typically takes 3–5 seconds and provides satisfying tactile confirmation with each click. After selecting the correct dose, patients apply the pen to their chosen injection site (typically the abdomen, thigh, or upper arm) and press the activation button at the base until they hear a clicking sound indicating the injection has started.

The entire injection process lasts 5–9 seconds, during which the medication flows through the ultra-fine needle into the subcutaneous tissue. Once the mechanism completes, patients hear a second clicking sound signaling the dose has been fully delivered and the needle has automatically retracted into the pen. This automatic safety feature eliminates the need for manual needle withdrawal and reduces contamination risk.

PlexusDx Compounded Tirzepatide vs. Brand Mounjaro Pens

PlexusDx offers compounded tirzepatide injection through licensed 503A compounding pharmacies, providing access to the same active medication at a starting price of $289 per month without flat per-compound pricing increases. While Mounjaro pens feature the distinctive teal-and-gray design described above, compounded tirzepatide may arrive in different delivery formats depending on the pharmacy and patient preference—including standard syringes, insulin pens, or other injection devices. Both options deliver the identical tirzepatide molecule and work through the same GLP-1/GIP receptor pathway to reduce appetite and improve metabolic function.

The key practical difference lies in accessibility and cost. PlexusDx serves all 50 states without requiring insurance, membership fees, or prior authorizations, and compounded options are HSA/FSA eligible. Patients who choose PlexusDx can also add the Precision Peptide Genetic Test ($99 after the first month) to identify genetic predispositions in the GLP1R, GIPR, FTO, and MC4R pathways—insights that help optimize individual response to tirzepatide therapy. Whether patients use brand Mounjaro pens or compounded tirzepatide, the clinical mechanism and weight-loss effectiveness remain consistent.

How Your Genetics Relate to GLP-1 Pathways

Not everyone responds to GLP-1 medications the same way. Genetic variants — including GIPR rs1800437, GLP1R rs6923761, 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 ($99 add-on after your first month of treatment) 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 six prescription GLP-1 protocols to all 50 states — no membership, no insurance required, async intake or live consult. The Tirzepatide Injection starts at $289/mo. Medications are dispensed from licensed 503A compounding pharmacies following strict quality and safety standards. Add a Precision Peptide Genetic Test for $99 to personalize your protocol from day one.

Frequently Asked Questions

What color are Mounjaro pens and how do I identify them?

Mounjaro pens display a distinctive teal and gray color scheme with a large dial mechanism on the front. The teal barrel and gray dose selector make the pen easily recognizable once you've seen it, and the familiar appearance helps many patients feel confident during their weekly injection routine.

How much medication does a Mounjaro pen hold?

Each Mounjaro pen is pre-filled with a single dose only—you cannot reuse the pen or refill it. After your weekly injection, you discard the pen and use a new one the following week, making it a convenient single-use device designed for simplicity and safety.

Is the Mounjaro needle painful, and how thin is it?

Mounjaro uses a 31-gauge needle, one of the thinnest needle sizes available for subcutaneous injection, which minimizes discomfort for most patients. The needle automatically retracts after injection, providing both safety and reducing anxiety about manual needle handling that some patients experience.

Does PlexusDx offer compounded tirzepatide, and will my price increase with higher doses?

Yes, PlexusDx offers compounded tirzepatide injection starting at $289/mo (or $249/mo on the 6-month plan) through licensed 503A compounding pharmacies available in all 50 states. Your dose may need to go up as your body adjusts, but your price won't—PlexusDx uses flat monthly pricing regardless of dose level, with no insurance required and HSA/FSA eligibility.

How does the Precision Peptide Genetic Test relate to your GLP-1 pathway?

PlexusDx's Precision Peptide Genetic Test identifies your natural variations in GLP1R, GIPR, FTO, and MC4R pathways, which influence individual response patterns to tirzepatide therapy. Available for $99 after your first month of treatment, this test maps 14 metabolic pathways and 49 peptides to help personalize your weight-loss strategy beyond simple dose adjustment.

Related Reading

• Hers Mounjaro
• Hims Mounjaro
• Mounjaro For Hypertension
• Mounjaro For Endometriosis

Pricing and availability current as of July 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.