Understanding obesity as a chronic disease

Obesity is a complex, chronic condition with multiple contributing factors. It’s not simply about carrying extra weight—obesity significantly increases the risk of serious health problems, including type 2 diabetes, cardiovascular disease, hypertension, certain cancers, and approximately 200 other conditions. Even individuals with obesity who do not yet have weight-related complications may develop them over time.

In 2013, the American Medical Association officially recognized obesity as a disease. Other leading medical organizations—including the American Association of Clinical Endocrinologists, the American Academy of Family Physicians, the American College of Cardiology, and the American College of Surgeons—have since followed suit.

Obesity earns its disease classification for several reasons:

• Impact on body function: Excess body fat disrupts normal physiological processes.
• Risk factor for other diseases: Obesity substantially raises the risk of type 2 diabetes, heart disease, cancer, and more.
• Metabolic abnormalities: Conditions such as insulin resistance, chronic inflammation, and hormonal imbalances are common.
• Quality of life: Obesity can reduce mobility, contribute to mental health challenges, and lead to social stigma.
• Biological and genetic factors: Genetics and biology play significant roles in appetite regulation, cravings, and calorie metabolism.
• Medical intervention: Effective treatment often requires a combination of lifestyle changes, medication, and sometimes surgery.
• Increased mortality: Obesity is associated with higher mortality rates across populations.

Weight loss can be challenging, in part because obesity affects appetite, satiety, metabolism, and hormonal balance even after pounds are shed. Research suggests that when individuals with obesity or type 2 diabetes lose 10% of their body weight, they may experience a substantial reduction—around 21%—in their cardiovascular disease risk over the following decade compared to those who maintain their weight.

How obesity is diagnosed

Obesity exists on a continuum. The most common diagnostic tool is body mass index (BMI), calculated by dividing weight in kilograms by height in meters squared. In adults, a BMI of 30 kg/m² or higher is classified as obesity. For children and adolescents, age- and sex-specific thresholds are used.

Lifestyle-based approaches—personalized reduced-calorie diets, physical activity, and behavioral counseling—form the foundation of weight management and typically result in 5% to 10% weight reduction. However, only 20% to 40% of people maintain that weight loss long term using diet and exercise alone.

In the past, bariatric surgery was the primary option for sustained weight loss, but fewer than 2% of eligible individuals pursued it. Current guidelines recommend weight-loss medications in combination with diet and exercise for adults with a BMI of 30 or higher, or 27 or higher with weight-related medical conditions.

What is tirzepatide?

Tirzepatide is an injectable medication initially developed to manage type 2 diabetes. It is the first and only approved dual incretin therapy, meaning it activates both glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors. This dual mechanism may help address obesity more comprehensively than single-receptor therapies.

Type 2 diabetes and obesity are closely linked metabolic conditions; over 44% of type 2 diabetes cases worldwide are associated with excess weight. Many medications originally designed for diabetes management are now used to support weight loss in appropriate patients.

How tirzepatide works

To understand tirzepatide, it helps to know a bit about how your body regulates blood sugar and appetite.

The pancreas produces insulin (which lowers blood sugar by moving glucose into cells for energy) and glucagon (which raises blood sugar when needed). After you eat, cells in your small intestine release natural hormones called incretins—including GLP-1 and GIP—that signal the pancreas to release insulin.

Tirzepatide is a synthetic molecule that mimics the action of both GLP-1 and GIP. When administered, it:

• Encourages the pancreas to release insulin and reduces glucagon secretion, helping lower blood sugar.
• Binds to receptors in the stomach, intestines, and brain, reducing appetite, diminishing cravings, and slowing stomach emptying.

Clinical mechanisms and benefits

Tirzepatide may offer the following effects, based on clinical research:

• Suppresses appetite and increases feelings of fullness (satiety)
• Decreases food cravings
• Slows gastric emptying, prolonging satiety
• Supports weight loss
• Increases insulin release and improves insulin sensitivity
• Decreases glucagon release
• Reduces liver fat content
• May help protect bone density and heart function
• Lowers blood sugar (in people with diabetes)
• May reduce blood pressure
• Can improve lipid profiles: reduces LDL (“bad”) cholesterol and triglycerides, and may increase HDL (“good”) cholesterol

It’s important to note that individual responses vary, and tirzepatide is not appropriate for everyone.

Effectiveness: What the research shows

Tirzepatide has been studied in large clinical trials for both type 2 diabetes management and weight loss. In pivotal obesity trials (the SURMOUNT program), participants receiving tirzepatide alongside lifestyle interventions achieved significant weight loss compared to placebo—in some cases, mean reductions exceeding 20% of baseline body weight at higher doses over 72 weeks.

Individual results vary widely based on starting weight, adherence to lifestyle changes, dosing, and other factors. Tirzepatide is not a cure for obesity, and weight regain is possible if the medication is discontinued without ongoing lifestyle support.

Common side effects

The most frequently reported side effects of tirzepatide are gastrointestinal and tend to be most pronounced when starting the medication or increasing the dose. Many people find these effects decrease over time as their body adjusts.

Common side effects include:

• Nausea: Eating smaller, more frequent meals may help.
• Diarrhea: A low-fat, bland diet can reduce symptoms.
• Vomiting: Smaller portions and bland foods are recommended; contact your clinician if you have trouble staying hydrated.
• Constipation: Increase fiber and water intake, and stay physically active.
• Indigestion: Stay upright for about 30 minutes after meals and avoid eating within two hours of bedtime.
• Abdominal pain: Contact your healthcare provider if pain persists.
• Decreased appetite
• Fatigue, headache, dizziness

Tirzepatide slows stomach emptying, which can affect the absorption of other medications. Always inform your clinician about all medications and supplements you take.

Serious risks and contraindications

Like other GLP-1 and dual incretin therapies, tirzepatide carries a boxed warning for the potential risk of thyroid C-cell tumors, based on findings in rodent studies. It is not yet clear whether this risk applies to humans.

Signs of thyroid cancer may include:

• A new lump or mass in the neck
• Difficulty swallowing
• Shortness of breath
• Persistent hoarseness

Tirzepatide should not be used if you have:

• A personal or family history of medullary thyroid carcinoma (MTC)
• Multiple endocrine neoplasia syndrome type 2 (MEN2)
• Known hypersensitivity to tirzepatide

Other serious risks may include:

• Pancreatitis (inflammation of the pancreas)
• Gallbladder disease
• Acute kidney injury
• Hypoglycemia (low blood sugar), especially if combined with insulin or sulfonylureas
• Diabetic retinopathy complications in people with type 2 diabetes
• Accelerated heart rate
• Allergic or hypersensitivity reactions
• Suicidal thoughts or behavior (monitor mood closely)
• Injection site reactions
• Intestinal blockage

Tirzepatide has not been studied in people with a history of pancreatitis and is contraindicated in individuals with type 1 diabetes. Pregnant individuals or those planning to become pregnant should not use tirzepatide, as it may cause fetal harm.

If you experience severe abdominal pain, persistent vomiting, vision changes, signs of kidney problems (decreased urination, swelling), or thoughts of self-harm, seek medical attention immediately. In an emergency, call 911.

Who may be a candidate for tirzepatide?

Tirzepatide may be considered for adults with:

• Obesity (BMI ≥30 kg/m²), or
• Overweight (BMI ≥27 kg/m²) with at least one weight-related medical condition, such as hypertension, dyslipidemia, or prediabetes

Eligibility is determined on an individual basis during a clinical evaluation. Your healthcare provider will review your medical history, current medications, lab results, and treatment goals to decide if tirzepatide is appropriate and safe for you.

Dosing and administration overview

Tirzepatide is administered as a once-weekly subcutaneous (under the skin) injection. Dosing typically starts low and is gradually increased (titrated) to help minimize gastrointestinal side effects and allow your body to adjust.

You can take tirzepatide with or without food, at any time of day, though consistency is helpful. Inject into the fatty tissue just beneath the skin in areas such as the abdomen, thigh, or upper arm. Rotate injection sites with each dose to reduce irritation and improve absorption.

Your clinician will provide specific dosing instructions tailored to your needs. Do not adjust your dose without medical guidance.

Comparing tirzepatide to other weight-loss medications

Several prescription medications are FDA-approved for weight management in the United States. Each works differently and carries its own benefits and risks.

Orlistat

Orlistat inhibits intestinal lipases, enzymes that break down dietary fat. This prevents roughly 30% of ingested fat from being absorbed, leading to modest weight loss—typically 6.5 to 7.5 pounds per year on average.

Common side effects include oily stools, increased bowel movements, gas, and difficulty absorbing fat-soluble vitamins (A, D, E, K). Orlistat is generally less effective than newer medications and is less commonly prescribed for obesity.

Naltrexone/bupropion (Contrave)

This combination targets reward pathways in the brain to reduce cravings and regulate eating behavior. Bupropion is an antidepressant and dopamine/norepinephrine reuptake inhibitor; naltrexone is an opioid receptor antagonist.

Common side effects include nausea, vomiting, constipation, headache, dizziness, and insomnia. It should not be used by people with uncontrolled hypertension, seizure history, eating disorders, or those undergoing withdrawal from drugs or alcohol. Average weight loss is around 11 pounds per year.

Phentermine/topiramate (Qsymia)

Phentermine suppresses appetite by increasing norepinephrine and dopamine; topiramate (an anti-seizure drug) may enhance satiety and reduce impulsive eating. Together, they can be more effective than either alone.

Common side effects include dry mouth, tingling, insomnia, mood changes, and rapid heartbeat. This medication is teratogenic (can harm a developing fetus) and must be avoided during pregnancy. Average weight loss ranges from 14.5 to 19 pounds per year.

Liraglutide (Saxenda)

Liraglutide is a GLP-1 receptor agonist, administered as a daily injection. It mimics the appetite-suppressing and blood-sugar-lowering effects of natural GLP-1.

Common side effects include nausea, diarrhea, constipation, vomiting, and injection site reactions. Like tirzepatide, it carries warnings for thyroid tumors (in rodents), pancreatitis, gallbladder disease, and kidney issues.

Semaglutide (Wegovy)

Semaglutide is a GLP-1 receptor agonist given as a once-weekly injection. It reduces appetite, slows gastric emptying, and lowers blood sugar. In clinical trials, semaglutide demonstrated substantial weight loss and improvements in metabolic markers such as blood pressure, cholesterol, and waist circumference.

Common side effects and contraindications are similar to tirzepatide, including GI symptoms, thyroid tumor warnings, and pancreatitis risk. Semaglutide should not be used during pregnancy or by individuals with a history of MTC or MEN2.

For a detailed comparison of leading GLP-1 and dual incretin medications, visit our GLP-1 Comparison Guide.

Tirzepatide (Zepbound, Mounjaro)

Tirzepatide is unique as the only dual GLP-1/GIP receptor agonist currently approved. In head-to-head and placebo-controlled trials, tirzepatide has shown some of the most robust weight-loss results among incretin-based therapies, with side effects and safety profiles similar to other GLP-1 medications.

Common side effects include nausea, diarrhea, vomiting, constipation, and fatigue. Serious risks mirror those of GLP-1 agonists: thyroid tumors (rodent data), pancreatitis, gallbladder disease, kidney injury, and mood changes.

Cost, insurance, and access

Insurance Note:
Coverage for GLP-1 and dual incretin medications varies widely and is often limited, particularly for weight loss indications. Many insurance plans impose strict criteria or do not cover these medications for obesity without comorbid diabetes. Alyn MD’s weight management programs are typically cash-pay. During your evaluation, your care team will review treatment options, pricing, and any potential insurance pathways.

Medication availability can fluctuate due to supply constraints. Alyn MD works to provide consistent access, but availability of specific brand-name or compounded formulations may vary.

How Alyn MD supports your weight-loss journey

Alyn MD offers a comprehensive, clinician-guided approach to weight management using evidence-based GLP-1 and dual incretin therapies like tirzepatide.

Here’s how it works:

1. Online evaluation: Complete a detailed health questionnaire and connect with a licensed clinician via telehealth.
2. Lab testing: If appropriate, your clinician orders labs through Labcorp or Quest Diagnostics. You visit a nearby collection site for in-person blood draws—no at-home kits.
3. Personalized treatment plan: Based on your evaluation and lab results, your clinician may prescribe tirzepatide or another therapy tailored to your goals and medical history.
4. Ongoing support: Regular follow-ups allow your care team to monitor progress, adjust dosing, manage side effects, and provide lifestyle guidance.

Alyn MD’s telehealth platform is available nationwide, making expert weight-loss care accessible no matter where you live.

Explore your options: Learn more about GLP-1 agonists

Real-world experiences: What users report

Patient experiences with tirzepatide vary. Based on reviews from platforms like Drugs.com and WebMD:

• Drugs.com: Tirzepatide received an average rating of 8.7 out of 10. Users reported significant, steady weight loss—often one to two pounds per week—with manageable side effects. Constipation was commonly mentioned. Some users who rated it lower cited side effects like rapid heartbeat, dizziness, or severe diarrhea.
• WebMD: Tirzepatide received an average rating of 3.8 out of 5 (based on limited reviews). Positive feedback highlighted effective weight loss, though challenges included medication shortages, diarrhea, body pain, and initial sensitivity or GI upset.

Individual responses to tirzepatide—and all weight-loss medications—vary widely. What works well for one person may cause intolerable side effects in another. It’s essential to discuss your goals, concerns, and medical history with a healthcare professional before starting treatment, and to maintain open communication throughout your care.

(4) FAQs

What makes tirzepatide different from other weight-loss medications?
Tirzepatide is the only approved dual incretin therapy, activating both GLP-1 and GIP receptors. This dual action may result in greater weight loss and broader metabolic benefits compared to single-receptor GLP-1 agonists like semaglutide or liraglutide. Clinical trial data suggest tirzepatide can support substantial weight reduction when combined with lifestyle changes, though individual results vary.

How much weight can I expect to lose on tirzepatide?
In clinical trials, participants on higher doses of tirzepatide achieved mean weight loss exceeding 20% of baseline body weight over 72 weeks. Real-world results vary based on starting weight, adherence to diet and exercise, dosing, and individual metabolism. Weight loss is not guaranteed, and maintaining results requires ongoing treatment and lifestyle support.

What are the most common side effects of tirzepatide?
The most frequent side effects are gastrointestinal: nausea, diarrhea, vomiting, constipation, indigestion, and abdominal discomfort. These tend to be most pronounced when starting the medication or increasing the dose and often improve over time. Eating smaller, more frequent meals and staying well-hydrated can help manage symptoms.

Who should not use tirzepatide?
Tirzepatide is contraindicated for individuals with a personal or family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN2). It should not be used by people with type 1 diabetes, those who are pregnant or planning to become pregnant, or anyone with a known hypersensitivity to the medication. People with a history of pancreatitis should discuss risks carefully with their clinician.

How is tirzepatide administered?
Tirzepatide is given as a once-weekly subcutaneous injection, which you administer yourself at home. It can be taken with or without food, at any time of day. Common injection sites include the abdomen, thigh, or upper arm. Rotate sites each week to reduce irritation and ensure consistent absorption. Your clinician or care team will provide detailed injection training.

Does insurance cover tirzepatide for weight loss?
Coverage is limited and varies by plan. Many insurance policies do not cover GLP-1 or dual incretin medications for weight loss unless strict medical criteria are met (e.g., diabetes diagnosis, documented comorbidities). Alyn MD’s weight management programs are typically cash-pay. Your care team can discuss pricing and any potential insurance pathways during your consultation.

Can I stop tirzepatide once I reach my goal weight?
Obesity is a chronic condition, and discontinuing medication often leads to weight regain. Long-term treatment, along with sustained lifestyle changes, is usually necessary to maintain weight loss. If you wish to stop tirzepatide, work closely with your clinician to develop a plan that includes dietary support, physical activity, and ongoing monitoring.

How does Alyn MD support patients using tirzepatide?
Alyn MD provides comprehensive telehealth care: initial evaluation, lab testing through Labcorp or Quest, personalized treatment plans, medication management, and regular follow-ups. Your clinician monitors progress, adjusts dosing as needed, manages side effects, and offers lifestyle coaching to help you achieve and maintain your weight-loss goals.