Tirzepatide, Actually Explained by an Endocrinologist

Editor’s note: This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional regarding any medical condition or treatment.

Everyone’s talking about weight loss medications, such as Ozempic and tirzepatide these days. Far fewer people can explain what they actually do.

Between conversations about “Ozempic face,” the wellness boom, and compounded versions of these medications being sold online for a fraction of the price, the medicine itself can get buried beneath the noise. That makes it easy to dismiss these drugs entirely—or pursue them without fully understanding what they’re intended to treat.

So, for a moment, we’re stepping away from the body-image debate and going straight to the medicine. Allure Philippines spoke with endocrinologist Assoc. Prof. Elaine C. Cunanan, MD, FPCP, FPCEDM, of the UST Faculty of Medicine and Surgery, to explain what tirzepatide actually is, who it’s for, how it works, and what you should know about its risks.

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What is tirzepatide, exactly?

Most people know tirzepatide by its brand names—Mounjaro, which is approved for Type 2 diabetes, and Zepbound, which is approved for chronic weight management—without necessarily knowing what makes it different from medications like Ozempic. According to Dr. Cunanan, one distinction comes down to the hormones it targets.

“While other medications like Ozempic work on just one hormone, tirzepatide targets GLP-1, the hormone that makes you feel full, and GIP, the hormone that helps the body process sugar and fat more effectively,” she explains.

That “dual action,” she says, “is why it’s shown to have stronger results in clinical trials than single-hormone drugs.”

Who is it actually for?

Tirzepatide isn’t intended for anyone who simply wants to lose weight—a distinction Dr. Cunanan emphasizes.

Its approved uses depend on the specific formulation and indication. Tirzepatide is used to help improve blood-sugar control in adults with Type 2 diabetes and, under its weight-management indication, for adults with obesity or certain adults who are overweight and have at least one weight-related health condition.

For chronic weight management, that generally means adults with a BMI of 30 or higher, or 27 or higher with a related condition such as high blood pressure, high cholesterol, cardiovascular disease, or obstructive sleep apnea.

Before prescribing it, doctors evaluate a patient’s medical history, BMI, health conditions, and potential contraindications. The medication is also intended to be used as part of a broader weight-management plan that includes, as Dr. Cunanan puts it, “a weight management program that includes calorie-controlled meals and physical activity.”

Does tirzepatide actually work?

The results aren’t simply anecdotal. Dr. Cunanan points to two major clinical-trial programs: SURPASS, which studied tirzepatide in people with Type 2 diabetes, and SURMOUNT, which studied its use for chronic weight management.

In Type 2 diabetes trials, tirzepatide produced substantial reductions in HbA1c, a measure of average blood sugar over time, and helped participants achieve improved glycemic control.

In weight-management trials, participants with obesity or overweight and qualifying weight-related health conditions experienced significant weight loss. But there’s an important caveat to the dramatic before-and-after stories that often circulate online: the medication isn’t necessarily a short-term intervention.

The benefits, Dr. Cunanan explains, are sustained “as long as they stayed on the medication.”

How does tirzepatide work in the body?

Dr. Cunanan says tirzepatide does two main things at the same time: “It tells your brain you’re full, so you’ll naturally eat less, and it helps the body manage insulin and blood sugar more efficiently after eating.”

“Because you feel less hungry, you eat smaller portions. When you eat less over time, your body uses its stored energy, eventually leading to weight loss,” she explains.

Tirzepatide also slows gastric emptying, meaning food moves through the stomach more slowly, which can contribute to feeling fuller for longer.

What are the benefits and side effects of tirzepatide?

Depending on why it is prescribed, tirzepatide can help improve blood-sugar control and support substantial weight loss. Clinical studies have also found improvements in some cardiometabolic measures associated with obesity, including blood pressure and lipid levels.

Like any prescription medication, however, it comes with potential side effects and risks.

Dr. Cunanan says the most common side effects are gastrointestinal, including nausea, diarrhea, constipation, vomiting, and abdominal discomfort. For many patients, these can improve as the body adjusts to the medication.

But common side effects aren’t the only consideration. Tirzepatide also carries warnings and precautions for potentially serious complications, which is one reason medical screening and ongoing supervision matter. Whether the medication is appropriate for a particular patient should be determined with a qualified healthcare professional.

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What about compounded versions of tirzepatide?

This is where understanding exactly what you’re buying becomes especially important.

Compounded medications are not the same as FDA-approved branded drugs. Unlike an approved medication, a compounded drug does not undergo the same premarket review for safety, effectiveness, and quality before reaching patients.

That distinction isn’t merely technical. Depending on the source and how a product is prepared, potential concerns can include incorrect dosing, contamination, inconsistent potency, or ingredients that differ from those in an approved formulation.

As Dr. Cunanan cautions, compounded products “are not interchangeable with the real brand-name products.”

For patients who are prescribed tirzepatide, Dr. Cunanan recommends using approved products obtained through legitimate medical and pharmacy channels. “These,” she explains, “have been tested in large studies to ensure their safety and effectiveness.”

Ultimately, Dr. Cunanan says that the safest and most reliable way to take tirzepatide is to “use the official, FDA-approved, brand-name versions prescribed by a doctor.” “These,” she explains, “have been tested in large studies to ensure their safety and effectiveness.” 

Before taking tirzepatide, talk to your doctor about whether you meet the medical criteria for treatment, your individual risks, and how the medication should be monitored. Be especially cautious about products sold through unregulated sources or at prices that seem suspiciously low.

Tirzepatide is not a diet hack, nor is it simply the drug behind a celebrity transformation or a viral before-and-after. It is a prescription medication with specific medical indications, meaningful benefits, and real risks.

And in a culture increasingly accustomed to discussing these drugs in terms of bodies—how quickly they shrink, how faces change, who is taking them—the distinction matters. Before tirzepatide is a beauty conversation, it is medicine.