Tirzepatide in the Philippines: evidence and status

What it is

Tirzepatide is a medicine used for type 2 diabetes and weight management. It is a dual GIP and GLP-1 receptor agonist and the active ingredient in Mounjaro and Zepbound.

• Mounjaro is approved in the US and the European Union.
• Zepbound is approved in the US. The US FDA approved it for chronic weight management on November 8, 2023.

These are US and EU approvals, not Philippine ones. In the Philippines, Mounjaro KwikPen and Mounjaro are listed as registered prescription drugs in the FDA Philippines Verification Portal (checked October 7, 2026). The Philippine package insert for Mounjaro KwikPen (linked from FDA Philippines Verification Portal record DR-XY49504) lists type 2 diabetes and weight management in adults.

Compounded tirzepatide also exists. A compounded preparation is not the same product as Mounjaro or Zepbound.

How it works

Tirzepatide acts like two hormones the body makes on its own, GIP and GLP-1. It binds to and activates both the GIP receptor and the GLP-1 receptor.

• Appetite. GLP-1 helps regulate appetite and how many calories you eat. Studies in animals and the lab suggest GIP may also play a part in regulating food intake. Both receptors are found in areas of the brain involved in appetite. The US Zepbound label says tirzepatide lowers calorie intake, likely by affecting appetite.
• Blood sugar. It increases insulin release and lowers glucagon, both depending on blood sugar levels (US Mounjaro label). In a 28-week clamp study in people with type 2 diabetes, it also increased insulin sensitivity (US Zepbound label).
• Long-lasting. It carries a fatty acid chain (a C20 fatty diacid) that lets it bind to albumin, a blood protein. This makes it last longer in the body.

What the research shows

Tirzepatide has been tested in large trials for weight, type 2 diabetes, sleep apnea and heart outcomes. This table summarizes the major ones.

These are trial results; they do not predict how any one person will respond. Compounded tirzepatide is not the same product as the Mounjaro and Zepbound described on this page.

SURMOUNT-1: weight in adults without diabetes

A phase 3, double-blind, randomized, placebo-controlled trial of weekly tirzepatide 5 mg, 10 mg or 15 mg.

The most common adverse events were gastrointestinal. Most were mild to moderate and happened mainly while the dose was being increased.

SURMOUNT-2: weight in adults with type 2 diabetes

A phase 3, double-blind, placebo-controlled trial in 938 adults with type 2 diabetes (HbA1c 7% to 10%). At week 72, 79% to 83% on tirzepatide had lost 5% or more of their weight, versus 32% on placebo. Fewer than 5% stopped because of gastrointestinal events.

SURMOUNT-3: after a lifestyle program

Adults who had already lost 5% or more through 12 weeks of intensive diet and exercise took tirzepatide (10 or 15 mg) or placebo. Over the next 72 weeks, 87.5% on tirzepatide lost a further 5% or more, versus 16.5% on placebo.

SURMOUNT-OSA: sleep apnea

Two double-blind trials in adults with obesity and moderate to severe obstructive sleep apnea. One group was not using a breathing machine (PAP) and one was. At the start, people had about 50 breathing events per hour (AHI).

SURPASS-CVOT: heart outcomes in type 2 diabetes

This trial compared tirzepatide with another diabetes medicine, dulaglutide, rather than with placebo. Heart death, heart attack or stroke happened in 12.2% on tirzepatide and 13.1% on dulaglutide. Tirzepatide met the noninferiority test (P = 0.003). The test for fewer events than dulaglutide was not met (P = 0.09).

SUMMIT: heart failure

In people with heart failure with preserved ejection fraction and obesity, the combined outcome of heart death or a worsening heart failure event happened in 9.9% on tirzepatide and 15.3% on placebo. The difference came from worsening heart failure events (8.0% vs 14.2%). Heart death was not reduced: 2.2% on tirzepatide vs 1.4% on placebo. The August 2026 US Zepbound label does not list a heart failure indication.

SURMOUNT-1 three-year analysis: prediabetes

People with obesity and prediabetes stayed on treatment for 176 weeks, about 3 years. Weight change was -12.3%, -18.7% and -19.7% with 5, 10 and 15 mg, versus -1.3% with placebo. Type 2 diabetes was diagnosed in 1.3% on tirzepatide and 13.3% on placebo.

SURPASS-2 and SURMOUNT-5 are covered under "How it compares with semaglutide" below.

How fast it works and what to expect over time

In one trial analysis, most people had lost 5% or more of their weight within 12 weeks. In this SURMOUNT-1 analysis of 1,545 people on tirzepatide who took at least 75% of their doses, 82% had lost 5% or more of their weight by week 12. These are trial results; they do not predict how any one person will respond.

Some people respond later. Of the 18% who had not reached 5% by week 12, 70% reached it by week 24 and 90% by week 72. Their average time to reach 5% was 24.8 weeks.

The US Zepbound label measured weight loss after 72 weeks of treatment, with at least 52 weeks at the maintenance dose. It shows the curve from week 0 to 72 only as a figure and does not state a week at which weight loss levels off.

What happens if you stop

In SURMOUNT-4, weight came back after stopping. The trial tested this directly.

In that trial, the 670 adults who completed 36 weeks of tirzepatide had lost a mean of 20.9%. They were then randomly assigned to keep taking it or switch to placebo for 52 more weeks.

The authors concluded: "withdrawing tirzepatide led to substantial regain of lost weight, whereas continued treatment maintained and augmented initial weight reduction."

In the SURMOUNT-1 prediabetes group, people were followed for 17 weeks after 176 weeks of treatment. By then, 2.4% of those who had taken tirzepatide had type 2 diabetes, versus 13.7% of those who had taken placebo. During treatment, the figures were 1.3% and 13.3%.

For diabetes vs for weight (Mounjaro vs Zepbound)

Mounjaro and Zepbound contain the same medicine, tirzepatide, but are approved for different uses depending on the regulator.

At US approval, Zepbound was for adults with a BMI of 30 kg/m2 or more, or 27 kg/m2 or more with at least one weight-related condition. The US FDA says Zepbound should not be used together with Mounjaro or a GLP-1 receptor agonist.

In the Philippines, Mounjaro KwikPen and Mounjaro are listed as registered in the FDA Philippines Verification Portal (checked October 7, 2026). No record was found for Zepbound in a portal search on the same date. The Philippine package insert for Mounjaro KwikPen, linked from the portal for DR-XY49504 (the same file is linked for DR-XY49505), lists type 2 diabetes and weight management in adults, as shown in the table. It lists no indication for children, heart risk or sleep apnea.

How it is taken and stored

On the US Mounjaro and Zepbound labels: tirzepatide is a once-weekly injection under the skin. The labels say to give it once weekly at any time of day, with or without meals. It is injected in the abdomen or thigh, or another person can inject it in the back of the upper arm. Injection sites are rotated with each dose. Zepbound is used together with a reduced-calorie diet and more physical activity. These are not instructions for compounded tirzepatide. Your doctor sets your dose and explains how to take it.

Forms. On the US labels, tirzepatide comes as a clear, colorless to slightly yellow solution in single-dose pens, single-dose vials, multi-dose vials or single-patient-use KwikPens. The multi-dose vial and the KwikPen each hold 4 doses. The Philippine package insert for Mounjaro KwikPen says: "Each pre-filled KwikPen contains 2.4 ml of solution for injection (4 doses of 0.6 ml)." The US labels say to check the solution before use and not to use it if you see particles or a change in color.

Do not share pens. The Mounjaro Medication Guide warns: "Do not share your MOUNJARO KwikPen or needles with other people, even if the needle has been changed. You may give other people a serious infection, or get a serious infection from them."

Storage on the Philippine package insert and the US labels:

The Zepbound label says that once a multi-dose vial or KwikPen is opened, it can be kept in its carton in the refrigerator or at room temperature (up to 30°C). Throw it away after 30 days at room temperature, 30 days after first use, or after 4 weekly doses, even if medicine is left.

For all forms, both US labels say: do not freeze, and do not use if it has been frozen. Protect from heat and light, and keep it in the original carton.

The labels differ on an opened KwikPen: the Philippine package insert says to store it unrefrigerated below 30°C, while the US Zepbound label allows the refrigerator or room temperature up to 30°C. The Philippine package insert applies to products registered in the Philippines.

The dose schedule on the US labels

The US labels start tirzepatide at a low dose and raise it step by step. Both labels say to follow the schedule to reduce the risk of gastrointestinal side effects. This is the label schedule, not personal advice. Your doctor sets your dose.

These schedules are for the branded medicines Mounjaro and Zepbound. They are not schedules for compounded tirzepatide.

The Zepbound label gives a maintenance dose of 5 mg, 10 mg or 15 mg once weekly for weight reduction and long-term maintenance, and 10 mg or 15 mg once weekly for sleep apnea. It says the 2.5 mg dose is for starting treatment and is not approved as a maintenance dose. It also says to consider treatment response and tolerability when choosing the maintenance dose, and to consider a lower maintenance dose if a person does not tolerate it.

Side effects and how common they are

The most common side effects affect the stomach and gut. In the US Zepbound label's weight trials, gastrointestinal side effects happened in 56% of people on each tirzepatide dose, versus 30% on placebo.

The Zepbound label says: "The majority of nausea, vomiting, and/or diarrhea events occurred during dose escalation and decreased over time."

Other common side effects (reported in 5% or more of people):

• Zepbound label: nausea, diarrhea, vomiting, constipation, abdominal pain, indigestion, injection site reactions, fatigue, allergic (hypersensitivity) reactions, burping, hair loss and acid reflux (gastroesophageal reflux disease).
• Mounjaro label: nausea, diarrhea, decreased appetite, vomiting, constipation, indigestion and abdominal pain.

How many people stopped. In SURMOUNT-1, side effects led 4.3%, 7.1% and 6.2% of people on 5, 10 and 15 mg to stop, versus 2.6% on placebo. In SUMMIT, 6.3% on tirzepatide stopped because of side effects, mainly gastrointestinal, versus 1.4% on placebo. In SURPASS-CVOT, side effects were broadly similar to dulaglutide, with more gastrointestinal events on tirzepatide.

Muscle and fat. In a SURMOUNT-1 body scan (DXA) substudy of 160 people, tirzepatide reduced body weight by 21.3%, fat mass by 33.9% and lean mass by 10.9% at week 72. With placebo the figures were 5.3%, 8.2% and 2.6%. In both groups, about 75% of the weight lost was fat and 25% was lean mass. The US Zepbound label says tirzepatide "lowers body weight with greater fat mass loss than lean mass loss."

Serious warnings and who should not use it

Boxed warning (US Zepbound label). In rats, tirzepatide causes thyroid C-cell tumors, and the risk rises with dose and length of treatment, at exposures relevant to people. It is unknown whether it causes these tumors, including medullary thyroid carcinoma (MTC), in humans.

Who must not use it. The US Zepbound label says tirzepatide must not be used by people with a personal or family history of MTC or with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). It is not recommended for people with severe gastroparesis.

Serious risks listed on the US Zepbound label (low blood sugar is from the US Mounjaro label):

• Gallbladder: tirzepatide and GLP-1 receptor agonists are linked to more cases of acute gallbladder disease.
• Pancreatitis: acute pancreatitis, including fatal and non-fatal hemorrhagic or necrotizing pancreatitis, has been seen with GLP-1 receptor agonists or tirzepatide.
• Low blood sugar (US Mounjaro label): taking tirzepatide with insulin or an insulin secretagogue, such as a sulfonylurea, may raise the risk of hypoglycemia, including severe hypoglycemia.
• Kidneys: dehydration from side effects can lead to acute kidney injury. The US Zepbound label advises monitoring kidney function in these people, especially when starting treatment.
• Allergic reactions: serious reactions, such as anaphylaxis and angioedema, have been reported after marketing.
• Eyes: in people with type 2 diabetes, temporary worsening of diabetic retinopathy has been reported with rapid improvement in blood sugar control.
• Surgery and sedation: rare cases of pulmonary aspiration have been reported in people on GLP-1 receptor agonists having procedures under general anesthesia or deep sedation.

Birth control. Tirzepatide may make birth control pills less effective. The US Zepbound label advises switching to a non-oral method, or adding a barrier method, for 4 weeks after starting and for 4 weeks after each dose increase.

Pregnancy. Weight loss offers no benefit during pregnancy and may harm the baby. The US Zepbound label advises stopping tirzepatide when a pregnancy is recognized.

In SURMOUNT-2, 7% of participants reported serious adverse events. Two deaths in the 10 mg group were judged by the investigator as not related to the study treatment.

Branded, compounded and unregistered tirzepatide

Not every product sold as "tirzepatide" is the same. There are three kinds.

Branded. Mounjaro and Zepbound are the brand-name medicines approved in the US, and Mounjaro also in the EU. Mounjaro KwikPen and Mounjaro are listed as registered in the FDA Philippines Verification Portal (checked October 7, 2026). The label facts on this page come from the US Mounjaro and Zepbound labels.

Compounded. Compounded tirzepatide is a compounded preparation. It is not the same product as Mounjaro or Zepbound.

The US FDA has made these statements about compounded tirzepatide. They apply to the US legal framework, not the Philippines:

• October 2, 2024: "Compounded drugs are not approved by FDA," and "When a drug shortage is resolved, FDA generally considers the drug to be commercially available."
• December 19, 2024: "FDA has issued a new decision determining the tirzepatide injection shortage is resolved."
• March 10, 2025: for state-licensed pharmacies and physicians compounding under section 503A, "the period of enforcement discretion described below has ended." The period for 503B outsourcing facilities ran until March 19, 2025.
• April 1, 2026: "Tirzepatide and semaglutide do not currently appear on the 503B bulks list or on FDA's drug shortage list."
• Page current as of October 1, 2026: the US FDA says unapproved versions do not go through FDA review before they are marketed, and that compounded drugs "should only be used in patients whose medical needs cannot be met by an FDA-approved drug." As of May 31, 2026, it had received "more than 730 reports of adverse events associated with compounded tirzepatide", and says such events are likely underreported.

The same US FDA page says it has received adverse event reports that may be related to compounded semaglutide or tirzepatide prescribed in doses beyond the FDA-approved label.

Unregistered and "research" products. The US FDA says it is aware of fraudulent compounded tirzepatide with labels naming pharmacies that do not exist or did not make the product. It has warned companies selling tirzepatide falsely labeled "for research purposes" or "not for human consumption".

In the Philippines, FDA Philippines has warned the public against unregistered tirzepatide products that have no Certificate of Product Registration (see the advisories below). No FDA Philippines statement specifically about compounded tirzepatide was found.

Zuellig Pharma, the Philippine distributor of Mounjaro, has warned that illegally compounded tirzepatide poses significant health risks. It cited improper dosing that may lead to severe adverse effects, and possible impurities and contamination because of a lack of regulatory oversight (BusinessWorld, April 2026).

How to get tirzepatide legally in the Philippines

The FDA Philippines Verification Portal lists the branded tirzepatide products Mounjaro KwikPen and Mounjaro as prescription drugs (checked October 7, 2026). The legal route has three parts:

1. A prescription. Under the Philippine Pharmacy Act (RA 10918, Sections 30 and 33), prescription medicines may be dispensed only with a valid prescription from a physician, dentist or veterinarian.
2. A licensed pharmacist. They may be dispensed only by a registered and licensed pharmacist.
3. A licensed outlet. Medicines may be sold to the public only through a retail drug outlet licensed by FDA Philippines.

The portal lists Zuellig Pharma Corporation as importer and distributor of Mounjaro KwikPen and Mounjaro. You can check a product's status on the FDA Philippines verification portal.

FDA Philippines has warned the public not to buy or use unregistered tirzepatide products (see the advisories below).

How it compares with semaglutide

Tirzepatide and semaglutide act on different targets. Tirzepatide activates the GIP and GLP-1 receptors. Semaglutide acts like the hormone GLP-1 (EMA, Wegovy). Tirzepatide is a once-weekly injection. On the US labels, Wegovy and Ozempic injections are also given once weekly, and Wegovy also comes as a once-daily tablet.

Two head-to-head trials are summarized here. Both were open-label, meaning participants knew which medicine they took.

These are results from two trials with set populations, doses and durations. They do not predict how any one person will respond, and which medicine fits a person is a decision for their doctor.

In the Philippines, Mounjaro KwikPen and Mounjaro (tirzepatide) and Ozempic, Wegovy and Rybelsus (semaglutide) are listed as registered prescription drugs in the FDA Philippines Verification Portal (checked October 7, 2026). Rybelsus is registered as tablets; the others are solutions for injection.

More detail: semaglutide vs tirzepatide and semaglutide.

Legal status in the Philippines

Mounjaro KwikPen (0.6 mL) and Mounjaro (0.5 mL), both tirzepatide solution for subcutaneous injection, are listed as registered in the FDA Philippines Verification Portal (checked October 7, 2026). The portal shows 12 registrations, all valid on that date, with Zuellig Pharma Corporation as importer and distributor. No record was found for Zepbound in a portal search on the same date.

All 12 Mounjaro registrations are classified as prescription drugs. Under RA 10918, these may be dispensed only by a licensed pharmacist with a valid prescription, through a retail drug outlet licensed by the FDA.

The approved uses on this page come from the US FDA and the European Union. The uses approved in the Philippines could not be confirmed.

FDA Philippines advisories

FDA Philippines has issued public health warnings about unregistered tirzepatide products.

• FDA Advisory No. 2026-0814 (dated July 30, 2026). FDA post-marketing surveillance found that an unregistered tirzepatide product has no Certificate of Product Registration. The public was warned not to buy or use it, and establishments were warned not to distribute it until it is authorized.
• FDA Advisory No. 2026-1020 (dated September 1, 2026). As reported by SunStar Philippines in September 2026, FDA Philippines warned the public against buying or using an unregistered tirzepatide product. The agency said it "has not undergone the required registration process, and has not been issued with the appropriate authorization in the form of Certificate of Product Registration (CPR)", and that use "may expose them to potential health risks, including possible injury or harm."

Other advisories naming tirzepatide products may exist.