Injectable dual-action
Tirzepatide Injection
Weekly, injectable dual-action treatment for weight loss.
Tirzepatide works on two of your body's appetite and blood sugar systems rather than one. In studies, that dual action produced greater average weight loss than treatments working on a single system.
- Format
- Subcutaneous injection
- Cadence
- Once weekly
- Dose range
- 2.5 mg up to 15 mg
- From
- $299 per month
How it works
Two systems, not one
Tirzepatide acts on two different gut hormone pathways. The first reduces hunger and slows stomach emptying. Adding the second appears to improve both appetite control and how your body handles fat and sugar.
Larger average results
In its studies, people on the highest dose lost around 20% of their body weight over about 17 months, against roughly 15% for semaglutide in its own studies. Those were separate trials, not a direct head to head.
The same trade-off
Side effects are mostly digestive and follow a familiar pattern. Worst just after a dose increase, better with time.
What to expect
- Weeks 1 to 4
Starting dose, to let your body adjust. Not yet a treatment dose.
- Weeks 5 to 20
Dose steps up roughly every 4 weeks if you are tolerating it. Most people find the dose that works for them somewhere in this range.
- Month 6 onward
Settled on a maintenance dose, or lower if that is where results and side effects balance for you.
Dosing & titration
| Weeks 1 to 4 | 2.5 mg weekly |
|---|---|
| Weeks 5 to 8 | 5 mg weekly |
| Weeks 9 to 12 | 7.5 mg weekly |
| Weeks 13 to 16 | 10 mg weekly |
| Weeks 17 to 20 | 12.5 mg weekly |
| Week 21 onward | Up to 15 mg weekly |
This is a guide, not your prescription. Plenty of people stop increasing well before the top dose. Higher is not automatically better.
Is it right for you?
Often a good fit
- Adults with a BMI of 30 or above, or 27 and above with a weight-related condition
- People who have stalled on a single-action GLP-1
- People who want the strongest average results and can manage the dose increases
Not a fit
- Anyone with a personal or family history of medullary thyroid cancer
- Pregnancy, breastfeeding, or trying to conceive
- Anyone who has had pancreatitis, which needs careful review first
- Anyone already taking another medicine in this class
Safety information
The reference versions of these medicines carry the FDA's strongest form of warning. In animal testing they caused thyroid tumours. It is not known whether they do the same in people, but anyone with a personal or family history of a particular thyroid cancer should not take them.
Do not take this medicine if you have
- A personal or family history of medullary thyroid cancer
- A rare inherited condition called Multiple Endocrine Neoplasia type 2
- A previous serious allergic reaction to semaglutide or tirzepatide
- Pregnancy, trying to conceive, or breastfeeding
Common side effects
- Nausea
- The most common one, usually strongest in the days after a dose increase.
- Vomiting and diarrhoea
- Normally early and temporary. Tell your doctor if it carries on.
- Constipation
- Fluids, fibre and movement help. Your doctor can advise.
- Stomach pain, reflux, burping
- Smaller, slower, lower-fat meals usually settle this.
- Tiredness and headache
- Often a sign you are not eating or drinking enough.
Serious risks, seek care if these occur
- Inflammation of the pancreas
- Severe stomach pain that will not go away, with or without vomiting. Stop taking it and get medical help.
- Gallbladder problems
- Losing weight quickly raises the risk of gallstones. Pain under your right ribs, fever or yellowing skin needs urgent attention.
- Low blood sugar
- The risk rises sharply if you also take insulin or certain diabetes tablets. Those doses need reviewing before you start.
- Kidney problems
- Usually caused by dehydration from vomiting or diarrhoea. Keep your fluids up.
- Eye changes if you have diabetes
- If you already have diabetic eye disease, improving your blood sugar quickly can make it worse for a time. Tell your doctor.
- Slowed stomach emptying
- This can become a problem in its own right, and it matters before surgery. Tell any surgeon or anaesthetist that you are taking this medicine.
Interactions
Because these medicines slow how quickly your stomach empties, they can change how fast other tablets are absorbed. Give your doctor your full medication list, including insulin, diabetes tablets, thyroid medication and the contraceptive pill.
This summary is not complete. Your physician will review your full history, and you should read the information supplied with your medication.
