The usual dose of tirzepatide — and how the schedule actually works

Step 1: the opening four weeks at 2.5 mg

Every tirzepatide journey begins at 2.5 mg regardless of a person's weight, BMI, or medical history. The reason is straightforward: the most common side effects (nausea, loose stools, indigestion) are most pronounced when the gut first encounters the medicine. Starting low keeps those effects manageable while your digestive system adapts to slower gastric emptying.

During these first four weeks you are not yet at a dose expected to produce meaningful weight loss. That framing matters. Some people feel discouraged when the scales barely move in month one; the 2.5 mg pen is doing a different job. Think of it as preparation rather than treatment proper. You inject once a week, typically into your abdomen, thigh, or upper arm, rotating the site each time.

Practical detail worth knowing: the pen that arrives (in a plain, unbranded box with DPD tracking on your phone) contains four weekly doses pre-set at the same strength. You do not adjust anything manually. Each dose is dialled and delivered by the pen itself.

If GI side effects are particularly rough at 2.5 mg, tell your prescriber before moving up. Staying at the lower dose for an additional four weeks is a recognised option in the licensed guidance. Rushing the schedule tends to make the next step harder, not easier. More on what to expect at the opening dose is covered on our 2.5 mg tirzepatide page.

Step 2: moving through 5 mg, 7.5 mg, and beyond

After the first four weeks, a prescriber reviews your progress and, if you are tolerating treatment well, moves you to 5 mg, the point where most people first notice the appetite-suppressive effect becoming tangible. Meals feel satisfying sooner, the pull to snack between them weakens. Weight loss typically begins at this stage, though the rate varies considerably between individuals.

The schedule then continues in 2.5 mg increments roughly every four weeks: 7.5 mg, 10 mg, 12.5 mg. At each step, the prescriber is looking at two things: how well you are tolerating the current dose and whether you are making meaningful progress. Neither question has a single right answer, which is why clinical review before each increase matters. An automated system cannot make that call.

By the time you reach 10 mg or 12.5 mg you are in the range where the SURMOUNT-1 trial (involving over 2,500 adults) recorded substantial average weight reductions. The trial data, published in the New England Journal of Medicine, showed around 20–21% average body-weight reduction at the 15 mg dose over 72 weeks, with lower but still clinically meaningful results at intermediate doses. NICE cited this evidence in its December 2024 recommendation of tirzepatide for weight management in England. You can see more detail on how the different dose levels compare on our tirzepatide doses overview.

Dose increases are never automatic. If you feel you are doing well at 10 mg and have no desire to go higher, that conversation belongs with your prescriber, who will weigh the clinical picture.

Step 3: reaching a maintenance dose, and what that means

The 15 mg dose is the maximum licensed strength in the UK and, in the SURMOUNT trial programme, produced the greatest average weight reduction. Whether you actually need to reach it is a different matter. Some people achieve the weight loss their prescriber considers clinically appropriate at 5 mg or 7.5 mg and stay there. Others plateau at 10 mg and a dose increase becomes the sensible next step. Maintenance means the dose that continues to support your health goals without causing side effects that outweigh the benefit.

There is no fixed timeline for reaching maintenance. If GI effects slow the titration, the schedule stretches. If a dose is well tolerated and progress is steady, the review may confirm continuing at the same level. What the licensed guidance does specify is that if you have not lost at least 5% of your starting body weight after six months at the highest dose you can tolerate, your prescriber should review whether continuing makes sense. NICE referenced this threshold in its appraisal published at NICE TA1026.

One question our prescribers hear regularly is whether reaching a higher dose means staying there forever. It does not. Some people reduce to a lower maintenance dose; others come off treatment altogether after sustained weight loss. Those decisions are made individually, based on your progress and overall health. If you are weighing up how the titration fits your situation before starting, our tirzepatide dosing page covers the clinical decision points in more depth, and you can explore treatment options on our weight-loss treatments page.

What the prescriber considers at each review

Every dose increase at nume is preceded by a clinical review, a real prescriber reads your update, not software. That review looks at how the current dose has affected your weight, appetite and side-effect burden, and whether anything in your health picture has changed since the last check. Evidence of your current weight is required before increases are confirmed, which is also why the process involves live weight verification at the outset.

Side effects tend to be most noticeable in the first week or two after a dose change, then settle. Nausea, looser stools, and reduced appetite for certain foods are the most common reports, particularly after moving up the schedule. The side-effect profile of Mounjaro, the branded name for tirzepatide, is detailed on the NHS medicines page linked above. Severe or persistent stomach pain that radiates to the back is not a tolerable GI effect, it warrants prompt medical attention.

People wondering whether the cost changes as doses go up will find a straightforward breakdown on our Mounjaro price comparison page. The broader question of who meets the eligibility criteria for tirzepatide (BMI thresholds, qualifying conditions, NHS versus private routes) is separate from the dose schedule itself, though it shapes which strength you start on and how your prescriber approaches titration. Our clinical team profile is on the clinical team page if you want to understand the oversight behind every review. Check your eligibility by starting a free consultation whenever you are ready.