Still not losing weight on semaglutide at week 6?

Why is week 6 too early to judge whether semaglutide is working?

The licensed dosing pathway for Wegovy starts at 0.25 mg weekly, stepping up roughly every four weeks. By week 6 you've likely just moved to 0.5 mg, or you're still at the starting dose if your prescriber asked you to stay there a little longer to manage nausea. Neither of those doses is therapeutic in the sense of driving substantial fat loss. Their job is to train your body to tolerate the medicine before you reach the doses where appetite suppression becomes genuinely powerful.

The STEP 1 trial (published in the New England Journal of Medicine) ran for 68 weeks, and the average 15% body-weight reduction reported at 2.4 mg was built over that entire period. Weight loss in that trial wasn't front-loaded; it accumulated as doses increased and the medicine's full effect on appetite took hold. Expecting equivalent progress at week 6 is a bit like checking the oven ten minutes into a ninety-minute roast.

Our guide on how long Wegovy takes to work covers the expected timeline in more detail, and if you're wondering how long you're likely to be on Wegovy altogether, that's worth reading alongside it. The short version: if you're frustrated at week 6, you're in good company, and almost certainly not at a dose where the medicine has shown its hand yet.

Could something specific be stopping the scales from moving?

There's a difference between semaglutide not working and semaglutide working but being outpaced by something else. A few things worth considering honestly.

Calorie compensation is the quietest saboteur. Semaglutide reduces appetite, but it doesn't eliminate food choices. Some people find the reduced nausea at lower doses means they eat more comfortably than expected, especially if high-calorie foods are small in volume. Alcohol is a separate issue: it's calorically dense, blunts satiety signals and is worth reviewing with your prescriber if it's a regular feature.

Water retention also distorts the picture more than people expect. Starting any new medicine, changing how much you eat, or even a saltier week can add 1–2 kg of fluid that sits on the scales while actual fat loss is happening underneath it. Menstrual cycle phase, constipation (a common early side effect of GLP-1 medicines, noted on the NHS semaglutide page) and reduced physical activity can all do the same.

Some people also find the very early weeks triggering more nausea than hunger suppression, which (counterintuitively) can lead to eating quickly or choosing less nutritious foods just to manage the discomfort. If that sounds familiar, it's worth flagging to your prescriber rather than pushing through quietly. There are practical strategies that help, and your dose schedule can be discussed.

If you were already not seeing movement in the first couple of weeks, our week 2 page covers that earlier window specifically.

What should you actually do if the scales aren't moving at week 6?

First: don't stop the medicine based on a six-week read. The broader guide on no weight loss on semaglutide sets out when that decision genuinely needs making (NICE guidance refers to assessing response after six months at maintenance dose, not six weeks at a starter dose). Stopping early means you'll never know what the medicine could have done once you reached a meaningful dose.

What does make sense at week 6: keep a straightforward food and drink log for two weeks and share it with your clinical team. Not to be judged, but because patterns that feel unremarkable to you often reveal something useful to a prescriber. It's also worth noting whether the medicine is reducing your appetite at all (even partially) because that tells you the mechanism is engaging, even if the scales haven't caught up.

Check whether any other medicines you take could be interacting. Some common drugs affect how quickly your stomach empties, which overlaps with semaglutide's mechanism. Your prescriber is the right person to review that list, not a forum. If you're on any form of hormonal contraception, the Wegovy overview covers the relevant guidance on contraception during treatment, which is worth being aware of.

And practically: if you ordered your first pen around a bank holiday or payday, there's sometimes a gap between doses that people don't account for. Even a few days' delay in a six-week window can affect what you've actually received. It's worth checking your records.

When does a prescriber consider changing the plan?

A prescriber's job at this stage is to distinguish between "not working yet" and "not working for this person at any dose". Those are very different situations, and six weeks almost never resolves the question, unless there are side effects serious enough to outweigh the benefit of continuing.

For people wondering whether Wegovy isn't working at all, the clinical marker NICE references is less than 5% weight loss after six months at the highest tolerated dose. That's a long way from week 6 on a starter dose. If you're being reviewed privately, a good prescriber will also ask about sleep, stress and thyroid function, all of which affect weight independently of medication.

Dose increases can only happen safely with clinical oversight. At nume, every repeat order goes through a clinician review before anything is dispensed, that review is where changes to your schedule would be discussed. If you have specific concerns now, our team is reachable seven days a week.

If you're still weighing up whether to start or continue, the cost question often comes up alongside the clinical one. Our treatment page sets out what's included in a single transparent price. Ready to talk through your options? Check your eligibility with a free consultation.