Starting Wegovy tablets is a big step, and it's natural to want to know what's coming. Your first week won't bring dramatic weight loss, it's really an adjustment period, where your body gets used to a new medication and you start building the habits that will carry you through treatment.
Here's what's actually happening in week one, what you might feel, and how to make the week as smooth as possible.
Understanding how Wegovy tablets work in your first week
Wegovy tablets contain semaglutide, a medication that mimics a natural hormone involved in regulating hunger and appetite. In your first week, you'll be on the lowest dose in the titration schedule. This is your starting point, not your target dose.
Think of week one as a foundation-laying phase rather than a results phase. You're not meant to notice major changes yet. Instead, this week is about:
- Establishing a consistent daily routine with your medication
- Giving your body a chance to begin adjusting to semaglutide
- Building a tolerance baseline before the dose increases
Knowing this in advance can help you set realistic expectations, so you're not disappointed if the scale hasn't moved much, and not alarmed if you feel a little off as your body adapts.
How semaglutide begins affecting your body
Semaglutide works by signalling to your brain that you're full, slowing digestion, and reducing food cravings. In week one, it starts interacting with receptors in your gut and brain, which is exactly why some of the earliest side effects appear this early on.
You may notice:
- Appetite suppression beginning subtly within the first few days (though this varies a lot from person to person)
- Feeling full after smaller portions than you're used to
- Your eating habits shifting naturally as hunger signals become quieter
None of this happens on a fixed timetable. Some people notice changes almost immediately; others barely notice anything until later weeks.
The starting dose and what it means for week one
Your first week follows a deliberately low starting dose, as part of the wider dose titration process. This isn't a smaller version of the "real" treatment, it's an essential part of it.
Starting low is intentional. It allows your body to adjust gradually and helps reduce the severity of side effects that can come with jumping straight to a higher dose. Because of this:
- You won't be on the full therapeutic dose in week one
- Effects may feel mild or subtle compared to what you might have read about
- The dosing schedule increases slowly over several weeks, making week one the gentlest phase
Following your prescribed schedule exactly during this first week matters for how well you tolerate the medication long-term, so it's worth resisting any temptation to go faster than advised.
What you will likely feel and experience in the first week
Common physical side effects to expect
Nausea is the most frequently reported side effect in week one, and it's usually mild at this starting dose. Alongside this, you might experience:
- Stomach upset such as bloating, indigestion, or general abdominal discomfort as your digestive system adjusts
- Constipation or diarrhoea, as semaglutide slows or disrupts normal digestive movement
- Vomiting, though this is less common in week one at the low starting dose, particularly after large meals
- Headache, often linked to changes in eating habits and reduced calorie intake
- Dizziness, especially if you're eating significantly less and not keeping hydration up
- Fatigue or low energy, as your body adapts to appetite changes
Appetite and hunger changes you may notice
Many people notice a reduction in appetite within the first few days. Cravings (particularly for high-calorie or processed foods) may start to feel less intense, and you might feel satisfied after portions far smaller than you're used to. Some people even find themselves indifferent to meals they previously enjoyed.
This can feel unfamiliar, even a little unsettling, but it's a normal part of adjusting. And if you're not noticing much appetite change yet, that's normal too; for many people, these effects build gradually over the first few weeks rather than appearing all at once.
Energy levels, mood, and sleep quality
Fatigue is common in week one as your body adjusts to reduced calorie intake. Some people also notice:
- Mood changes, i.e. feeling slightly low, irritable, or emotionally flat
- Disrupted sleep or unusual tiredness
- Energy dips linked to eating less before your nutrition has caught up with smaller portions
These effects are typically temporary and tend to ease as your body adapts beyond the first week.
Hydration and dehydration risks
Reduced appetite can mean forgetting to drink enough fluids, and if you're also experiencing diarrhoea or vomiting, fluid loss can accelerate quickly. Dehydration can bring on headaches, dizziness, and fatigue, which overlap heavily with common Wegovy side effects, making it easy to mistake one for the other.
Drinking water consistently throughout the day is especially important in week one. Staying hydrated supports digestion and can genuinely help ease nausea and stomach discomfort.
How to manage your first week successfully
Practical tips for handling side effects
- Eat smaller, more frequent meals rather than large portions to reduce nausea and stomach upset
- Avoid rich, fatty, or heavily spiced foods, which can worsen digestive discomfort and bloating
- Take your tablet at the same time each day to build a routine and reduce unpredictability
- If nausea strikes, bland foods like crackers, toast, or plain rice can help
- Rest when fatigue hits, and hold off on intense physical activity this week
- Keep a simple food and symptom diary to help spot patterns and triggers
Adjusting your eating habits from day one
Week one is a good time to start practising mindful eating, paying attention to the fullness cues that Wegovy tablets begin to enhance. A few habits worth building early:
- Reduce portion sizes voluntarily, working with the medication's appetite-suppressing effect rather than against it
- Prioritise protein and fibre-rich foods to help maintain energy while eating less overall
- Avoid eating past fullness, even if your portions feel unusually small
- Keep healthy, low-calorie options on hand for the cravings that may still show up
When to seek guidance and what to watch for
Most side effects in week one are mild and expected. Nausea, headache, and fatigue don't usually mean you need to stop the medication. But some symptoms need prompt attention:
- Severe or persistent vomiting, diarrhoea, or stomach pain should be reported to your healthcare provider
- Signs of significant dehydration, such as dark urine, extreme dizziness, or confusion, need urgent medical attention
- Mood changes that feel severe, or any symptoms of depression, should be discussed with your doctor
It's worth reading the patient information leaflet that comes with your Wegovy tablets so you know which symptoms are expected and which warrant support. Your first week is just the start of a longer journey. Reaching out early if something doesn't feel right builds a strong foundation for the weeks ahead.
References
- Novo Nordisk / U.S. FDA. Highlights of Prescribing Information: Wegovy (semaglutide) tablets and injection. Available at: novo-pi.com/wegovy.pdf
- U.S. Food and Drug Administration. Wegovy Prescribing Information (Label). Available at: accessdata.fda.gov
- Novo Nordisk. Wegovy® Safety Information. Available at: wegovy.co.uk/safety-information.html
- electronic Medicines Compendium (emc). Wegovy Patient Information Leaflet. Available at: medicines.org.uk/emc
- U.S. National Library of Medicine, DailyMed. WEGOVY – semaglutide injection, solution; WEGOVY – semaglutide tablet. Available at: dailymed.nlm.nih.gov
- GoodRx Health. 20 Ozempic and Wegovy Side Effects You Should Know About. Available at: goodrx.com
- MedExpress UK. Wegovy Pill: What It Is, How It Works and When You Can Get It. Available at: medexpress.co.uk
- Asda Online Doctor. Wegovy Pill Side Effects & How to Manage Them. Available at: onlinedoctor.asda.com
- Simple Online Pharmacy. Wegovy Pill and Nausea: How Long It Lasts and How to Manage It. Available at: simpleonlinepharmacy.co.uk
