First Week on GLP-1: What to Expect, Common Reactions, and How to Get Through It

You packed your medication, landed in Phuket, and gave yourself your first injection. By day two you are lying in your hotel room in Kata or Kamala wondering whether this is supposed to feel this bad. The nausea hit harder than you expected, the humidity is making everything worse, and your usual GP is twelve time zones away.

Week one on a GLP-1 is genuinely uncomfortable for many people, but uncomfortable and dangerous are two different things. This guide walks you through what is normal, what is not, and exactly what to do if things feel like they are going sideways on the island.

Why the First Week on GLP-1 Feels So Rough

GLP-1 medications slow how fast food leaves your stomach. That is why you feel full on very little and why nausea shows up so reliably in week one. Your gut has not seen this before, and it takes time to adjust.

Semaglutide and tirzepatide both cause this effect. Tirzepatide also acts on a second receptor, which can make the early side-effect profile feel slightly different from person to person. The principle is the same: your body is adapting to a drug that changes how it processes food and signals hunger.

The starting dose is deliberately low. That is not an accident, and skipping ahead is one of the faster ways to make week two significantly worse.

Your Starting Dose and Why the Titration Schedule Exists

Every GLP-1 protocol starts low and increases gradually over weeks. This step-up schedule exists entirely to protect your gut while your body adjusts. Your prescribing doctor sets this timeline, and it should not be changed without speaking to them first.

If you are in Phuket and your prescribing clinic is elsewhere, you can get a prescription refill in Phuket or titration guidance from a walk-in physician on the island. Do not skip steps. The schedule is not a formality.

Common Reactions in Week One

Nausea is the most common reaction at the starting dose. It is usually mild to moderate and tends to peak again with each subsequent dose increase, not only in week one.

Alongside nausea, most people notice reduced appetite, some fatigue, and loose stools or mild diarrhoea. Injection site redness is normal and usually settles within a day. Headache and dizziness can also occur, particularly if you are not eating enough.

In Phuket’s heat, dehydration compounds every one of these symptoms faster than most visitors from northern Europe or North America would expect from experience at home. This is the thing most people do not anticipate.

What to Eat and Avoid in Week One

Small meals. Plain food. This is not the week to work through a Patong buffet or order a coconut milk curry from a beach club in Surin.

High-fat foods slow gastric emptying even further and compound the nausea the medication is already causing. Spicy food irritates a stomach that is already sensitive. Alcohol worsens nausea and affects blood sugar management, which matters more now that you are on a GLP-1.

In practical Phuket terms: plain jasmine rice, steamed fish, clear soups without coconut, boiled eggs, and fresh fruit tend to sit well. Most of this is easy to find across the island, from a local shop-house in Chalong to a hotel restaurant in Bang Tao. Leave the green curry for week three.

Practical Tips for Getting Through Week One

Inject at a consistent time each week. Some people find injecting in the evening means the worst of the nausea passes overnight. Consistency matters for both how the drug works and for predicting when you will feel rough.

Eat before you feel hungry, not after. Waiting until you are very hungry and then eating a full plate is more likely to trigger nausea than eating small amounts on a regular schedule. Ginger tea has some evidence behind it for nausea relief and is easy to find anywhere on the island.

Staying well hydrated is not optional here. Phuket’s heat will accelerate dehydration, and dehydration will make dizziness and fatigue significantly worse. Keep a brief food and symptom note as well. If things escalate, that record helps a doctor understand your pattern quickly.

Starting GLP-1 While in Phuket: What Expats and Long-Stay Visitors Need to Know

Starting GLP-1 medication while travelling is not the ideal scenario. It is also genuinely common among people on longer stays. If you are a digital nomad in Rawai, a retiree in Chalong, or someone on a multi-month visa, you may not have a home GP to lean on during week one.

The most important thing is to start with a proper physician assessment. GLP-1 medications are not appropriate for everyone, including people with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2. People with a history of pancreatitis should discuss this with their prescribing doctor before starting, as the drug class carries a pancreatitis warning and has not been well studied in this group. A licensed physician needs to screen for contraindications before prescribing.

Takecare Clinic Phuket offers walk-in consultations with no appointment needed. An English-speaking doctor in Phuket can assess whether you are a suitable candidate and advise on a safe starting protocol. If you are already on a GLP-1 prescribed at home and need support while you are here, bring your current medication packaging or prescription details. For patients who are too unwell to travel to the clinic, a doctor hotel visit in Phuket is available across the island.

Warning Signs That Need Same-Day Attention

Most first-week symptoms are uncomfortable but manageable. A few are not.

Seek same-day assessment if you have severe upper abdominal pain, especially if it radiates to your back. This can be a sign of pancreatitis, a rare but serious complication. Also seek care if you cannot keep fluids down, if you are dizzy and cannot stand safely, or if your heart is racing alongside the other symptoms.

Low blood sugar is less common on GLP-1 medications alone but can occur if you are also on certain diabetes medications or simply not eating enough. Symptoms include shakiness, sudden sweating, confusion, and rapid heartbeat. If that happens, have something sugary immediately and see a doctor the same day.

These are not reasons to stop your medication without advice. They are reasons to get assessed. Takecare Clinic Phuket is open as a walk-in with extended hours, and a physician can rule out serious causes and keep you on track. If you are unsure whether your symptoms need a clinic visit, telemedicine in Phuket is also available.