Your first week with GLP-1: Get to know the changes

EXOMA Scientific Team · Publicado el 21 de mayo de 2026 · Actualizado el 24 de agosto de 2026

Discover what to expect during your first week with a GLP-1 agonist (Tirzepatide/Retatrutide). We explain the changes in appetite, energy and how to manage possible nausea so that your experience is smoother. Get informed to start with confidence!

Hello! Are you about to start your journey with a GLP-1 agonist, such as Tirzepatide or Retatrutide? It is completely normal to feel curious or even a little uncertain about what lies ahead. This guide is for you, so you know what is normal and how to prepare. We invite you to read our complete guide to get started if you want to go deeper into this topic.

What are GLP-1 agonists?

GLP-1 (glucagon-like peptide-1) agonists are medications that mimic the action of a natural hormone in your body. This hormone helps regulate blood sugar and the feeling of satiety, which can influence your appetite.

Changes in your appetite

One of the most notable changes you may feel is a decrease in your appetite. You will notice that you feel full faster and for longer. This is because GLP-1 works by slowing the emptying of your stomach and sending signals to your brain that you have already eaten enough.

• Less desire to eat: You might notice that cravings decrease and you don't feel the same urge to snack between meals.
• Smaller portions: You will likely feel satisfied with less food. Listen to your body and stop when you feel full.

Your energy level

Although GLP-1 can influence how your body processes energy, you should not experience a drastic change. Some people report feeling a little more tired at first, while others notice no difference. It is important that you pay attention to how you feel.

• Eat in a balanced way: Make sure to consume nutritious foods to keep your energy levels stable, even if you eat less.
• Hydration: Drinking enough water is key to your general well-being and can help you feel more energetic.

Possible nausea: What to do?

Nausea is one of the most common side effects at the start of treatment. Not everyone experiences it, but if it happens to you, there are ways to manage it.

• Start with low doses: Your doctor will surely instruct you to start with a small dose and gradually increase it. This helps your body adapt and reduces the likelihood of nausea.
• Light meals: Opt for low-fat, easy-to-digest foods. Avoid very spicy or heavy meals.
• Eat slowly: Take your time when eating. Chewing well and eating slowly can prevent discomfort.
• Avoid lying down right after eating: Try to wait at least 30 minutes before lying down to aid digestion.
• Ginger: Some people find relief with small amounts of ginger (in tea or candies), but always consult your healthcare professional first.

When to seek professional help?

Most side effects are mild and temporary. However, it is important to know when you should contact a healthcare professional.

• Severe nausea or constant vomiting: If the nausea is so intense that it prevents you from eating or drinking, or if you vomit repeatedly.
• Severe abdominal pain: Any severe abdominal pain that does not improve or worsens.
• Dehydration: Signs such as dry mouth, urinating less, or dizziness could indicate dehydration and require attention.

What is normal and what is not during the first week?

Normal:

• Decreased appetite and faster feeling of satiety.
• Mild and occasional nausea, especially after meals.
• A slight decrease in energy levels or passing fatigue.
• Changes in bowel habits (mild constipation or diarrhea).

Not normal (contact your healthcare professional):

• Uncontrollable nausea and vomiting that prevent eating or drinking.
• Intense and persistent abdominal pain.
• Dehydration (feeling very thirsty, dry mouth, urinating little).
• Allergic reactions (skin rashes, difficulty breathing, swelling).

In summary

• Your appetite will decrease and you will feel satisfied with smaller portions. Listen to your body.
• Nausea is possible, but it can be managed with adjustments to your diet and the way you eat. Start with low doses.
• If you experience severe or persistent side effects, always contact a health professional.

We hope this information is very useful to you as you begin your journey. Remember that each person is different and your experience may vary slightly. For a complete and more detailed guide, we invite you to visit our getting-started guide. You can also explore related products such as Tirzepatide 10 mg y Retatrutide 10 mg.