You've completed your consultation, received your medication, and you're ready to take your first dose of semaglutide or tirzepatide. If you're feeling nervous or wondering what to expect, you're not alone. Most of our patients have the same questions before their first injection.

Here's everything you need to know about your first GLP-1 dose, from the injection itself to what you'll feel in the hours and days that follow.

Before Your First Injection: What You Need

Make sure you have everything ready:

• Your GLP-1 medication (refrigerated, not frozen)
• Alcohol wipes
• Syringe with needle (provided with your medication)
• Sharps container for safe disposal
• Clean, flat surface to work on
• Injection instructions or tutorial video

Pro tip: Watch the injection tutorial video at least once before your first dose. Seeing the process helps reduce anxiety.

The First Injection: Step-By-Step

1. Choose Your Injection Site

You can inject semaglutide or tirzepatide into:

• Abdomen: Most common, at least 2 inches away from belly button
• Thigh: Front or outer thigh, mid-thigh area
• Upper arm: Back of upper arm (may need assistance)

Rotate injection sites: Use a different spot each week to prevent irritation or lumps.

2. Prepare Your Injection

• Wash your hands thoroughly
• Remove medication from refrigerator (let it sit for 5-10 minutes to reach room temperature)
• Clean injection site with alcohol wipe and let dry
• Draw up the correct dose as instructed by your provider
• Remove air bubbles by gently tapping the syringe

3. Administer the Injection

• Pinch a fold of skin at your injection site
• Insert the needle at a 90-degree angle (or 45 degrees if very thin)
• Push the plunger slowly and steadily
• Remove the needle and release the skin
• Apply gentle pressure with a clean cotton ball or gauze (don't rub)
• Dispose of the needle in your sharps container immediately

How long does it take? The entire process takes less than 60 seconds once you're comfortable with it.

Does it hurt? Most patients report minimal to no pain. The needles are very thin (similar to insulin needles). You may feel a slight pinch or pressure, but it's typically much easier than expected.

What to Expect: First 24 Hours

Immediate Effects (0-6 Hours)

Right after your first injection, you likely won't feel much of anything. This is completely normal. GLP-1 medications work gradually, not immediately.

What you might notice:

• Slight tenderness at injection site (normal)
• Mild fatigue or drowsiness (some patients)
• Reduced appetite starting 4-6 hours post-injection (some patients)
• Nothing at all (also completely normal!)

What you probably won't notice:

• Dramatic appetite suppression (this builds over time)
• Immediate weight loss
• Severe side effects (rare on the starting dose)

First Day (6-24 Hours)

As the medication begins working, you may start to notice subtle changes:

Common experiences:

• Reduced hunger: You may not feel as hungry at your usual meal times
• Earlier fullness: You might feel satisfied with smaller portions
• Mild nausea: Some patients experience light queasiness, especially after eating
• Fatigue: Feeling more tired than usual is common in the first week
• Thirst: Increased thirst is normal—drink plenty of water

Less common but normal:

• Mild headache
• Slight dizziness
• Constipation or diarrhea
• Bloating or gas

What to Expect: First Week

Days 2-3: Medication Reaches Peak Levels

Semaglutide and tirzepatide reach peak concentration in your bloodstream 1-3 days after injection. This is when you'll likely notice the most pronounced effects:

• Appetite suppression: Food may sound less appealing, and you'll feel full faster
• Reduced cravings: The constant thoughts about food may quiet down
• Nausea (if it occurs): Usually peaks around day 2-3, then improves
• Energy changes: Some fatigue is normal as your body adjusts

Days 4-7: Stabilization

By the end of your first week, your body begins adapting to the medication:

• Nausea typically improves or resolves
• Energy levels start to normalize
• Appetite suppression continues but feels more manageable
• You may notice 1-3 pounds of initial weight loss (often water weight)

Starting Doses: What's Normal

Semaglutide Starting Dose

Week 1-4: 0.25 mg once weekly

This is a sub-therapeutic dose designed to help your body adjust with minimal side effects. You may notice some appetite reduction, but significant weight loss is not expected at this dose.

Tirzepatide Starting Dose

Week 1-4: 2.5 mg once weekly

Similar to semaglutide, this starting dose is lower than the therapeutic dose. It helps minimize side effects while your body adapts to the medication.

Important: Don't be discouraged if you don't see dramatic results in the first month. The starting dose is intentionally low. Your provider will gradually increase your dose every 4 weeks to optimize results while minimizing side effects.

Managing Common First-Dose Side Effects

Nausea

If you experience nausea:

• Eat smaller, more frequent meals instead of large meals
• Avoid greasy, fried, or very rich foods
• Stay hydrated with water or ginger tea
• Eat bland foods (crackers, toast, rice) if needed
• Don't lie down immediately after eating
• Consider taking your injection in the evening (some patients tolerate it better)

When to contact your provider: If nausea is severe, persistent, or accompanied by vomiting that prevents you from staying hydrated.

Fatigue

If you feel tired:

• Prioritize sleep (aim for 7-9 hours)
• Stay hydrated—dehydration worsens fatigue
• Eat adequate protein to maintain energy
• Light exercise (walking) can actually boost energy
• Be patient—energy typically improves after week 1-2

Constipation

If you experience constipation:

• Increase water intake (aim for 8-10 glasses daily)
• Add fiber-rich foods (vegetables, fruits, whole grains)
• Stay physically active
• Consider a gentle fiber supplement or stool softener
• Avoid straining—contact your provider if severe

What NOT to Worry About

It's normal if you:

• Don't feel anything dramatic after your first dose
• Don't lose weight in the first week
• Experience mild, temporary side effects
• Feel nervous about the injection (it gets easier every week)
• Have questions—your provider is here to help!

It's NOT normal if you:

• Experience severe, persistent vomiting
• Have severe abdominal pain
• Notice signs of allergic reaction (rash, swelling, difficulty breathing)
• Have symptoms of pancreatitis (severe upper abdominal pain radiating to back)
• Experience vision changes or severe headaches

When in doubt, contact your provider immediately.

Tips for Success on Your First Dose

1. Time Your Injection Strategically

Many patients prefer to inject on Friday or Saturday evening so they can rest over the weekend if they experience fatigue or nausea.

2. Eat a Light Meal Before Injecting

Having a small, bland meal in your stomach can help reduce nausea. Avoid injecting on a completely empty stomach.

3. Stay Hydrated

Drink plenty of water throughout the week. Dehydration can worsen side effects like fatigue, headaches, and constipation.

4. Keep a Journal

Track your symptoms, appetite changes, energy levels, and weight. This helps you and your provider optimize your treatment.

5. Be Patient with Yourself

Your body is adjusting to a new medication. Give yourself grace, rest when needed, and remember that side effects typically improve after the first 1-2 weeks.

What Happens Next: Weeks 2-4

After your first dose, you'll continue with the same starting dose for 3 more weeks (total of 4 weeks). During this time:

• Side effects typically decrease or resolve
• Appetite suppression becomes more consistent
• You may lose 2-5% of your body weight
• Your body adapts to the medication
• You'll prepare for your first dose increase

Week 5: Your provider will increase your dose to the next level (semaglutide 0.5 mg or tirzepatide 5 mg). You may experience mild side effects again as your body adjusts to the higher dose, but they're typically less intense than the first week.

Real Patient Experiences: First Dose Stories

Sarah, 42: "I was so nervous about the injection, but it was honestly painless. I felt a little tired that evening and had mild nausea the next day, but nothing severe. By day 3, I noticed I wasn't thinking about food constantly. That was the biggest change for me."

Michael, 38: "I didn't feel much of anything the first day. By day 2, I noticed I was full after eating half my usual portion. I had some fatigue the first week, but it improved quickly. Lost 3 pounds in the first month on the starting dose."

Jennifer, 51: "The injection was way easier than I expected. I had mild nausea for about 3 days, but eating smaller meals helped. The appetite suppression was noticeable by day 2. I'm so glad I started this journey."

Your Support System

Remember, you're not alone in this journey. At Syren Medical, you have:

• Secure messaging: Contact your provider anytime with questions
• Injection tutorials: Video guides available 24/7
• Side effect management: Evidence-based strategies to minimize discomfort
• Regular check-ins: Your provider monitors your progress and adjusts as needed

The Bottom Line

Your first semaglutide or tirzepatide dose is an important milestone in your weight loss journey. While you may experience some mild side effects, most patients find them manageable and temporary. The starting dose is designed to help your body adjust gradually, setting you up for long-term success.

Be patient, stay hydrated, listen to your body, and don't hesitate to reach out to your provider with any concerns. You've got this!

Medical Disclaimer: This content is for educational purposes only and does not constitute medical advice. Always follow your healthcare provider's specific instructions for your medication. Contact your provider immediately if you experience severe or concerning symptoms. Individual experiences with GLP-1 medications vary.