If you’ve been prescribed Mounjaro (tirzepatide) to support your weight loss journey, you may be wondering why the dosage starts low and increases gradually over time. At Right Medicine Pharmacy, we help patients across Scotland understand their medications so they feel confident, supported, and in control.

In this guide, we’ll walk you through the Mounjaro dosage chart, explaining how the weekly injection schedule works, why your dose will increase over time, and who decides when it’s time to move to the next level.

Why the Dose Increases Gradually

Mounjaro is a once-weekly injectable medication that works by mimicking two natural hormones in your body to regulate blood sugar levels and reduce appetite. To reduce the risk of side effects—particularly nausea and digestive upset—the treatment starts at a low dose and is gradually increased every four weeks.

This approach gives your body time to adjust and ensures treatment remains both effective and tolerable.

The Mounjaro Dosage Chart

Below is a simple visual guide showing how the dose typically increases over the first several months of treatment:

Weeks Dosage Notes
Week 1–4 2.5 mg Starting dose – not for weight loss efficacy, but to allow the body to adjust
Week 5–8 5 mg First therapeutic dose – often where appetite suppression begins
Week 9–12 7.5 mg Increased dose if tolerated well
Week 13–16 10 mg Most patients continue seeing steady weight loss
Week 17+ 12.5 mg & beyond Based on response and tolerance; may go up to 15 mg in future weeks

Who Decides When Your Dose Increases?

At Right Medicine Pharmacy, your dosage is reviewed and adjusted in consultation with a trained healthcare professional. We don’t increase your dose automatically—your pharmacist or prescriber will:

  • –> Assess how well you’re tolerating the current dose

  • –> Ask about any side effects (e.g. nausea, bloating, constipation)

  • –> Review your weight loss progress and appetite changes

  • –> Make a personalised recommendation based on your response

In some cases, you may stay on a dose longer before increasing. In others, if you’re struggling with side effects, your pharmacist may advise pausing or delaying the next step up.

Easy to understand Mounjaro dosage chart

What to Expect at Each Stage

Week 1–4 (2.5 mg)

This is your “getting started” phase. You might not notice dramatic changes yet—but it’s helping your body prepare.

Week 5–8 (5 mg)

This is the first effective dose for weight loss. Many people notice appetite suppression, fewer cravings, and better control over portion sizes.

Week 9–12 (7.5 mg)

Weight loss tends to pick up here. You should begin to feel more confident in your routine, with manageable side effects.

Week 13–16 (10 mg)

This is where many patients settle into a steady rhythm. The higher dose helps maximise fat loss while maintaining tolerability.

Week 17+ (12.5 mg and above)

Depending on your progress, the dose may be increased again—but only if well tolerated and necessary for continued results.

Side Effects and Support

The most common side effects during dose escalation are:

  • –> Nausea

  • –> Diarrhoea or constipation

  • –> Fatigue

  • –> Reduced appetite

These are often temporary and improve as your body adjusts. If you experience more severe or persistent side effects, contact your nearest Right Medicine Pharmacy branch for support—we’re here to help.

View our Mounjaro dosage chart

Why In-Person Support Matters

Getting your Mounjaro prescription through a local clinic like Right Medicine Pharmacy means you’re never alone on your journey. You’ll receive:

  • –> A face-to-face consultation

  • –> Personalised dose scheduling

  • –> Guidance on side effect management

  • –> A consistent, friendly team across multiple locations in Scotland

Unlike online-only providers, we get to know you—and you can walk in for advice any time.

Clarity and Success

The Mounjaro dosage chart is designed to make your weight loss journey clearer and more successful. By gradually increasing your dose over time, we help you balance effectiveness with comfort, avoiding unnecessary side effects and supporting long-term results. Get in touch to find out more.

If you’re considering starting Mounjaro or would like to review your current dosage, book a consultation with Right Medicine Pharmacy today. Our team is ready to guide you every step of the way—from first dose to lasting results.

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This blog was written on behalf of Right Medicine Pharmacy by Pharmacy Mentor.