If you are splitting doses of Wegovy, Ozempic, or Mounjaro, choosing the right pen is one of the most important decisions you will make. Not all pens are created equal — they contain different concentrations of medication, different volumes, and deliver different amounts per click. Picking the wrong pen could mean you cannot reach your target dose, or that you waste expensive medication.
This guide walks you through the key differences between pens and helps you find the best match for your prescribed dose.
Why Concentration Matters
Each click on an injection pen delivers a fixed amount of medication — but that amount varies from pen to pen. A higher-concentration pen delivers more medication per click than a lower-concentration one. This means two different pens can require very different click counts to deliver the same dose.
When you are dose-splitting, you need to know exactly how many clicks correspond to your target dose. That is why the first step is always to identify which pen you have and what its concentration is.
Wegovy Pens in Detail
Wegovy (semaglutide) comes in four different pen strengths. Each pen has its own concentration and therefore its own milligrams-per-click value:
| Pen | Volume | mg/click | Possible Doses |
|---|---|---|---|
| 0.5 mg | 1.5 mL | 0.0134 | 0.25 mg or 0.5 mg |
| 1 mg | 3 mL | 0.0134 | 0.5 mg or 1 mg |
| 1.7 mg | 3 mL | 0.0227 | 1 mg or 1.7 mg |
| 2.4 mg | 3 mL | 0.032 | 0.25 mg to 2.4 mg |
The 0.5 mg pen and the 1 mg pen share the same concentration (0.0134 mg/click), but the 1 mg pen contains twice as much medication. Both are well suited for lower doses like 0.25 mg and 0.5 mg.
The 1.7 mg pen has a higher concentration (0.0227 mg/click), making it a good choice if you are titrating up and need doses in the 1 mg to 1.7 mg range.
The 2.4 mg pen is the most versatile. At 0.032 mg per click, it can deliver anything from 0.25 mg all the way up to the full 2.4 mg dose. If you are dose-splitting and want flexibility, the 2.4 mg pen is often the best option.
Mounjaro Pens
Mounjaro (tirzepatide) works a bit differently. All Mounjaro pens have exactly 60 clicks, regardless of strength. This makes the math straightforward: you choose the pen strength that matches your target dose, then calculate the number of clicks as a fraction of 60.
For example, if you have a 5 mg pen and want 2.5 mg, you dial half the pen's clicks — that is 30 clicks. Always choose the pen strength closest to your desired dose for the best precision.
Ozempic Pens
Ozempic (also semaglutide, but dosed differently from Wegovy) has a consistent concentration of 0.01 mg per click across all pens. The difference between Ozempic pens is the maximum dose they can deliver.
Choose your Ozempic pen based on the highest dose you need. Since all pens share the same concentration, the click calculation is identical — you just need to make sure the pen contains enough medication for your dose.
Practical Advice for Choosing Your Pen
- Match the pen to your dose: Choose a pen where your target dose falls within the pen's range. Do not use a pen that is too small for your intended dose.
- Think about precision: Lower-concentration pens give you more clicks per milligram, making it easier to fine-tune doses. Higher-concentration pens require fewer clicks, but each click "counts for more."
- Storage matters: A Wegovy pen can be used for up to 8 weeks after first use, as long as it is stored correctly (below 30 degrees Celsius, protected from light). When dose-splitting, it is important to track when you first opened the pen.
- Reduce waste: If you dose-split from a larger pen, you get more doses per pen and reduce waste of expensive medication.
Let ClickDose Do the Math
You do not need to sit with a calculator and concentration tables. ClickDose shows you the exact number of clicks for any combination of pen and dose. Select your medication, choose your pen strength, and the app tells you precisely how many clicks to dial.
This eliminates guesswork and reduces the risk of dosing errors — especially important when you are dose-splitting and precision is everything.