Split Dose Calculator
Divide your weekly injection dose into multiple shots. Calculate per-injection amounts, volumes, and syringe units for any split dosing protocol.
Typical TRT: 80-200 mg/week
Per-injection dose
Inject every 3-4 days — e.g. Monday & Thursday
Volume per injection
Injections
Between injections
Why Split Dosing?
For GLP-1 Medications
Splitting your weekly GLP-1 dose into two smaller injections can reduce nausea and GI side effects by lowering peak drug levels. This is especially useful during titration when your body is adjusting. Some clinicians prescribe split dosing for compounded semaglutide to improve tolerability.
For TRT
More frequent injections reduce the peak-to-trough ratio, which means more stable blood levels. This can reduce estradiol conversion (less need for an AI), reduce acne and oily skin, improve mood stability, and minimize the "crash" feeling before your next injection. Most TRT-optimized protocols use at least twice-weekly injections.
Common Split Dose Protocols
| Protocol | Weekly Dose | Split | Per Injection | Schedule |
|---|---|---|---|---|
| TestC TRT (standard) | 140 mg | 2x/week | 70 mg | Mon & Thu |
| TestC TRT (optimized) | 140 mg | 3x/week | 46.7 mg | Mon / Wed / Fri |
| TestC TRT (daily) | 140 mg | Daily | 20 mg | Every morning |
| Semaglutide (split) | 1.0 mg | 2x/week | 0.5 mg | Mon & Thu |
| TestE (standard) | 125 mg | 2x/week | 62.5 mg | Mon & Thu |
Worked Example
Scenario: You inject 140mg/week of Testosterone Cypionate from a 200mg/mL vial, split into 2 injections per week.
Per-injection dose: 140 mg ÷ 2 = 70 mg
Per-injection volume: 70 mg ÷ 200 mg/mL = 0.35 mL
Syringe units (U-100): 0.35 mL × 100 = 35 units
Schedule: Monday and Thursday mornings
Frequently Asked Questions
What is split dosing?+
Split dosing means dividing your total weekly dose into two or more smaller injections spread throughout the week, rather than injecting the full amount at once. This keeps your blood levels more stable.
Is split dosing semaglutide safe?+
Yes — splitting your weekly GLP-1 dose is safe and can reduce side effects. Some clinicians actively prescribe this approach, especially with compounded semaglutide during titration. Always follow your prescriber's guidance.
Why do TRT users split their dose?+
More frequent, smaller injections keep testosterone levels more stable. This reduces estradiol spikes (potentially eliminating the need for an AI), reduces acne and oily skin, improves mood stability, and avoids the energy crash before your next injection.
How often should I inject testosterone?+
Most TRT-optimized protocols use at least twice-weekly injections. Three times per week (MWF) or every other day (EOD) provide even more stable levels. Daily SubQ microdosing is growing in popularity. Your ideal frequency depends on the ester — shorter esters benefit more from frequent injections.
Does split dosing reduce side effects for GLP-1s?+
It can. Nausea and GI side effects are related to peak drug levels. By splitting the dose, you lower the peak concentration after each injection, which many users find reduces nausea, especially during the early weeks of titration.
What about microdosing GLP-1 medications?+
Microdosing (daily or every-other-day small doses) is an emerging approach, primarily used with compounded semaglutide. Some users report better tolerability and more consistent appetite suppression. This is off-label — discuss with your prescriber.
How do I calculate syringe units for split doses?+
Divide your per-injection dose (mg) by your vial concentration (mg/mL) to get the volume in mL. Then multiply by 100 to convert to U-100 insulin syringe units. This calculator does the math for you.
Can I use this calculator for other compounds?+
Yes — this works for any injectable medication with a weekly dosing schedule. Select your compound from the dropdown, or use any compound where you know your total weekly dose.
Related Tools
Doseline provides informational tools only. It is not a medical device and does not provide medical advice. Always consult a qualified healthcare provider.
Like this tool?
It's better in the app.
The app is coming soon. Join the waitlist to be first to try Doseline — with all 17 tools, reminders, and protocol tracking built in.