Why should I split my TRT dose into multiple injections?

Splitting your weekly testosterone dose into two or more smaller injections produces more stable blood testosterone levels, reducing the peaks and troughs of once-weekly dosing. Many men report better energy, mood, and libido consistency on twice-weekly injections versus once-weekly at the same total dose.

How do I calculate my split dose?

Divide your total weekly dose by the number of injections per week. For example: 200mg/week split into 2 injections = 100mg per injection. At 200mg/mL concentration, that is 0.5mL per injection. Use the split dose calculator to automatically calculate both the mg per injection and the exact mL volume.

Can I use the split dose calculator for peptides?

Yes. The split dose calculator works for any compound where you want to divide a total weekly dose into multiple smaller injections. This is useful for peptides like BPC-157 or TB-500 that are often dosed twice daily or multiple times per week.

What is the difference between once-weekly and twice-weekly TRT injections?

Once-weekly TRT produces a larger peak after injection and a lower trough before the next dose. Twice-weekly TRT creates a smaller swing, keeping levels more consistent. Most TRT specialists prefer twice-weekly dosing for testosterone cypionate and enanthate. The split dose calculator helps you find the right per-injection volume.

Does splitting TRT doses reduce side effects?

For many patients, yes. High peaks after a single large weekly injection can cause temporary side effects including water retention, elevated hematocrit, or mood swings. Smaller, more frequent doses reduce peak testosterone and estrogen levels, which often improves tolerability and reduces aromatization.

How do I split a 200 mg/week testosterone dose?

Divide the weekly total by the number of injections. Twice-weekly: 100 mg per shot (0.5 mL at 200 mg/mL). Three times per week: about 66.7 mg per shot (0.33 mL). Every other day: about 57 mg per shot (0.29 mL). Daily: about 28.6 mg per shot (0.14 mL). More frequent splits produce more stable blood levels but require smaller, more precise draws.

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Split Dose Calculator

Calculate split doses for semaglutide, tirzepatide, and testosterone. Divide your weekly dose into multiple injections for more stable blood levels.

Compound

Total Weekly Dose (mg)

Injection Schedule

Vial Size (mg)

BAC Water Added (mL)

Dose per Injection

0.500 mg

2 injections per week

Why Split Dosing?

Splitting your weekly dose into multiple smaller injections helps maintain more stable blood levels throughout the week, reducing the peaks and troughs that cause side effects.

For GLP-1 medications (semaglutide, tirzepatide):

Smaller, more frequent doses lower peak drug levels, which can significantly reduce nausea, vomiting, and other GI side effects. Some clinicians prescribe split dosing for compounded semaglutide specifically to improve tolerability during titration.

For TRT (testosterone cypionate, enanthate):

More frequent injections reduce the peak-to-trough ratio, which can lower estrogen conversion (less need for AI), reduce acne and oily skin, and improve mood stability. Most TRT-optimized protocols use at least twice-weekly injections, with some users preferring every-other-day or daily microdosing.

Some people take this further and move to daily microdosing. See our microdosing TRT guide for full daily protocols.

See How Split Dosing Affects Your Levels

Use the Half-Life Visualizer to compare weekly vs. split dose blood curves

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For educational and research purposes only. This calculator provides estimates based on standard formulas.

Always verify calculations with your healthcare provider before use. We assume no liability for dosing errors, adverse events, or outcomes resulting from use of this tool.

Weekly dose → per-injection

Weekly dose	Twice weekly (÷2)	Every other day (÷3.5)	Daily (÷7)
2 mg (GLP-1 microdose)	1 mg	~0.57 mg	~0.29 mg
7 mg	3.5 mg	2 mg	1 mg
100 mg (TRT)	50 mg	~28.6 mg	~14.3 mg
150 mg (TRT)	75 mg	~42.9 mg	~21.4 mg
200 mg (TRT)	100 mg	~57.1 mg	~28.6 mg

Same math for any compound — divide your weekly dose by shots per week. Use the calculator above for your exact numbers.

How to Use This Calculator

Select your compound

Choose from semaglutide, tirzepatide, testosterone, or retatrutide

Enter weekly dose

Your total prescribed weekly dose in mg

Pick your schedule

Choose times per week or every X days

View your split dose

See per-injection dose and optional syringe units

See your split dose blood levels in real-time

Regimen visualizes your blood levels based on every dose you log, with smart reminders for each injection day.

Visualize blood levels with split dosing
Reminders for each injection day
Track weight, side effects, and progress
Private, secure health data

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Regimen app screenshot showing protocol tracking

Common Questions

Related Tools

Half-Life Visualizer

See how split dosing changes your blood concentration curve

GLP-1 Dose Calculator

Calculate exact syringe units for semaglutide and tirzepatide

GLP-1 Titration Planner

Plan your dose escalation schedule with exact dates

TRT Dose Calculator

Calculate TRT injection doses for cypionate and enanthate

Split Dose Calculator

Why Split Dosing?

See How Split Dosing Affects Your Levels

Weekly dose → per-injection

How to Use This Calculator

Select your compound

Enter weekly dose

Pick your schedule

View your split dose

See your split dose blood levels in real-time

Common Questions

What is split dosing?

Is split dosing semaglutide safe?

Why do TRT users split their dose?

How often should I inject testosterone?

Does split dosing reduce side effects for GLP-1s?

What about microdosing GLP-1 medications?

How do I calculate syringe units for split doses?

Can I use this calculator for other compounds?

How do I split a 200 mg/week testosterone dose?

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