Dosing Protocols

Reference tables for men who already have a prescription and a vial. Each page converts a prescribed dose into the volume and syringe units you draw, quotes the labelled range, and shows how long the vial lasts.

These pages do not recommend a dose. That decision belongs to your prescriber.

Testosterone Cypionate

Reading a U-100 syringe

A U-100 insulin syringe is graduated so that 100 units equals 1 mL. Every conversion below follows from that one fact. What a unit is worth depends entirely on the concentration of the vial in front of you.

Units to draw, by vial concentration
Dose	50 mg/mL	100 mg/mL	200 mg/mL	250 mg/mL
1 unit =	0.5 mg	1 mg	2 mg	2.5 mg
10 mg	20u	10u	5u	4u
20 mg	40u	20u	10u	8u
25 mg	50u	25u	12.5u	10u
50 mg	100u	50u	25u	20u
75 mg	150—over 1 mL	75u	37.5u	30u
100 mg	200—over 1 mL	100u	50u	40u
125 mg	250—over 1 mL	125—over 1 mL	62.5u	50u
150 mg	300—over 1 mL	150—over 1 mL	75u	60u
200 mg	400—over 1 mL	200—over 1 mL	100u	80u

Greyed figures exceed 1 mL and will not fit any insulin barrel — those doses need a luer-lock syringe.

Insulin barrel or luer-lock?

“Draw 0.5” means two different things. An insulin barrel is numbered in units; a luer-lock in millilitres. On one that instruction is 0.5 mL, on the other it is a hundredth of that. Check which unit your barrel is printed in before you draw.

Barrel	Numbered in	Route	Reached for when
30-unit insulin (0.3 mL)	units	Subcutaneous	Small aqueous volumes where every unit matters. The finest resolution of the three insulin barrels.
50-unit insulin (0.5 mL)	units	Subcutaneous	Mid-range aqueous doses that would crowd a 30-unit barrel.
100-unit insulin (1 mL)	units	Subcutaneous	Doses near a full millilitre. Marks are 2 units apart, so it reads coarser than the smaller barrels.
1 mL luer-lock	mL	Intramuscular	Oil-based solutions and intramuscular injection, where a detachable needle lets you draw through a wide gauge and inject through a finer one.
3 mL luer-lock	mL	Intramuscular	Larger intramuscular volumes, or when drawing from several vials.

These pages are educational reference, not medical advice. They convert a dose your prescriber has set; they do not choose one.