How many units is 100 mg of testosterone?

At 200 mg/mL, 100 mg is 50 units (0.5 mL) on a U-100 insulin syringe. At 100 mg/mL the same dose is 100 units (1 mL). The concentration printed on your vial determines the answer, so check the label before drawing.

What does 1 unit equal on a testosterone syringe?

It depends entirely on concentration. At 200 mg/mL, 1 unit = 2 mg. At 100 mg/mL, 1 unit = 1 mg. The syringe itself is always U-100 — 100 units to a millilitre — so the only variable is what is in the vial.

How long does a 10 mL vial of testosterone last?

A 10 mL vial at 200 mg/mL holds 2,000 mg: 20 weeks at 100 mg/week, 13 weeks at 150 mg, 10 weeks at 200 mg. At 100 mg/mL the same vial holds 1,000 mg and lasts half as long. Volume is not the only limit — your pharmacy sets a beyond-use date once the vial is entered.

What dose does the label actually state?

The Depo-Testosterone label states that for replacement in the hypogonadal male, 50 to 400 mg should be administered every two to four weeks, adjusted to the patient’s response and adverse reactions. It specifies intramuscular use only, deep in the gluteal muscle. This chart converts a prescribed dose; it does not recommend one.

Can I use an insulin syringe for testosterone?

Doses up to 100 units (1 mL) physically fit, but the label specifies intramuscular injection and a fixed 29–31G insulin needle at half an inch is both too fine to draw cold oil through and too short to reach gluteal muscle in most adults. Route and needle are your prescriber’s call.

Printable reference

Testosterone Dosage Chart

Every common dose converted to millilitres and U-100 syringe units, at both labelled strengths. Printable.

Reviewed September 2026

At 200 mg/mL: 1 unit = 2 mg
At 100 mg/mL: 1 unit = 1 mg
U-100 syringe: 100 units = 1 mL
Labelled range: 50–400 mg every 2–4 weeks

Find your prescribed dose in the left column, then read across to your vial’s concentration. The figure is what you draw on a U-100 insulin syringe; the millilitre value is for a luer-lock barrel.

A U-100 syringe is graduated so 100 units equals 1 mL, which is the conversion most people get wrong. Anything over 100 units will not fit an insulin barrel at all and needs a luer-lock syringe.

Dose to volume and syringe units

Testosterone cypionate or enanthate in oil. Units are on a U-100 insulin syringe; millilitres apply to any barrel.

Dose	200 mg/mLmL	200 mg/mLunits	100 mg/mLmL	100 mg/mLunits
20 mg	0.1	10	0.2	20
25 mg	0.125	12.5	0.25	25
30 mg	0.15	15	0.3	30
40 mg	0.2	20	0.4	40
50 mg	0.25	25	0.5	50
60 mg	0.3	30	0.6	60
70 mg	0.35	35	0.7	70
75 mg	0.375	37.5	0.75	75
80 mg	0.4	40	0.8	80
100 mg	0.5	50	1	100
120 mg	0.6	60	1.2	120luer-lock
125 mg	0.625	62.5	1.25	125luer-lock
140 mg	0.7	70	1.4	140luer-lock
150 mg	0.75	75	1.5	150luer-lock
160 mg	0.8	80	1.6	160luer-lock
175 mg	0.875	87.5	1.75	175luer-lock
200 mg	1	100	2	200luer-lock
250 mg	1.25	125luer-lock	2.5	250luer-lock
300 mg	1.5	150luer-lock	3	300luer-lock
400 mg	2	200luer-lock	4	400luer-lock

Greyed figures exceed 100 units and will not fit an insulin barrel — those volumes need a luer-lock syringe.

How long a vial lasts

Whole weeks only. Your pharmacy may set a shorter beyond-use date once a multi-dose vial is entered.

Weekly dose	10 mLat 200 mg/mL	10 mLat 100 mg/mL	1 mLat 200 mg/mL
50 mg/week	40 weeks	20 weeks	4 weeks
75 mg/week	26 weeks	13 weeks	2 weeks
100 mg/week	20 weeks	10 weeks	2 weeks
125 mg/week	16 weeks	8 weeks	1 weeks
150 mg/week	13 weeks	6 weeks	1 weeks
200 mg/week	10 weeks	5 weeks	1 weeks

Which syringe

Barrel	Reads in	Holds	Typical use
30-unit insulin	units	30 u / 0.3 mL	Small subcutaneous doses
50-unit insulin	units	50 u / 0.5 mL	Mid-range subcutaneous
100-unit insulin	units	100 u / 1 mL	Up to a full millilitre
1 mL luer-lock	millilitres	1 mL	Intramuscular, oil solutions
3 mL luer-lock	millilitres	3 mL	Larger intramuscular volumes

An insulin barrel is numbered in units and a luer-lock in millilitres. “Draw 0.5” means 0.5 mL on one and 0.5 units on the other — a hundredfold difference.

Frequently asked questions

How many units is 100 mg of testosterone?: At 200 mg/mL, 100 mg is 50 units (0.5 mL) on a U-100 insulin syringe. At 100 mg/mL the same dose is 100 units (1 mL). The concentration printed on your vial determines the answer, so check the label before drawing.
What does 1 unit equal on a testosterone syringe?: It depends entirely on concentration. At 200 mg/mL, 1 unit = 2 mg. At 100 mg/mL, 1 unit = 1 mg. The syringe itself is always U-100 — 100 units to a millilitre — so the only variable is what is in the vial.
How long does a 10 mL vial of testosterone last?: A 10 mL vial at 200 mg/mL holds 2,000 mg: 20 weeks at 100 mg/week, 13 weeks at 150 mg, 10 weeks at 200 mg. At 100 mg/mL the same vial holds 1,000 mg and lasts half as long. Volume is not the only limit — your pharmacy sets a beyond-use date once the vial is entered.
What dose does the label actually state?: The Depo-Testosterone label states that for replacement in the hypogonadal male, 50 to 400 mg should be administered every two to four weeks, adjusted to the patient’s response and adverse reactions. It specifies intramuscular use only, deep in the gluteal muscle. This chart converts a prescribed dose; it does not recommend one.
Can I use an insulin syringe for testosterone?: Doses up to 100 units (1 mL) physically fit, but the label specifies intramuscular injection and a fixed 29–31G insulin needle at half an inch is both too fine to draw cold oil through and too short to reach gluteal muscle in most adults. Route and needle are your prescriber’s call.

Sources

Next steps

Compare online TRT providersTelehealth platforms that prescribe and monitor, with pricing side by side.Full dosing protocolInteractive calculator, syringe visual, storage and monitoring.

Other charts

Educational reference, not medical advice. Converts a dose your prescriber has set; it does not select one. alphahealthfinder.com