PT-141: which line to draw to

Enter your PT-141 vial amount, the water you added and your dose. PT-141 is dosed in mg; the syringe shows exactly where to stop. New to this?

Your line shows up here.

Fill in the vial, water and dose boxes.

Approved drug. Sold as Vyleesi, for low sexual desire in women before menopause.

In the vial

mg

Water added

mL

Your dose

mgmcg

Syringe

What do these boxes mean?

In the vial: The amount of powder in the vial before you add anything, e.g. “5 mg”. It’s on the label or the box.
Water added: How much bacteriostatic water you mixed in. It doesn’t change how much peptide you get, only how strong the mix is. More water makes each dose a bigger amount that’s easier to measure.
Your dose: How much peptide you want per injection, from your prescription or plan. Not the number of units on the syringe; that’s what we work out.
Syringe: Check the packet: 1 mL, 0.5 mL or 0.3 mL (sometimes written 100, 50 or 30 units). All are U-100: 100 units is 1 mL. Smaller syringes measure small doses more accurately.

When does this vial expire?

Mixed on

Good for (days)

PT-141 at a glance

Evidence: Approved drug. Sold as Vyleesi, for low sexual desire in women before menopause.
Vial sizes: 2, 5, 10 mg
Usual dose range: 0.5–2 mg
How often: As needed, max 1×/24h
Unmixed: Freezer −20°C
After mixing: Fridge 2–8°C, use within 28 days

PT-141 units to mg chart

Syringe units on any U-100 insulin syringe (100 units = 1 mL), worked out by the same engine as the calculator. Your own vial and water may differ: use the calculator for your numbers.

2 mg vial + 1 mL water (2 mg per mL)
Dose	Units	mL
0.5 mg	25	0.25
1 mg	50	0.5
1.75 mg	87.5	0.875
2 mg	100	1

5 mg vial + 2 mL water (2.5 mg per mL)
Dose	Units	mL
0.5 mg	20	0.2
1 mg	40	0.4
1.75 mg	70	0.7
2 mg	80	0.8

10 mg vial + 3 mL water (3.3 mg per mL)
Dose	Units	mL
0.5 mg	15	0.15
1 mg	30	0.3
1.75 mg	52.5	0.525
2 mg	60	0.6

PT-141 questions

How many units is 0.5 mg of PT-141?

With a 2 mg vial mixed with 1 mL of bacteriostatic water, 0.5 mg is 25 units (0.25 mL) on a U-100 insulin syringe. A different vial size or amount of water changes this, so check it with your own numbers.

How much water do I add to a 2 mg PT-141 vial?

1 mL of bacteriostatic water is common, which makes 2 mg per mL. More water makes each dose a bigger amount that is easier to measure; it doesn't change how much is in the vial.

How long does mixed PT-141 last?

Once mixed, keep it at fridge temperature, 2–8°C and use it within 28 days. Unmixed powder: freezer −20°c.

What is PT-141?

PT-141 (bremelanotide) is approved as Vyleesi, for low sexual desire in women before menopause. It acts on melanocortin receptors in the brain, not on blood flow like Viagra.

The approved use

The approved dose is 1.75 mg under the skin at least 45 minutes before sex, no more than once in 24 hours and no more than 8 times a month.

What to watch for

Nausea is very common, especially with the first dose. It can briefly raise blood pressure, so it isn’t for people with uncontrolled high blood pressure or heart disease. Repeated use can darken patches of skin.