Enter the vial size and the bacteriostatic water you added to get the concentration and the syringe units for a quantity on a U-100 syringe. The only PT-141 dose with a source is the Vyleesi label's 1.75 mg — a prescription autoinjector, not a research vial — so this page converts that figure for reference and states no research-grade dose. The compound itself is covered in the PT-141 guide.
A 10 mg vial of PT-141 reconstituted with 2 mL of bacteriostatic water gives a concentration of 5.0 mg/mL, or 50 mcg per unit on a U-100 syringe. For a 1.75 mg dose, draw the syringe to 35.0 units (0.35 mL). At that dose the vial provides about 5.71 doses.
Defaults: 10 mg is the most common labelled vial among the PT-141 tests on file, 21 Sep 2026 (246 of 262); 2 mL was chosen for simple arithmetic; 1.75 mg is the dose in the Vyleesi prescribing information (as needed, subcutaneous), used here for arithmetic only.
Draw the syringe up to
That's one 1.75 mg dose. Add 2 mL of water to your 10 mg vial first.
PT-141 has 263 independent lab tests on file at Peptigrity, averaging 99.70% HPLC purity across the tests that report one. Purity is not net content: a clean certificate confirms what is in a vial, not how much. See the PT-141 lab-test records.
PT-141 and bremelanotide are the same compound: the compound page names it “PT-141 (Bremelanotide)”, a synthetic cyclic 7-amino-acid melanocortin receptor agonist derived from Melanotan II and selective for MC4R, and FDA-approved as Vyleesi for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. That approval is why PT-141, unlike most compounds in this calculator suite, has a dose with a source. It is also why the dose needs care: it belongs to the Vyleesi prescription product, and research-grade PT-141 is a different product.
The table sets out what the compound page states (page last updated August 2026, read 21 September 2026), and at what level of evidence.
| Question | What the compound page states | Evidence level |
|---|---|---|
| What is it? | A synthetic cyclic 7-amino-acid melanocortin receptor agonist, derived from Melanotan II, selective for MC4R | Established pharmacology |
| Is PT-141 bremelanotide? | Yes — “PT-141 (Bremelanotide)”, sold by prescription as Vyleesi | Chemical identity |
| Approved use? | Vyleesi, FDA-approved in 2019 for acquired, generalized HSDD in premenopausal women | FDA-approved; Phase 3 RECONNECT trials |
| An approved dose? | 1.75 mg subcutaneously, as needed, at least 45 minutes before anticipated sexual activity; no more than one dose in 24 hours and no more than 8 doses per month | Vyleesi prescribing information |
| Route? | Subcutaneous self-administration from a 1.75 mg autoinjector | Vyleesi prescribing information |
| A research-grade dose? | None — “Research-grade use is not FDA-approved.” | None |
Peptigrity does not recommend a PT-141 dose. The table below prints the Vyleesi prescribing information exactly as the compound page quotes it (last updated August 2026), beside an empty research-grade column: no source states a dose for research-grade PT-141, and this page does not supply one.
| Field | Vyleesi (prescription, FDA-approved) | Research-grade PT-141 |
|---|---|---|
| Amount | 1.75 mg | — none stated |
| Route and form | Subcutaneous, from a 1.75 mg autoinjector | — none stated |
| Timing | As needed, at least 45 minutes before anticipated sexual activity | — none stated |
| Limits | No more than one dose in 24 hours; no more than 8 doses per month | — none stated |
| Who it is for | Premenopausal women with acquired, generalized HSDD; not indicated for postmenopausal women or men, nor to enhance sexual performance | — none stated |
| Source | Vyleesi prescribing information, as quoted on the PT-141 compound page | None |
The label's 1.75 mg comes in an autoinjector, so nothing is mixed or drawn up. A research vial is a different product: it is reconstituted with water before anything can be measured, and its milligrams become syringe units only through arithmetic. For reference only, that arithmetic on the label figure: a 10 mg vial with 2 mL of water is 5 mg/mL, or 50 mcg per unit, so 1.75 mg is 35 units (0.35 mL), and the vial holds about 5.7 of that quantity. The tables below include 1.75 mg among their quantities.
The table converts reference quantities to syringe units at the default of 5.0 mg/mL (10 mg of PT-141 in 2 mL), and counts how many draws of each a vial holds. Every row is arithmetic, not a dose: read the units for the amount you already intend to measure.
| Quantity | Draw at 5.0 mg/mL | Volume | Draws from a 5 mg vial | Draws from a 10 mg vial |
|---|---|---|---|---|
| 100 mcg | 2.0 units | 0.02 mL | 50 | 100 |
| 250 mcg | 5.0 units | 0.05 mL | 20 | 40 |
| 500 mcg | 10.0 units | 0.10 mL | 10 | 20 |
| 1 mg | 20.0 units | 0.20 mL | 5 | 10 |
| 1.75 mg | 35.0 units | 0.35 mL | 2.86 | 5.71 |
The same PT-141 quantity lands on a different mark depending on how much water went into the vial. Read down the column for the concentration you actually mixed; a units figure carried across from another column is simply wrong.
| Quantity | At 10 mg/mL (10 mg + 1 mL) | At 5.0 mg/mL (10 mg + 2 mL) | At 2.0 mg/mL (10 mg + 5 mL) |
|---|---|---|---|
| 100 mcg | 1.0 units | 2.0 units | 5.0 units |
| 250 mcg | 2.5 units | 5.0 units | 12.5 units |
| 500 mcg | 5.0 units | 10.0 units | 25.0 units |
| 1 mg | 10.0 units | 20.0 units | 50.0 units |
| 1.75 mg | 17.5 units | 35.0 units | 87.5 units |
Every cell is the same arithmetic: units = (quantity in mg ÷ concentration in mg/mL) × 100 on a U-100 syringe. More water spreads the same mass over more units, which is the fix when a small quantity would otherwise sit at two or three units, where a one-unit misread is a large error.
Each PT-141 vial holds as many draws as its labelled mass divided by the quantity per draw; the water volume changes nothing about it. The grid counts draws, not weeks — the Vyleesi label sets its own limits (as needed, no more than one dose in 24 hours and no more than 8 per month); the grid does not turn them into a schedule.
| Vial size | At 100 mcg | At 250 mcg | At 500 mcg | At 1 mg | At 1.75 mg |
|---|---|---|---|---|---|
| 5 mg | 50 | 20 | 10 | 5 | 2.86 |
| 10 mg | 100 | 40 | 20 | 10 | 5.71 |
The labelled mass is not a guarantee of the mass in your vial: net content is a separate measurement from purity, and certificates on file often measure a few percent above or below the label.
Vyleesi is not reconstituted, and no page on Peptigrity sets a diluent volume for research-grade PT-141, so the volume is a choice. The one decision with real consequences is resolution: at 10 mg/mL (a 10 mg vial with 1 mL) the 1.75 mg label figure is 17.5 units, while at 2 mg/mL (the same vial with 5 mL) it is 87.5 units, where a one-unit misread matters far less. The technique is covered once, elsewhere, as general guidance rather than a PT-141-specific finding: reconstituting peptides step by step and the bacteriostatic water guide.
The calculator assumes the vial holds PT-141. The compound page flags the sharp edge: research-grade PT-141 and Melanotan II differ by about one Dalton (free acid versus amide), so telling them apart takes quality mass-spectrometry data — an HPLC purity number alone cannot do it, and mislabelling between the two occurs in research-grade markets. See Melanotan II and the PT-141 lab tests and identity checks. Receptor pharmacology and the trial programme are in the PT-141 bremelanotide science article.
PT-141 (bremelanotide) is FDA-approved as Vyleesi for hypoactive sexual desire disorder in premenopausal women, and is available by prescription through licensed pharmacies (compound page last updated August 2026). The approval applies to Vyleesi specifically: research-grade PT-141 sold by third-party laboratories for laboratory use is distinct from the FDA-approved prescription product. The label's Limitations of Use state it is not indicated for HSDD in postmenopausal women or in men, nor to enhance sexual performance.
The label's safety record, as the compound page reports it: the most common side effects in the Phase 3 trials were nausea (40%), flushing (20%), injection-site reactions (13%), headache (11%) and vomiting (5%). Blood pressure rises transiently after each dose, which is why Vyleesi is contraindicated in uncontrolled hypertension or known cardiovascular disease, and focal hyperpigmentation was seen in 1% of patients dosing up to 8 times per month, rising to 38% with daily dosing for 8 days.
Independent test records: PT-141 lab tests. Tracked prices, last read 21 September 2026: a median of $4.40 per mg across 74 comparable offers, ranging from $2.00 to $8.00 per mg, in vials from 8 mg to 10 mg — see PT-141 price per milligram. The category page is libido & sexual wellness.
It depends on the concentration. At the page default of 5 mg/mL (a 10 mg vial with 2 mL of water), 1.75 mg is 35 units (0.35 mL) on a U-100 syringe. With 1 mL in the same vial (10 mg/mL) it is 17.5 units; with 5 mL (2 mg/mL) it is 87.5 units. A units figure quoted without a concentration cannot be used.
There isn't one for research-grade PT-141, and Peptigrity does not recommend a dose. The only sourced figure is the Vyleesi prescribing information: 1.75 mg subcutaneously, as needed, at least 45 minutes before anticipated sexual activity, with no more than one dose in 24 hours and no more than 8 doses per month. It applies to the prescription autoinjector for premenopausal women with HSDD; research-grade use is not FDA-approved.
Yes. PT-141 is bremelanotide, which the FDA approved as Vyleesi in 2019. The FDA approval covers the Vyleesi prescription product only; research-grade PT-141 sold for laboratory use is not that product.
Divide the label mass by the quantity: a 10 mg vial holds about 5.7 quantities of 1.75 mg, and a 5 mg vial about 2.9. The water volume changes the units per draw, not the number of draws. The label mass is also not a guarantee of the mass in the vial; net content is a separate measurement.
Only with mass spectrometry. Research-grade PT-141 and Melanotan II differ by about one Dalton (free acid versus amide), so an HPLC purity number alone cannot distinguish them. Look for identity confirmation on the certificate, not just a purity figure.