PT-141 Nasal Spray vs Troche vs Injection: What’s the Difference?

PT-141 comes in several forms, but only one is FDA-approved

PT-141 is the research name for bremelanotide, a medicine that acts on melanocortin receptors in the brain involved in sexual desire. You may see it sold in four forms:

• Injection (Vyleesi). A 1.75 mg autoinjector pen used under the skin at least 45 minutes before sex. This is the only form the FDA has approved, and only for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD), according to its prescribing information.
• Nasal spray. Compounded by pharmacies; not FDA-approved.
• Troche or lozenge. Dissolved between the cheek and gum or under the tongue. Compounded; not FDA-approved.
• Rapid-dissolve or oral tablet. Sometimes combined with other ingredients. Compounded; not FDA-approved.

The FDA explains that compounded drugs are not FDA-approved, which means it does not review them for safety, effectiveness or manufacturing quality before they are used. That doesn’t mean a compounded product can’t help, but it does mean the evidence behind it is thinner.

What the research says about each form

Injection

Almost all of the strong evidence is for the injection. In two phase 3 trials of 1,267 premenopausal women with HSDD, those using 1.75 mg bremelanotide as needed had small but statistically significant gains in desire and less distress about low desire than those on placebo over 24 weeks. Vyleesi’s label reports that nearly all of the injected dose reaches the bloodstream.

Nasal spray

Bremelanotide was first studied as a nasal spray. In a 2004 study in men, intranasal PT-141 reached peak levels in about 30 minutes, with flushing and nausea the most common side effects. A 2006 crossover study gave 18 premenopausal women with sexual arousal disorder a single 20 mg nasal dose or placebo; more women reported moderate or high desire after bremelanotide, but measured genital blood flow did not change significantly. That was a small, single-dose study, and later development moved to the injection used in the approval trials.

Troches and oral tablets

We could not find published controlled trials of compounded bremelanotide troches or tablets in women. How much reaches the bloodstream from these forms, and how consistent that is from batch to batch, hasn’t been established in the kind of studies the FDA reviews.

Why the doses look so different

If you compare products, the numbers can be confusing. The early nasal studies used 20 mg, while the approved injection is 1.75 mg. That’s because the route matters: an injection under the skin delivers nearly the whole dose, while the early nasal studies used a dose more than ten times larger. Vyleesi’s label notes that the 20 mg nasal dose used in one of its studies produced about 2.5 times the peak blood level of the 1.75 mg injection. A milligram figure on a compounded spray or troche can’t be compared directly with the injection.

Side-by-side comparison

Safety applies to every form

The side effects documented for the injection are the best guide to what any bremelanotide product can do: nausea (40% in the phase 3 trials), flushing, headache, a brief rise in blood pressure after each dose, and darker patches of skin with frequent use. Vyleesi’s label says not to use it more than once in 24 hours or more than 8 times a month, and not to use it with uncontrolled high blood pressure or known heart disease. Our page on Vyleesi side effects covers these in detail, and Vyleesi cost explains what the approved injection costs.

Where Blys fits

Blys is a compounded, rapid-dissolve tablet that combines PT-141 with oxytocin and tadalafil, taken 30 to 60 minutes before intimacy. Like other compounded PT-141 products it is not FDA-approved, and its ingredients have been studied separately rather than together in the phase 3 trials above. Because it contains tadalafil, it must never be used with nitrate medicines. A licensed clinician reviews your health history and medicines and decides whether it is appropriate for you; read more in PT-141 for women.

Questions to ask before you choose a form

• Is the product FDA-approved, or compounded? If compounded, which licensed pharmacy makes it?
• What dose am I getting, and how was it chosen for this route?
• How long before sex should I take it, and how often can I use it?
• Is it safe with my blood pressure, heart history and other medicines?
• What should I do if I get nausea, flushing or darker skin patches?