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PT-141 Nasal Spray: Why Intranasal Bremelanotide Was Dropped in Trials

Bremelanotide was first tested as a nasal spray. Its developer dropped the route over blood pressure rises and uneven absorption, and the approved product is an injection.

Article type
Safety
Sources
7
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6 min
By Leah GarnerPublished

PT-141 nasal spray is not a new idea. Bremelanotide began its life as a spray, and most of the early human studies used one. The route was abandoned before approval, and the reasons bear directly on anyone considering a spray today.

The approved product and its trials are covered in the PT-141 approval and trials, and the approved dose in PT-141 dosage. This page is about the nasal studies. The broader options are on the sexual health goal page.

The nasal studies

The first published human studies gave bremelanotide as a single nasal spray. They enrolled healthy men and men with mild to moderate erectile dysfunction who responded to Viagra [1]. Blood levels rose with the dose, peaked at a median of 0.5 hours and had a half-life of about 1.9 to 2.1 hours. Erections were significantly better than on placebo only at doses above 7 mg.

A crossover study in 19 men with erectile dysfunction paired 7.5 mg by spray with 25 mg of sildenafil [2]. The combination produced a stronger erectile response than sildenafil alone, with no new side effects.

In women, 18 premenopausal women with sexual arousal disorder took a single 20 mg spray or placebo in the clinic [3]. More reported moderate or high desire after the drug. Blood flow measured in the vagina during an erotic video did not change.

Nasal doses in the studies, against the approved injection
StudyRoute and doseWho
Early safety and erection studyNasal, single doses; effect above 7 mgHealthy men and men with ED
With sildenafilNasal 7.5 mg plus sildenafil 25 mg19 men with ED
Arousal disorder pilotNasal 20 mg, single dose18 premenopausal women
Alcohol interaction studyNasal 20 mg on 3 days12 men and 12 women, healthy
Vyleesi labelInjection 1.75 mgPremenopausal women with HSDD
Nasal doses in the studies, against the approved injection The studies cited in this section and the Vyleesi prescribing information.

Why the spray was dropped

The developer explained the decision in its 2009 annual report [5]. It stated that blood pressure rose in some patients using the nasal form, and that this was a significant factor in stopping work on it as a first-line treatment.

The company linked the problem to absorption. It wrote that the blood pressure rises, and the rates of nausea and vomiting, were due at least partly to variable uptake through the nose. It added that plasma levels varied significantly between patients. The same report described a phase 1 trial of the injected form that found no significant difference in mean blood pressure from placebo.

How a 20 mg spray compared with the injection

The Vyleesi label still carries data from the nasal form. It describes a study of a single 20 mg nasal dose taken with alcohol [4]. It states that this dose reaches a peak blood level about 2.5 times that of the approved injection.

The published version of that study enrolled 12 men and 12 women, who took the 20 mg spray on 3 days with or without alcohol [6]. It found no significant interaction with alcohol and no significant drops in blood pressure on standing. It was a safety study in healthy people, not a test of whether the spray works.

The label’s own figures show why exposure is the issue. Injected bremelanotide reaches the blood almost completely, and its overdose section states that nausea, skin darkening and larger blood pressure rises are more likely at higher doses [4].

Where a nasal product stands now

Vyleesi, first approved in 2019, is the only FDA-approved bremelanotide, and it is an injection [4]. Its label gives no nasal dose. Bremelanotide does not appear in any of the three categories of the FDA’s list of bulk substances nominated for compounding, updated May 14, 2026 [7].

A nasal product sold today is not the product the approval covers, and no study has measured how much of it reaches the blood. For how a different compound fares as a spray, see NAD nasal spray. The injected form’s side effects are on bremelanotide side effects.

Frequently asked questions

Is PT-141 nasal spray FDA approved?
No. The only FDA-approved bremelanotide is Vyleesi, an injection under the skin. Its label gives no nasal dose.
Why was PT-141 nasal spray discontinued?
The developer stated in its 2009 annual report that blood pressure rose in some patients using the nasal form, and linked that, and the rates of nausea and vomiting, at least partly to uneven absorption through the nose.
What doses did the PT-141 nasal studies use?
Far higher than the injection: effects on erections appeared above 7 mg in men, a combination study used 7.5 mg with sildenafil, and studies in women and on alcohol used 20 mg. The approved injection is 1.75 mg.
Is a nasal spray stronger than the PT-141 injection?
It depends on the dose and on how much is absorbed. The Vyleesi label states that a 20 mg nasal dose reached a peak blood level about 2.5 times that of the approved injection.

Sources

7 cited
  1. 1Diamond LE, Earle DC, Rosen RC, et al. (2004). Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141, a melanocortin receptor agonist, in healthy males and patients with mild-to-moderate erectile dysfunction International Journal of Impotence Research. PMID 14963471
  2. 2Diamond LE, Earle DC, Garcia WD, Spana C (2005). Co-administration of low doses of intranasal PT-141, a melanocortin receptor agonist, and sildenafil to men with erectile dysfunction results in an enhanced erectile response Urology. PMID 15833522
  3. 3Diamond LE, Earle DC, Heiman JR, et al. (2006). An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist Journal of Sexual Medicine. PMID 16839319
  4. 4Cosette Pharmaceuticals, Inc. (2024). VYLEESI (bremelanotide injection), for subcutaneous use: prescribing information (revised 03/2024) DailyMed, U.S. National Library of Medicine. Source
  5. 5Palatin Technologies, Inc. (2009). Annual Report on Form 10-K for the fiscal year ended June 30, 2009 U.S. Securities and Exchange Commission, EDGAR. Source
  6. 6Clayton AH, Lucas J, DeRogatis LR, Jordan R (2017). Phase I Randomized Placebo-controlled, Double-blind Study of the Safety and Tolerability of Bremelanotide Coadministered With Ethanol in Healthy Male and Female Participants Clinical Therapeutics. PMID 28189361
  7. 7U.S. Food and Drug Administration (2026). Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the FD&C Act (updated May 14, 2026) FDA. Source

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