Pt-141 Acting as a Melanocortin Antagonist

PT-141 is also sold under the name bremelanotide. This chemical is being developed as a potential means of addressing female sexual dysfunction, reperfusion injuries or hemorrhagic shock. This chemical is used by the body to activate MC1R and melanocortin receptors to control inflammation and limit ischemia. This chemical is a cyclic heapa-peptide which has a lactam analog that includes alpha-melanocyte stimulating hormone or alpha-MSH. This is used to activate receptors in the central nervous system so the chemical can take effect.

This chemical was originally tested for its potential in addressing female sexual dysfunction via intranasal administration. Testing was temporarily suspended for this purpose in 2008 because it was found that applying PT-141 to animals was having negative side effects on blood pressure. The delivery system for this chemical has since been altered,  as a means of limiting this side effect in future test subjects.

Acting as a Melanocortin Antagonist

PT-141 acts as a synthetic peptide analog which can be used in place of an a-MSH receptor.

This reaction includes MC4R and MC3R which are expressed throughout the central nervous system.

Administering PT 141 to rats and primates was seen to cause penile erections. The primate selection did not include human subjects.


Systematically administering this chemical activates the neurons in rat’s bodies that trigger the hypothalamus. This will increase the c-Fos innunoreactivity within the body.

Neurons in similar regions of the central nervous system can increase pseudorabies viruses when they are injected into the corpus cavernosum of rat penises.

Selective Facilitation of Sexual Solicitation

Sexual desire disorders are anticipated to affect 30 percent of women in Europe and North America, but there are currently no pharmacological agents that have been approved to treat this condition.

Effects of chemical models on animal peptides have caused side effects in animal test subjects including lordosis or reflexive sexual behavior.

PT-141, which is designed to bind to melanocortin receptors can selectively stimulate sexual and solicitation behaviors buy pt-141 in female rats. This chemical has been found to create these reactions without altering pacing or lordosis the way similar chemical agents have.

These selective pharmaceutical effects on appetitive sexual behaviors have not been reported with previous experiments using female rats.

These results indicate that the central melanocortin systems are vital to regulating sexual desire in female subjects. As a reaction to this information, it appears that PT 141 may be the first pharmacological agent that has been identified with the potential to address sexual desire issues in females.

Evaluation of Safety

PT 141 was evaluated after subcutaneous adminstiration to animals suffering from erectile dysfunction to compare the reactions to Viagra.

There was an inadequate response to this study with few male test subjects achieving erections that would be suitable for vaginal penetration. This occurred 50 percent of the time while using 100mg applications of Viagra.

Erectile responses were assessed in healthy test subjects by using sexual stimulation. Applications of PT 141 ranged from .3 to 10mg with control test subjects receiving a similar placebo.

Erectile responses to PT 141 were significantly lower than other doses. This notes that the tolerance profile for this chemical is significantly lower than existing pharmaceutical options on the market, with a lower reaction rate from animal bodies.

Researchers may apply PT 141 to test subjects using a variety of methods, but this does mean that you will need to be cautious about which concentrations of this peptide are purchased. Some concentrations are designed to be administered intravenously while others act as a nasal spray. These will offer different concentrations of the peptide which may not be appropriate for different animal subjects, so read the specifications of the product carefully to avoid causing unnecessary side effects.