Titus Thorne

Last Updated August 17, 2022

Titus Thorne

 August 17, 2022

Researchers interested in experimenting with PT-141 may be curious about how this research chemical has been dosed in past studies. This PT-141 dosage guide aims to answer that very question by summarizing the available research in one coherent, easy-to-read document.

This PT-141 dosage guide will outline what bremelanotide is, the main benefits it offers, and how it has been dosed in past clinical studies and trials. The various doses at which this chemical has been administered to test subjects will be discussed, as will its documented side effects and overall safety profile.

Qualified researchers looking to experiment with PT-141 can find full details of where this peptide can be purchased online at the end of this guide.

Let’s get started!

Buy PT-141 from the #1 online Peptides vendor in the world...

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What is PT-141?

PT-141 is the chemical name for bremelanotide, a melanocortin receptor agonist that was initially developed by Palatin Technologies and released under the brand name “Vyleesi”. Its manufacture was subsequently out-licensed to AMAG Pharmaceuticals Inc. [2].

In 2019, PT-141 was approved by the US Food and Drug Administration for the treatment of premenopausal women with hypoactive sexual desire disorder (HSDD) [1]. In the US, bremelanotide is available as a prescription medicine to patients who have received an HSDD diagnosis. It can be self-administered subcutaneously on demand by patients in their homes [3].

PT-141 can be purchased by researchers as a reference material for the purpose of conducting experiments. Below, the top benefits and uses of this research chemical will be summarized.


PT-141 dosage 2


PT-141 Benefits and Uses | Our Experience

In the US, PT-141 is an FDA-approved medicine that is used to treat premenopausal women who have been diagnosed with HSDD.

Clinical trials involving premenopausal women have shown that PT-141 can:

  • Increase sexual desire [2]
  • Stimulate the release of dopamine [4]
  • Increase the frequency of “satisfying sexual events” [5]
  • Lower intercourse-related distress [6]

It should be noted that these benefits apply solely to premenopausal women with HSDD and do not apply to postmenopausal women (with or without HSDD) or men. Furthermore, PT-141 is not indicated to enhance sexual performance [7].

While PT-141 has not received FDA approval as a treatment for erectile dysfunction (ED), there is some evidence that it may be beneficial for men suffering from this condition.

A 2004 study found that PT-141 prompted a “statistically significant erectile response” when administered to male test subjects who had reported an insufficient response to 100 mg of sildenafil (Viagra) [8].

A later study found that PT-141 produced a “positive clinical result” in 33.5% of men who took it intranasally prior to intercourse [9].

These findings suggest that PT-141 may offer potential as a complementary ED therapy alongside other established treatment options such as Viagra.

Having reviewed the main benefits offered by PT-141, we’ll now briefly consider its known side effects.


PT-141 Side Effects

PT-141 has been extensively researched and found to be safe and well-tolerated. The most common adverse reactions (incidence > 4%) are [7]:

  • Nausea
  • Flushing
  • Injection site reactions
  • Headaches
  • Vomiting

Phase 2 and 3 clinical trials involving bremelanotide (Vyleesi) found that adverse events occurred at the following rates [2,10]:

  • Headaches (11-12%)
  • Facial flushing (20.4-20.6%)
  • Nausea (39.9-40.4%)

Serious adverse reactions were reported in 1.1% of PT-141-treated patients and 0.5% of placebo-treated patients, and 18% of the patients who experienced a serious adverse reaction decided to discontinue the study. The most common reasons for discontinuation were [7]:

  • Nausea (8%)
  • Headache (2%)
  • Vomiting (1%)
  • Flushing (1%)
  • Injection site reactions (1%)
  • Flu-like symptoms (<1%)
  • Increased blood pressure (<1%)

Researchers concluded that PT-141 was safe when administered at 1.75 mg per day, up to a maximum of 8 times per month [11]. However, in very rare cases, PT-141 may cause elevated serum enzyme levels, or liver injury [12].

“Vyleesi” (bremelanotide injections) should not be used by patients with uncontrolled hypertension or known cardiovascular disease and comes with a number of warnings and precautions. Vyleesi may cause [7].

  • A transient increase in blood pressure and decrease in heart rate (up to 12 hours)
  • Focal hyperpigmentation (<1% of patients)
  • Nausea (40% of patients who received up to 8 monthly doses)
  • Slowed gastric emptying and impact absorption of concomitantly administered oral medications
  • Decreased systemic exposure of orally administered naltrexone

Furthermore, PT-141 should not be used by patients where pregnancy is suspected.

In studies involving male patients, the small sample sizes and short duration of the experiments make it difficult to draw any meaningful conclusions about PT-141’s long-term safety in men. While researchers have noted that PT-141 was “safe” [8, 9], this chemical needs to be tested in a well-designed long-term clinical trial before drawing any conclusions regarding its safety [13].

Having reviewed PT-141’s main side effects, it’s time to focus on the main topic in this guide; how PT-141 has been administered to test subjects in past studies and clinical trials.


PT-141 dosage 3


PT-141 Dosage Guide

Researchers curious about how PT-141 has been dosed in past studies and trials may consult the following literature for reference.

What Is the Recommended Dosage of PT-141?

When sold as a reference material, PT-141 has no safe or recommended dosage. However, when purchased as bremelanotide (Vyleesi), the recommended dosage for premenopausal patients with HSDD is “1.75 mg administered subcutaneously in the abdomen or thigh, as needed, at least 45 minutes before any anticipated sexual activity” [7]. Vyleesi injections typically comprise 1.75 mg bremelanotide and 0.3 mL solution.

How Is PT-141 Administered?

Again, PT-141 cannot be administered to test subjects when purchased as a research chemical, but bremelanotide (Vyleesi) is self-administered by patients via a prefilled autoinjector pen. This lets the patients visually inspect the drug for any discoloration or particulate matter prior to administration. Patients are advised to discard the drug if discoloration, a cloudy appearance, or visible particles are noticed.

When Should PT-141 Be Administered?

If purchased as a research chemical, Vyleesi should not be administered. Bremelanotide (Vyleesi) is typically self-administered by patients “at least 45 minutes before anticipated sexual activity”. The optimal window for bremelanotide “has not yet been fully characterized” [7]. Therefore patients may decide the optimal time based on their experience and whether they experience any adverse reactions such as nausea. The duration of efficacy after each dose is currently unknown.

How Often Can PT-141 Be Administered?

When administered to treat HSDD, bremelanotide (Vyleesi) should be administered no more than once within 24 hours, and no more than 8 times per month, as this “may increase the risk of additive effects on blood pressure” [7].

Now that we’ve explored how PT-141 may be dosed, we can look at how this research chemical may be microdosed.


Microdosing PT-141

Data from phase 2 and 3 clinical trials does indicate the efficacy of PT-141 (bremelanotide) when administered in smaller, or “micro” doses.

In the aforementioned 2016 trial, female patients were randomized to receive either a placebo or a dose of bremelanotide in one of three doses:

  • 0.75 mg
  • 1.25 mg
  • 1.75 mg

Data from this study showed that 0.75 mg doses produced a “statistically insignificant” response in participants’ Female Sexual Function Index-desire domain score, but both doses over 1 mg – 1.25 mg and 1.75 mg – produced an increase in sexual satisfaction, by +0.7 and +3.6 respectively [5].

While bremelanotide is not indicated to treat postmenopausal women or men, studies involving male patients have investigated PT-141 at a number of different microdoses. The aforementioned 2004 study administered PT-141 at doses ranging from “0.3 to 10 gm” and found that “statistically significant” erectile responses occurred only “at doses greater than 1.0 mg” [8].

Having looked at the efficacy of microdosing PT-141, we can turn our attention to the best online sources serving peptide researchers.


PT-141 dosage 4


Where To Buy PT-141 Online? | 2022 Guide

PT-141 is widely available online as a research chemical, but researchers may struggle to find a reliable vendor that can supply research-grade PT-141. With so many vendors to choose from, deciding where to place an order is far from easy.

To assist qualified researchers, our team made a series of test orders from the top online vendors and ranked them according to the quality of the PT-141 they supplied, their prices, customer service, and the timeliness of their shipping.

The top vendor?

Peptide Sciences. This vendor outshone the competition in all areas and is our top pick for a reliable, trustworthy PT-141 vendor.

Here are a few specific reasons why Peptide Sciences is our No. 1 recommended peptide supplier for researchers looking for top-quality PT-141:

  • Independent Testing: Our team was highly impressed by Peptide Sciences’ dedication to supplying 99% pure, research-grade PT-141. They have every batch of PT-141 thoroughly tested by an independent lab and post the results on their website. This helps researchers verify the quality of the PT-141 before placing an order.
  • Generous Discounts: Peptide Sciences price their PT-141 at just $47.5 for a 10mg vial, which in itself is highly reasonable. However, they also offer a further 14% discount to researchers who place a bulk order (more than 10 vials). This helps lower the cost of running a long-term experiment or clinical trial.
  • Informative, Secure Website: Peptide Sciences’ website is packed full of top-quality information and is highly secure. It features the latest SSL encryption and protects all customers’ data. Researchers can order in confidence when they shop here.
  • Friendly Customer Support: After placing a test order, our team received high-quality support from Peptide Sciences’ customer support team. They kept us informed about the progress of our order and helped us track our shipment until it reached us.
  • Fast, Reliable Shipping: We were impressed by Peptide Sciences’ shipping policy; orders to the U.S. over $100 ship free, and worldwide orders cost just $15. Researchers will also receive a complimentary 30 mL vial of bacteriostatic water when they order more than $300 worth of peptides.

In summary, Peptide Sciences is by far the most attractive vendor for researchers looking to buy PT-141 online in bulk. They offer the highest quality peptides at reasonable prices and offer reliable worldwide shipping.

Buy PT-141 from the #1 online Peptides vendor in the world...


PT-141 Dosage | The Verdict?

Researchers interested in PT-141 dosage will be pleased to know that this well-researched peptide has been dosed at various amounts in past studies with a low incidence of side effects or adverse effects. While doses of 1.75 mg are common for premenopausal women with HSDD, data from clinical trials show that PT-141 is well-tolerated at larger doses with little risk of causing serious adverse events.

Researchers planning to experiment with, or run a clinical trial with, PT-141 in the near future are advised to consider Peptide Science for a reliable, world-class vendor who has the capacity to meet their needs.


References

  1. Dhillon S, Keam SJ. Bremelanotide: First Approval. Drugs. 2019 Sep;79(14):1599-1606. doi: 10.1007/s40265-019-01187-w. PMID: 31429064. 
  2. Mayer D, Lynch SE. Bremelanotide: New Drug Approved for Treating Hypoactive Sexual Desire Disorder. Ann Pharmacother. 2020 Jul;54(7):684-690. doi: 10.1177/1060028019899152. Epub 2020 Jan 1. PMID: 31893927.
  3. Bremelanotide (Vyleesi) for hypoactive sexual desire disorder. Med Lett Drugs Ther. 2019 Jul 29;61(1577):114-116. PMID: 31381550.
  4. Pfaus JG, Sadiq A, Spana C, Clayton AH. The neurobiology of bremelanotide for the treatment of hypoactive sexual desire disorder in premenopausal women. CNS Spectr. 2021 Jan 18:1-9. doi: 10.1017/S109285292100002X. Epub ahead of print. PMID: 33455598.
  5. Clayton, A. H., Althof, S. E., Kingsberg, S., DeRogatis, L. R., Kroll, R., Goldstein, I., Kaminetsky, J., Spana, C., Lucas, J., Jordan, R., & Portman, D. J. (2016). Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial. Women's health (London, England), 12(3), 325–337. https://doi.org/10.2217/whe-2016-0018 
  6. Kingsberg SA, Clayton AH, Portman D, Williams LA, Krop J, Jordan R, Lucas J, Simon JA. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstet Gynecol. 2019 Nov;134(5):899-908. doi: 10.1097/AOG.0000000000003500. PMID: 31599840; PMCID: PMC6819021. 
  7. (2021). Retrieved 10 October 2021, from https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/210557s000lbl.pdf 
  8. Rosen, R. C., Diamond, L. E., Earle, D. C., Shadiack, A. M., & Molinoff, P. B. (2004). Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141, a melanocortin receptor agonist, in healthy male subjects and in patients with an inadequate response to Viagra. International journal of impotence research, 16(2), 135–142. https://doi.org/10.1038/sj.ijir.3901200 
  9. Safarinejad, M. R., & Hosseini, S. Y. (2008). Salvage of sildenafil failures with bremelanotide: a randomized, double-blind, placebo controlled study. The Journal of urology, 179(3), 1066–1071. https://doi.org/10.1016/j.juro.2007.10.063
  10. Simon JA, Kingsberg SA, Portman D, Williams LA, Krop J, Jordan R, Lucas J, Clayton AH. Long-Term Safety and Efficacy of Bremelanotide for Hypoactive Sexual Desire Disorder. Obstet Gynecol. 2019 Nov;134(5):909-917. doi: 10.1097/AOG.0000000000003514. PMID: 31599847; PMCID: PMC6819023. 
  11. Althof S, Derogatis LR, Greenberg S, Clayton AH, Jordan R, Lucas J, Spana C. Responder Analyses from a Phase 2b Dose-Ranging Study of Bremelanotide. J Sex Med. 2019 Aug;16(8):1226-1235. doi: 10.1016/j.jsxm.2019.05.012. Epub 2019 Jul 2. PMID: 31277966. 
  12. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; 2012–. Bremelanotide. 2021 Aug 20. PMID: 34436837. 
  13. Kim S, Cho MC, Cho SY, Chung H, Rajasekaran MR. Novel Emerging Therapies for Erectile Dysfunction. World J Mens Health. 2021 Jan;39(1):48-64. doi: 10.5534/wjmh.200007. Epub 2020 Mar 16. PMID: 32202086; PMCID: PMC7752520.

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