Description
PT-141, also known as bremelanotide, is a synthetic cyclic heptapeptide, a ring shaped chain of seven amino acids. It belongs to the melanocortin peptide family and was derived from the earlier research compound Melanotan II through targeted structural modification. Its lactam bridge, a cyclic bond formed between amino acid side chains, constrains the molecule into a ring shape, a structural feature shared by several melanocortin peptides.
PT-141 has an unusually well documented development history for a research peptide. Palatin Technologies licensed the compound and refined it into what became bremelanotide, initially developing it as an intranasal spray before shifting to a subcutaneous formulation. In June 2019, the FDA approved bremelanotide under the brand name Vyleesi for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women, based on two Phase 3 clinical trials known as RECONNECT. This makes bremelanotide one of the few peptides in this category with full FDA approval for a specific clinical indication, which provides an unusually deep body of published pharmacological and safety data to draw on for research purposes.
Mechanistically, PT-141 acts as an agonist at melanocortin receptors, primarily MC3R and MC4R, which are expressed in the hypothalamus and limbic system. This distinguishes it from other approaches to sexual dysfunction that work on peripheral blood flow, since PT-141’s activity is centered on receptor signaling in the brain. The compound is supplied as a white to off-white lyophilized powder that dissolves readily in water. This product is strictly for research purposes only and is not approved for human or animal use in this form.
PubChem Reference: View compound profile on NIH PubChem
Key Characteristics
MOLECULAR PROFILE
Formula C50H68N14O10, Weight 1025.2 g/mol, CAS 189691-06-3, Also Known As: Bremelanotide
PHYSICAL PROPERTIES
Form: white to off-white lyophilized powder. Solubility: readily dissolves in water. Storage: keep refrigerated 36 to 46°F (2 to 8°C). Reconstitution: mix with bacteriostatic water.
PT-141 in Published Research
Because bremelanotide is an FDA approved medication under the name Vyleesi, more pharmacological and clinical data exists for PT-141 than for most research peptides. Foundational human pharmacology work published by Wessells and colleagues documented that melanocortin receptor agonism produced measurable physiological responses through a central nervous system mechanism, distinct from the peripheral vascular pathway used by PDE5 inhibitors such as sildenafil. Later Phase 3 trials evaluated bremelanotide specifically for HSDD and formed the basis of its 2019 approval.
Preclinical research using MC4R knockout mouse models has helped establish the specific receptor pathways involved in melanocortin regulated behavior, providing a mechanistic foundation for how PT-141 is believed to work. Researchers studying the melanocortin system have also used PT-141 and related analogs to investigate receptor selectivity, since earlier compounds like Melanotan II activate a broader range of melanocortin receptors and carry different, non-overlapping effects such as changes in skin pigmentation.
Frequently Asked Questions :
What is PT-141 peptide used for in research?
PT-141 (bremelanotide) is studied for its activity at melanocortin receptors, particularly MC3R and MC4R, which are involved in centrally mediated sexual arousal pathways. As the FDA approved medication Vyleesi, it is also a reference compound researchers use to study melanocortin receptor selectivity compared to earlier, broader spectrum compounds like Melanotan II.
What is the FDA approved dose of bremelanotide (Vyleesi)?
The FDA approved Vyleesi formulation is a 1.75 milligram subcutaneous injection, self administered using an autoinjector. This figure comes from the approved drug label and Phase 3 RECONNECT trial data. It reflects the finished pharmaceutical product, not a dosing instruction for a research chemical, and Peptides Vital sells PT-141 strictly for laboratory research.
What side effects were reported in PT-141 clinical trials?
Published Phase 3 data on bremelanotide reported transient increases in blood pressure as a notable finding, along with nausea as one of the more common reported effects. These outcomes come from controlled clinical trials of the approved pharmaceutical product and are shared here for research and educational context.
How is PT-141 different from Melanotan II?
PT-141 was derived from Melanotan II through structural changes that narrow its receptor activity toward MC3R and MC4R, reducing the pigmentation related MC1R activity that is prominent with Melanotan II. This makes PT-141 more selective for the receptor pathways involved in sexual arousal research, while Melanotan II is studied more broadly across the melanocortin receptor family.
Where can I buy PT-141 peptide for research?
Peptides Vital supplies PT-141 as a 10mg kit, verified through HPLC and mass spectrometry testing with a certificate of analysis available on request. It is sold strictly for laboratory and scientific research use.
Carter David –
Third time ordering PT-141 from here. Excellent lyophilized powder, no clumping, and reconstitutes perfectly. Customer service responded quickly to my shipping question too
Linda skyrock –
Fast turnaround and secure packaging. PT-141 works as expected in our in vivo models. No degradation or potency loss compared to other suppliers. Will be a repeat customer for sure
Whitmore –
I’ve tested multiple batches now great solubility and stability. PeptidesVital offers fair pricing and genuine products. The free shipping over $200 is a huge bonus for labs ordering in bulk
Emily Rodriguez –
Finally found a reliable source for PT-141. The international shipping was seamless, and the product matches the COA they provide. Very happy with the consistency
Sarah Jenkins –
PeptidesVital never disappoints. The PT-141 purity is top-notch, and delivery to the US was surprisingly quick. My research data has been very promising. Highly recommend
Michael Thompson –
Consistent quality and fast shipping. PT-141 arrived well-packaged and exactly as described. Been using it in my research protocols with great results. Will order again.