PT-141
peptideevidence: emerging · v1Description
PT-141 (bremelanotide) is a melanocortin receptor agonist studied in research applications related to neural signaling pathways. Lyophilized powder. Reconstitute with bacteriostatic water for in-vitro research. Store at -20°C. Certificate of Analysis attached to this listing.
Mechanism summary
PT-141 (bremelanotide) is a synthetic cyclic peptide that activates two melanocortin receptors in the brain, MC3R and MC4R, working through the central nervous system rather than by changing blood flow. [Source: Peptide Dosing Protocols]
How it works
PT-141 (bremelanotide) is a synthetic cyclic peptide that activates two melanocortin receptors in the brain, specifically the MC3R and MC4R. This mechanism is central to its function, as it works through the central nervous system rather than altering blood flow, distinguishing it from traditional erectile dysfunction medications like sildenafil or tadalafil. The activation of these receptors is believed to enhance sexual desire and arousal by modulating neurochemical pathways involved in sexual motivation and behavior.
In clinical studies, particularly the Phase 3 RECONNECT trials (Kingsberg 2019), approximately 1,200 premenopausal women self-administered 1.75 mg of subcutaneous bremelanotide on demand for 24 weeks. The trials demonstrated significant improvements in sexual desire and reductions in distress related to low desire, achieving co-primary endpoints at a p-value of 0.001 in the integrated analysis. The pharmacological action of PT-141 is supported by preclinical studies, such as Pfaus 2004, which showed that melanocortin agonism increases sexual solicitation behavior in rats, indicating a consistent central mechanism via the paraventricular nucleus (PVN) MC4R.
It is important to note that while the mechanism of action is well characterized, the evidence supporting the use of PT-141 in populations outside of premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD) is limited. There is no Phase 3 evidence for its use in men, postmenopausal women, or via the intranasal route for any indication, making its use outside the FDA-approved protocol off-label and unsupported by robust clinical data. [Source: Peptide Dosing Protocols]
In plain language
PT-141 works by activating specific receptors in the brain that enhance sexual desire and arousal, rather than affecting blood flow.
Reference details
Route(s)
—
Tags
—
Active
yes
Product details · P41
Price
$42.99
Stock
in stock
Mol. weight
1025.2 g/mol
Formula
C50H68N14O10
Purity
≥ 99%
CAS #
189691-06-3
Amino sequence: Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH (bremelanotide)
COA: View certificate (batch TET-4722-B) →
Teton Labs product catalog · research-use compound data.
💉 Dosing — 2 references (verbatim from source · not a recommendation)
Dose
1.75 mg
Route
subcutaneous or oral
Duration
of action from 3-day dosing.
Source: Peptide Protocol Wiki (peptideprotocolwiki.com) (publication)Source-backedProvider-reviewed
Dose
Standard: 1.75 mg · Low: 7.5 mg · High: 20 mg
Route
Subcutaneous (abdomen or thigh)
Frequency
1 dose per 24 hours
Cycle
8 doses per month
Reconstitution
reconstitution math, route considerations, and side effects for this bremelanotide peptide.
Source: Peptide Dosing Protocols (peptidedosingprotocols.com) (publication)Source-backedProvider-reviewed
Safety, contraindications & monitoring
Contraindications — who should avoid
- nce Skin tanning, sexual function enhancement, and appetite suppression 💉 Dosing Amount Loading: 0.25-0.5 mg daily; Maintenance: 0.5-1.0 mg 1-2 times per week Frequency Daily during loading (1-3 weeks); 1-2 times per week for maintenance Duration Loading: 2-4 weeks; Maintenance: ongoing as desired Step-wise Titration 💊 Administration Route SC Schedule Daily during loading (1-3 weeks); 1-2 times per week for maintenance Timing Evening dosing preferred (nausea is common, sleeping through it reduces discomfort) 📅 Cycle Duration Loading: 2-4 weeks; Maintenance: ongoing as desired Repeatable Yes Loading phase followed by maintenance Preparation & Storage Diluent: Bacteriostatic water ⚗️ Suggested Bloodwork ( 4 tests) CMP with liver enzymes When: Baseline Why: Baseline metabolic function Blood pressure When: Baseline Why: MT-2 can affect blood pressure Blood pressure When: Weekly during loading Why: Monitor cardiovascular effects Blood pressure When: Ongoing Why: Hypertension or hypotension episodes ⚠️ Hypertension or hypotension episodes 💡 Key Considerations → Start with low dose (0.25 mg) and titrate up to assess tolerance → UV exposure enhances tanning effect but is not required → Contraindication: Avoid in melanoma or high melanoma risk; contraindicated in uncontrolled hypertension; use extreme caution with cardiovascular disease Subscribe to unlock this content Get weekly peptide research summaries, new study alerts, and
- Not approved for postmenopausal women, men, or pediatric use.
Safety & side effects
- Most reported side effects are mild and transient.
- Comprehensive human safety data may be limited.
- Consult the detailed side effects profile for full information.
- Not FDA-approved; FDA issued consumer warning (2007) and warning letter to supplier (2009); marketed as unapproved new drug Regulations vary by country and may change.
- Adverse events similar (nausea, autonomic effects); tolerability concerns documented Clinical (tanning origin) Sunless tanning / photoprotection (origin of MT-II trials) Phase I tanning trial in humans (healthy volunteers); pro-ere
- Melanotan-2 remains the more pharmacologically diverse compound with broader melanocortin effects including tanning, but its lack of regulatory approval and wider side effect profile reflect its
- PT-141 represents what happens when a promising lead compound is properly developed through clinical trials, while MT-2 remains in the research domain with significant safety concerns.
- Peptide Protocol Wiki March 30, 2026 BPC-157 Thymosin Alpha-1 AOD-9604 + 16 more Research Review 11 min read Melanotan Tanning Peptides: Risks and Research Evidence Melanotan-1 and Melanotan-2 tanning peptide review — how they work, documented risks including mole changes, side effects, and legal status.
- Peptide Protocol Wiki February 10, 2026 Melanotan-2 Melanotan-1 PT-141 + 1 more Guide 11 min read Peptide Therapy Side Effects: What to Expect by Category Peptide therapy side effects by category: GLP-1 agonists, GH secretagogues, healing peptides, and tanning peptides — when to seek care.
- Peptide Protocol Wiki February 10, 2026 Semaglutide Tirzepatide BPC-157 + 2 more Guide 11 min read Peptides for Sexual Health: PT-141, Kisspeptin, and Beyond Peptides for sexual health — PT-141, kisspeptin, Melanotan-2, and oxytocin — covering mechanisms, clinical evidence, and safety data.
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- Browse all skin peptides → Table of Contents 📌 TL;DR • Potent melanocortin receptor agonist stimulating melanogenesis • Precursor compound to PT-141 (bremelanotide) for sexual dysfunction • Investigated for appetite suppression via MC4R activation • Cyclic structure confers enhanced stability over linear analogs Community-Reported Side Effects Anecdotal ?
- Side effects may include nausea, headache, and flushing.
- Melanotan-2: Tanning and Sexual Health Peptide | Peptide Protocol Wiki Skip to main content 🧬 Peptide Protocol Wiki Peptides Side Effects New Learn Directory Tools Blog News About ⌘K ⌘K 🌱 New to Peptides?
- Covers melanocortin mechanism, Scenesse for EPP, photoprotective tanning, and safety data.
- Long‑term safety, including carcinogenic risk, has not been established.
- Adverse events and harms • In controlled trials: Nausea was frequent (≈38% of injections), with severe nausea in ≈15%; yawning/stretching were common; vomiting was rare; no serious adverse events were recorded during the monitored study periods.
- • Population‑level synthesis: A systematic review of injecting image/performance‑enhancing drug use notes MT‑II harms are documented largely as single cases or small series, including priapism, pigmentary changes/naevi, systemic toxicity, and GI/neurologic symptoms.
- Safety concerns are prominent: high rates of nausea in trials and multiple case reports of serious harms (e.g., priapism, renal infarction), alongside major quality and regulatory issues with illicit products.
- • Lack of long‑term safety: No prospective data on melanoma incidence, cardiovascular/renal outcomes, or other chronic risks; case reports cannot establish incidence or causality.
- • Product and access issues: Most real‑world use involves unregulated, variably composed injectable products; this undermines reproducibility and safety assessment.
- • Safety signals vs.
- uncertain benefit: Reports of serious harms (priapism, rhabdomyolysis/renal injury; possible melanoma association) contrast with limited, short‑term efficacy evidence; professional bodies caution against use.
- Adverse effects are common in trials (notably nausea), and serious harms are reported in case literature.
- On balance, current evidence quality is low, the extent is narrow, and key gaps include long‑term safety and standardized, regulated formulations.
- Clinical case reports also describe dermatologic safety signals, including eruptive nevi and melanoma in situ temporally associated with MT‑II exposure.
- MT‑II’s tanning origins and the emergence of dermatologic safety signals, including reports of melanoma in situ, underscore the need for regulated use and further controlled safety studies.
- Early clinical crossover trials show significant short‑term efficacy in psychogenic and organic ED as measured by RigiScan rigidity thresholds and duration, with predictable, mostly transient adverse effects led by nausea.
- Safety signals and dermatologic outcomes Case reports document temporal associations betwe
- Tanning/photoprotection origin: In a Phase I tanning study, MT‑II increased skin pigmentation and unexpectedly elicited pro‑erectile responses, which catalyzed subsequent ED trials; commonly reported side effects included nausea and penile erections.
- Demonstrates variable potency, measurable impurities, and sterility/label concerns in illicit market—major safety/regulatory issue Harms synthesis (systematic review) Brennan et al., 2017 Systematic revie
- w of injecting IPED use; summarizes case reports/series (Melanotan evidence largely case-based) Varied self-injection exposures N/A (evidence synthesis) Reports of priapism, pigmentation changes (naevi), systemic toxicity, GI/neurologic symptoms; evidence base dominated by case reports/series Highlights paucity of controlled safety data and reliance on case reports for harm signals Evidence Gaps and Limitations # The current evidence base for Melanotan-2 consists primarily of preclinical studies.
- Adverse events mirrored those above, led by nausea and autonomic symptoms.
- There are no robust data on long‑term efficacy or safety, including photoprotection or cancer outcomes.
- What are the side effects of Me
- Reported side effects of Melanotan-2 include nausea, flushing, headache, spontaneous erections, skin hyperpigmentation, transient blood pressure increase.
Monitoring & bloodwork
- CBC at baseline and week 4
- Methods included 6‑hour RigiScan monitoring; no serious AEs were reported in‑trial.
- Key limitations and evidence gaps • Small, short studies using surrogate endpoints: ED trials rely on RigiScan monitoring over 6 hours with small samples; external validity and long‑term benefit are unknown.
Clinical evidence
- The strongest published human evidence is a Phase 2 trial in men with ED at higher per-dose amounts than typical compounded sprays.
- Both trials met their co-primary endpoints of improved sexual desire and reduced distress related to low desire. · Kingsberg 2019
Source-backedProvider-reviewedApproved findings drawn from your sources — decision support, not medical advice.
Provider-only reference. This page does not constitute medical advice, a recommendation, or dosing guidance.