Side-by-side · Research reference
PT-141vsTesofensine
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
AFDA-ApprovedReviewed13/41 cited
BPhase 3Draft10/40 cited
PT-141
MC4R Agonist · FDA-Approved (HSDD)
SQ · Abdomen / thigh · ≥45 min before sex
Tesofensine
SNDRI · Phase 3 obesity candidate
Oral · Once daily morning
01Mechanism of Action
Parameter
PT-141
Tesofensine
Primary target
Melanocortin-4 receptor (MC4R) in hypothalamusSimerly 2023VYLEESI (bremelanotide injecti 2019
Serotonin / norepinephrine / dopamine transporters (SERT / NET / DAT)Astrup 2008
Pathway
MC4R agonism in paraventricular nucleus → autonomic + neuroendocrine sexual arousal pathwaysSimerly 2023
Triple monoamine reuptake inhibition → ↑synaptic 5-HT, NE, DA → appetite suppression + thermogenesisAstrup 2008
Downstream effect
Increased sexual desire and arousal; central rather than peripheral mechanismClayton 2015
Strong appetite suppression, mild thermogenic effect, weight lossAstrup 2008
Feedback intact?
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Origin
Cyclic 7-AA peptide derived from α-MSH (agonist Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-OH cyclic)VYLEESI (bremelanotide injecti 2019
Small molecule developed by NeuroSearch (Denmark) for CNS indications, repurposed for obesityAstrup 2008
Antibody development
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02Dosage Protocols
Parameter
PT-141
Tesofensine
Standard dose
1.75 mg SQVYLEESI (bremelanotide injecti 2019
Single dose ≥45 min before anticipated sexual activity. Max 1 dose / 24 hr.
0.25–0.5 mg / dayAstrup 2008
Frequency
PRN, max 8 doses / month
Once daily, morning
Lower / starter dose
1 mg (off-label)
0.125 mg / day
Evidence basis
FDA-approved (HSDD pre-menopausal women)VYLEESI (bremelanotide injecti 2019Clayton 2015
Phase 2b + ongoing Phase 3Astrup 2008
Duration
PRN; reassess if no benefit after 8 doses
24 weeks per studied cycle
Reconstitution
Pre-filled commercial pen (Vyleesi). Research vial: bacteriostatic water.
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Timing
≥45 min before sexual activity
Morning to avoid sleep disruption
Form
—
Oral capsule
04Side Effects & Safety
Parameter
PT-141
Tesofensine
Flushing
Common, transient
—
Injection site reaction
Erythema, mild pain
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Headache
Common
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Hyperpigmentation (focal)
Rare focal skin darkening; reversible after discontinuationVYLEESI (bremelanotide injecti 2019
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Hypertension (transient)
Mean ↑6 mmHg systolic peaking ~4 h post-dose; resolves within 12 hVYLEESI (bremelanotide injecti 2019
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Pregnancy / OB
Contraindicated
Contraindicated
Cardiovascular disease
Use caution; transient BP rise
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Insomnia
—
Dose-related; mitigate with morning timing
Dry mouth
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Common
Mood changes
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Anxiety / agitation possible
Cardiovascular events
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Phase 3 trial monitoring; not yet FDA-cleared
Absolute Contraindications
PT-141
- ·Uncontrolled hypertension
- ·Known cardiovascular disease (caution)
- ·Pregnancy
Tesofensine
- ·Pregnancy / breastfeeding
- ·Severe cardiovascular disease
- ·Concurrent MAOI use
Relative Contraindications
PT-141
- ·Pre-existing hyperpigmentation disorders
- ·MC4R-pathway-dependent psychiatric conditions
Tesofensine
- ·Hypertension
- ·Anxiety disorder
- ·Insomnia
05Administration Protocol
Parameter
PT-141
Tesofensine
1. Reconstitution
Vyleesi: pre-filled auto-injector. Research vial: 2 mL bacteriostatic water per 10 mg → 5 mg/mL.
Oral capsule (investigational; not commercial).
2. Injection site
SQ — abdomen or thigh.
Swallow whole with water, morning only.
3. Timing
≥45 min before sexual activity for peak effect. Effect persists ~6–8 h.
Morning to mitigate insomnia. Do not dose evening.
4. Storage
Vyleesi: room temp ≤30 °C. Research vial: refrigerate after reconstitution.
Room temp ≤25 °C, dry place.
5. Needle
Auto-injector (Vyleesi) or 29–31G, 4–8 mm insulin syringe.
Monitor BP + HR + mood. Avoid stimulants + MAOIs.