Comparison
Modafinil vs PT-141
Side-by-side of Modafinil and PT-141. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Modafinil
Modafinil cognitive enhancement profile: wakefulness-promoting agent, 100-200 mg dosing, 12-15 hour half-life, off-label nootropic use, Schedule IV status.
PT-141
PT-141 peptide (bremelanotide, Vyleesi): MC4R agonist for libido and erectile dysfunction. 1.75 mg subcutaneous, 30 to 60 min onset, 2 to 4 h half-life.
Effects at a glance
Modafinil
- •FDA approved in 1998 for narcolepsy, with later additions for shift-work sleep disorder and OSA residual sleepiness
- •Schedule IV controlled substance in the US; prescription-only in EU, UK, Australia
- •Increases wakefulness via weak dopamine reuptake inhibition plus histaminergic, noradrenergic, and orexinergic activation
- •Long half-life of 12 to 15 hours requires morning dosing to avoid sleep disruption
- •Modest cognitive enhancement signal in non-sleep-deprived adults at 100 to 200 mg (Battleday meta-review 2015)
- •Substantial CYP3A4 induction reduces hormonal contraceptive efficacy; barrier methods recommended
PT-141
- •Cyclic 7-amino-acid synthetic peptide and melanocortin receptor agonist (MC4R-preferring)
- •FDA approved in 2019 as Vyleesi for hypoactive sexual desire disorder in pre-menopausal women
- •Acts centrally on hypothalamic sexual-desire circuits rather than peripherally on vasculature
- •On-demand dosing: subcutaneous 1.75 mg approximately 45 minutes before sexual activity
- •Common adverse effects: nausea (~40%), flushing, headache, injection-site reactions, hyperpigmentation
- •Off-label male ED use is documented but not FDA approved; mechanism is distinct from PDE5 inhibitors
Side-by-side
| Attribute | Modafinil | PT-141 |
|---|---|---|
| Category | pharmaceutical | peptide |
| Also known as | Provigil, Modalert, Modvigil, diphenylmethylsulfinyl-acetamide | Bremelanotide, Vyleesi |
| Half-life (hr) ↗ | 13 | 2.7 |
| Typical dose (mg) ↗ | 200 | 1.75 |
| Dosing frequency | daily, morning | as needed (max once per 24 hours, max 8 per month) |
| Routes | oral | subcutaneous |
| Onset (hr) | 1 | 0.75 |
| Peak (hr) | 3 | 1.5 |
| Molecular weight | 273.35 | 1025.18 |
| Molecular formula | C15H15NO2S | C50H68N14O10 |
| Mechanism | Weak dopamine reuptake inhibition plus downstream activation of histaminergic, noradrenergic, and orexinergic wake-promoting systems. | Synthetic agonist of melanocortin receptors with preference for MC4R, expressed in hypothalamic and limbic circuits regulating sexual motivation. Engages central pathways distinct from peripheral PDE5-mediated vasodilation. |
| Legal status | Schedule IV (US); prescription-only globally; not a supplement | Prescription only as Vyleesi; FDA-approved 2019 for HSDD in pre-menopausal women. Compounded versions sold off-label for male sexual function are research-use-only grey market. |
| WADA status | banned | allowed |
| DEA / Rx | Schedule IV | Rx only (not a controlled substance) for the FDA-approved Vyleesi formulation |
| Pregnancy | Not recommended | Not recommended; contraindicated during pregnancy per Vyleesi label |
| CAS | 68693-11-8 | 189691-06-3 |
| PubChem CID | 4236 | 9941379 |
| Wikidata | Q422968 | Q422059 |
Safety profile
Modafinil
Common side effects
- headache
- nausea
- anxiety
- insomnia (with late-day dosing)
- dry mouth
- mild blood pressure elevation
Contraindications
- recent myocardial infarction
- unstable angina
- left ventricular hypertrophy
- significant arrhythmia
- history of Stevens-Johnson syndrome
- psychotic disorders
- pregnancy
- concurrent MAOI use
Interactions
- hormonal contraceptives: CYP3A4 induction reduces contraceptive efficacy; use barrier method(major)
- cyclosporine: reduced cyclosporine levels via CYP3A4 induction(major)
- warfarin: CYP2C9 inhibition raises INR(moderate)
- phenytoin: CYP2C19 inhibition raises phenytoin levels(moderate)
- MAOIs: potential hypertensive reaction(major)
- classical stimulants (amphetamine, methylphenidate): additive cardiovascular and sleep-disruption effects(moderate)
PT-141
Common side effects
- nausea (~40%)
- flushing
- headache
- injection-site reactions
- hyperpigmentation (focal, gums, face, breasts)
- transient blood pressure increase (~6 mmHg systolic)
Contraindications
- uncontrolled hypertension
- established cardiovascular disease
- pregnancy
- naltrexone co-administration (reduces opioid efficacy due to MC receptor crosstalk)
Interactions
- naltrexone (oral): bremelanotide reduces oral naltrexone exposure significantly; avoid co-administration(major)
- antihypertensives: transient BP rise after bremelanotide can offset BP control(moderate)
- PDE5 inhibitors (sildenafil, tadalafil): no documented adverse interaction; mechanisms are non-overlapping(minor)
Which Should You Take?
Modafinil comes out ahead for most readers on the criteria we weight: 3 catalogued goals, controlled substance, oral dosing, with a Tier-A outcome catalogued. PT-141 is the right call when one of the conditionals below applies.
- → If your priority is wakefulness, pick Modafinil.
- → If your priority is focus or working memory, pick Modafinil.
- → If your priority is sexual function, pick PT-141.
- → If your priority is libido, pick PT-141.
Edge case: If you cannot self-administer injections, Modafinil is the only oral option in this pair.
Default choice: Modafinil. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for PT-141 only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Modafinil and PT-141?
Modafinil and PT-141 differ in category (pharmaceutical vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Modafinil or PT-141?
Modafinil half-life is 13 hours; PT-141 half-life is 2.7 hours.
Can you stack Modafinil with PT-141?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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