Comparison
PT-141 vs Semaglutide
Side-by-side of PT-141 and Semaglutide. 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.
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.
Semaglutide
Semaglutide for weight loss: GLP-1 agonist (Ozempic, Wegovy) drives 15-17% mean loss at 2.4 mg/week in STEP trials. Watch lean-mass loss.
Effects at a glance
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
Semaglutide
- •Long-acting GLP-1 receptor agonist with a ~7-day half-life that supports once-weekly subcutaneous dosing
- •STEP trials reported ~15 to 17% mean body-weight loss at 2.4 mg/week over 68 weeks in adults with obesity
- •Lowers HbA1c by ~1.0 to 1.8 percentage points in type 2 diabetes versus placebo
- •SELECT trial showed reduced major cardiovascular events in adults with prior CVD and overweight or obesity
- •Up to 25 to 40% of weight lost can be lean mass; pairing with resistance training and protein intake mitigates this
- •GI effects (nausea, vomiting, constipation) drive most discontinuations and ease with slow titration
Side-by-side
| Attribute | PT-141 | Semaglutide |
|---|---|---|
| Category | peptide | pharmaceutical |
| Also known as | Bremelanotide, Vyleesi | Ozempic, Wegovy, Rybelsus |
| Half-life (hr) ↗ | 2.7 | 168 |
| Typical dose (mg) ↗ | 1.75 | 2.4 |
| Dosing frequency | as needed (max once per 24 hours, max 8 per month) | weekly (SC); daily (oral Rybelsus) |
| Routes | subcutaneous | subcutaneous, oral |
| Onset (hr) | 0.75 | 24 |
| Peak (hr) | 1.5 | 72 |
| Molecular weight | 1025.18 | 4113.58 |
| Molecular formula | C50H68N14O10 | - |
| Mechanism | 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. | Long-acting GLP-1 receptor agonist; potentiates glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and acts on hypothalamic satiety centers. |
| Legal status | 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. | Prescription only (FDA-approved, EMA-approved) |
| WADA status | allowed | allowed |
| DEA / Rx | Rx only (not a controlled substance) for the FDA-approved Vyleesi formulation | Rx only (not a controlled substance); FDA-approved for type 2 diabetes (2017) and chronic weight management (2021) |
| Pregnancy | Not recommended; contraindicated during pregnancy per Vyleesi label | Not recommended; discontinue 2 months before planned pregnancy |
| CAS | 189691-06-3 | 910463-68-2 |
| PubChem CID | 9941379 | 56843331 |
| Wikidata | Q422059 | Q27089394 |
Safety profile
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)
Semaglutide
Common side effects
- nausea
- vomiting
- diarrhea
- constipation
- decreased appetite
- injection-site reactions
- fatigue
Contraindications
- personal or family history of medullary thyroid carcinoma
- multiple endocrine neoplasia type 2
- pregnancy
- history of pancreatitis (use caution)
Interactions
- insulin: additive hypoglycemia risk; insulin dose typically reduced(major)
- sulfonylureas (glipizide, glyburide): hypoglycemia risk, sulfonylurea dose often reduced(major)
- oral medications (general): delayed gastric emptying can alter absorption kinetics(moderate)
- warfarin: monitor INR due to altered absorption(moderate)
Which Should You Take?
Semaglutide comes out ahead for most readers on the criteria we weight: 2 catalogued goals, prescription-only, 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 sexual function, pick PT-141.
- → If your priority is libido, pick PT-141.
- → If your priority is metabolic health and glucose control, pick Semaglutide.
- → If your priority is fat loss, pick Semaglutide.
Edge case: If you cannot self-administer injections, Semaglutide is the only oral option in this pair.
Default choice: Semaglutide. 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 PT-141 and Semaglutide?
PT-141 and Semaglutide differ in category (peptide vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, PT-141 or Semaglutide?
PT-141 half-life is 2.7 hours; Semaglutide half-life is 168 hours.
Can you stack PT-141 with Semaglutide?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
Go deeper