Comparison
Epitalon vs PT-141
Side-by-side of Epitalon 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.
Epitalon
Epitalon peptide (Epithalon, tetrapeptide AEDG): telomerase activation, lifespan extension data, anti-aging trials, dosage, half-life, and safety.
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
Epitalon
- •Synthetic tetrapeptide (Ala-Glu-Asp-Gly) developed at the St. Petersburg Institute of Bioregulation
- •Russian clinical literature reports mortality reduction in elderly cohorts and improved melatonin output
- •Reported telomerase activation in human somatic cell culture and lifespan extension in mice and Drosophila
- •Independent Western replication is essentially absent; no FDA-standard RCTs
- •Anecdotal protocols use 5 to 10 mg subcutaneously daily for 10 to 20 day cycles, 2 to 4 times yearly
- •Not currently on the WADA Prohibited List
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 | Epitalon | PT-141 |
|---|---|---|
| Category | peptide | peptide |
| Also known as | Epithalon, Ala-Glu-Asp-Gly, AEDG, Epithalamin (precursor extract) | Bremelanotide, Vyleesi |
| Half-life (hr) ↗ | 0.5 | 2.7 |
| Typical dose (mg) ↗ | 5 | 1.75 |
| Dosing frequency | daily during cycle | as needed (max once per 24 hours, max 8 per month) |
| Routes | subcutaneous, intramuscular, intranasal | subcutaneous |
| Onset (hr) | 24 | 0.75 |
| Peak (hr) | 168 | 1.5 |
| Molecular weight | 390.35 | 1025.18 |
| Molecular formula | C14H22N4O9 | C50H68N14O10 |
| Mechanism | Synthetic tetrapeptide proposed to interact directly with DNA and chromatin to modulate tissue-specific gene expression. Reported effects include telomerase activation, increased melatonin output from pineal cells, and circadian normalization. | 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 | Not FDA approved; registered in Russia under domestic pharmaceutical framework; research-use-only grey market in US/EU | 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 | unknown | allowed |
| DEA / Rx | Not scheduled (research chemical) | Rx only (not a controlled substance) for the FDA-approved Vyleesi formulation |
| Pregnancy | Insufficient data; not recommended | Not recommended; contraindicated during pregnancy per Vyleesi label |
| CAS | 307297-39-8 | 189691-06-3 |
| PubChem CID | 219042 | 9941379 |
| Wikidata | Q5384126 | Q422059 |
Safety profile
Epitalon
Common side effects
- injection-site reactions
- occasional mild headache (rare)
Contraindications
- pregnancy
- lactation
- active malignancy (theoretical telomerase concern)
- concurrent immunosuppression
Interactions
- melatonin: potential additive effect on circadian and pineal output; no controlled data(minor)
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?
PT-141 comes out ahead for most readers on the criteria we weight: 2 catalogued goals, research-only / gray-market sourcing, with a Tier-A outcome catalogued. Epitalon is the right call when one of the conditionals below applies.
- → If your priority is healthspan extension, pick Epitalon.
- → If your priority is sleep onset or sleep quality, pick Epitalon.
- → If your priority is sexual function, pick PT-141.
- → If your priority is libido, pick PT-141.
Edge case: PT-141 is contraindicated in pregnancy; Epitalon is the safer pick if that applies.
Default choice: PT-141. Wider use case, a Tier-A evidence outcome catalogued, and broader goal coverage. Reach for Epitalon 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 Epitalon and PT-141?
Epitalon and PT-141 differ in category (peptide vs peptide), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Epitalon or PT-141?
Epitalon half-life is 0.5 hours; PT-141 half-life is 2.7 hours.
Can you stack Epitalon 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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