MK-677 vs PT-141
Well Studied vs FDA Approved
monitor Mechanism-based · 51% Both MK-677 and PT-141 can raise blood pressure. Monitor BP regularly and consider adding cardiovascular support (cardarine, telmisartan, or similar).
Molecular Data
MK-677 PT-141
Weight 624.77 Da —
Half-life ~24 hours ~2.7 hours
Type Non-peptide ghrelin receptor agonist Melanocortin receptor agonist
Key Benefits
MK-677
01 97% increase in 24-hour growth hormone secretion
02 40-72% elevation in IGF-1 levels
03 Enhanced sleep quality with improved REM patterns
04 Preferential lean tissue gains of 1.1-2.7kg over 8-12 months
05 15% basal metabolic rate increase within 2 weeks
06 Oral administration (no injections required)
PT-141
01 FDA-approved pharmaceutical route
02 Predictable absorption profile
03 Effective for both male and female sexual dysfunction
04 Works within 45 minutes
05 Effective in PDE5 inhibitor-resistant cases
06 Central mechanism (not dependent on blood flow)
Dosing Protocols
MK-677
Start 12.5mg daily, increase to 25mg based on tolerance / Once daily, preferably at bedtime on empty stomach
PT-141
Women: 1.75mg (FDA-approved); Men: 1-2mg; Start 0.5mg test dose for tolerance / As needed before sexual activity; max 1 dose per 24 hours
Female HSDD (FDA-approved) 1.75mg As needed, max 1 dose/24hr
Male Erectile Dysfunction 1-2mg As needed, 45-60min before activity
Female Arousal Disorder 0.75-1.25mg As needed, max 1 dose/24hr
Low Starting Dose 0.5mg Test dose for tolerance assessment
Side Effects
MK-677
Appetite stimulation (>50% of users)
Water retention (30-40%)
Lethargy (20-30%)
Fasting glucose elevation (5-15mg/dL)
Note on testosterone suppression: at doses up to 20 mg daily, MK-677 is unlikely to cause significant testosterone suppression on its own. Above 20 mg daily, the likelihood of suppression and other side effects (insulin resistance, water retention, lethargy) increases. The case report documenting 85.7% testosterone suppression involved co-administration with LGD-4033, a SARM known to be profoundly suppressive, making the SARM the likely primary driver of that suppression.
PT-141
Nausea (40%)
Flushing (20%)
Headache (11%)
Injection site reactions
Contraindications
Heart disease or congestive heart failure
Diabetes or pre-diabetes
Active cancer
Severe cardiovascular disease
Pregnancy or breastfeeding
Uncontrolled hypertension
Cardiovascular disease
Use of nitrate medications
Pregnancy or breastfeeding
Research Evidence
MK-677 PT-141
Status Well Studied FDA Approved
References 7 studies 4 studies
Latest July 2024 2022
FDA Approved No Yes
This comparison is for educational and research purposes only. Consult a healthcare professional before use.