Source comparison
Follistatin-344 vs MK-677: Pharmacokinetics Comparison
Route of Administration Intramuscular injection (research protocols use 100–500 mcg per site) Oral administration (10–25mg capsule or liquid suspension) MK-677's oral bioavailability (~62%) makes it significantly more practical for long-term protocols; Follist
This comparison does not assign a generated winner or score.
- Route of Administration
- Intramuscular injection (research protocols use 100–500 mcg per site)
- Oral administration (10–25mg capsule or liquid suspension)
- MK-677's oral bioavailability (~62%) makes it significantly more practical for long-term protocols; Follistatin-344 requires injection expertise and sterile technique
- Half-Life
- Approximately 3–4 hours in circulation (longer tissue retention at injection site)
- 4–6 hours (requiring daily dosing to maintain elevated GH)
- Both compounds require frequent administration. Follistatin's localized effect persists longer at the tissue level despite shorter systemic half-life
- Bioavailability
- Near 100% when administered intramuscularly; negligible oral bioavailability due to protein degradation
- Oral bioavailability 60–62%; not affected by food intake or gastric pH
- Follistatin-344 cannot be taken orally. Researchers attempting oral administration would see complete proteolytic degradation in the stomach
- Systemic vs Local Effect
- Primarily local at injection site; minimal systemic myostatin suppression unless dosed at multiple sites
- Systemic. Affects all tissues expressing GH and IGF-1 receptors uniformly
- This is the critical design distinction: researchers targeting specific muscle groups use Follistatin; those investigating whole-body composition changes use MK-677
- Dose Frequency
- Research protocols range from single-dose (gene therapy vectors) to weekly injections (direct protein)
- Daily dosing required to maintain elevated GH pulse amplitude
- MK-677's daily requirement makes compliance easier to track but introduces consistency variables; Follistatin's less frequent dosing reduces handling but requires more precise per-dose preparation
- Clearance Pathway
- Proteolytic degradation in tissues and serum; renal clearance of fragments
- Hepatic metabolism (CYP3A4); renal excretion of metabolites
- Neither compound produces active metabolites requiring separate tracking. Parent compound activity is the sole research endpoint