Source comparison
MK-677 vs. HGH | Comprehensive Comparison
Both hGH and MK-677 have been studied for their effects on serum GH, body composition, and various metabolic parameters in adults. Here, we'll detail where the two compounds align and diverge, focusing on their research applications, safety profiles, and route
This comparison does not assign a generated winner or score.
- Both hGH and MK-677 have been studied for their effects on serum GH, body composition, and various metabolic parameters in adults.
- Here, we'll detail where the two compounds align and diverge, focusing on their research applications, safety profiles, and routes of administration:
- Administration: hGH must be injected due to its protein structure and sensitivity to digestion, whereas MK-677, with over 60% oral bioavailability, can be taken orally. Administering both in the evening aligns with natural GH release and may mitigate MK-677's appetite-increasing effects [2].
- Mechanism of action: hGH therapy raises GH levels even in those with a non-functioning pituitary gland, as it supplies the body with exogenous growth hormone. Conversely, MK-677 enhances GH production only if the pituitary gland remains functional.
- Half-life: MK-677 has a half-life of about 4-6 hours, sufficient to stimulate a prolonged increase in natural GH synthesis. On the other hand, hGH has a half-life of 3-4 hours, and serum GH remains elevated for up to 12 hours after injection. Thus, both compounds are suitable for once-daily administration [2, 11].
- Changes in serum GH levels: hGH results in a dose-dependent rise in serum GH levels, with high doses risking supraphysiological increases and side effects. In contrast, MK-677 stimulates natural GH synthesis that is subject to endogenous hormonal regulation, such as by somatostatin. Research indicates that MK-677 taken at 25mg/daily can lead to a 70% increase in pulsatile GH levels and a 97% increase in 24-hour mean GH levels [12].
- Changes in serum IGF-1 levels: Both hGH therapy and MK-677 can induce an increase in the levels of insulin-like growth factor-1 (IGF-1), which is the main anabolic mediator of GH's effects. According to research, administering MK-677 daily can lead to a 55% increase in IGF-1 levels at 2 weeks and 88% at 4 weeks [12, 13].