MK-677, also known as Ibutamoren, is a growth hormone secretagogue that is highly popular among athletes and bodybuilders. It is one of those compounds that is often referred to as a SARM, while it actually isn’t a Selective Androgen Receptor Modulator at all.
WHAT IS MK 677?

Ibutamoren is actually a selective agonist of the growth hormone secretagogue. It is an orally active compound that stimulates the secretion of growth hormone (GH) and insulin-like growth factor 1 (IGF-1).
Other growth hormone secretagogues are mostly peptides, such as GHRP-2, GHRP-6, Hexarelin, and others. Most of these substances increase cortisol levels. The same is not true for MK 677, which is one of the reasons that make this a unique compound.
MK-677 results
Increase lean muscle mass
Ibutamoren increases GH and IGF-1 secretion. Both hormones are well known for their anabolic effects. Therefore MK-677 can increase lean muscle mass. At the same time, it can help to maintain muscle waste. It can be beneficial in the treatment of catabolic conditions.
INCREASE BONE DENSITY
Another benefit associated with increased growth hormone and IGF-1 levels is the possibility to increase bone density. The loss of bone mass is a common issue at a later age in life or as a result of many medical conditions. MK-677 has the potential to drastically decrease bone loss.
IBUTAMOREN IMPROVES SLEEP QUALITY
Growth hormone plays an important role in the quality of sleep. MK-677 Ibutamoren improves sleep quality, especially REM sleep when most recovery takes place. This is reported in numerous scientific studies but is also reported by many users.
MK-677 FOR FASTER Recovery
An increase in growth hormone levels has many positive effects. For instance, it provides a faster recovery. Tissue regeneration improves, resulting in better healing of tendons as well as skin and nails.
POSSIBLE NOOTROPIC EFFECTS
Since MK-677 shares a lot of similar qualities to Ghrelin. We known that ghrelin Is has positive effects on cognitive functions. Because MK 677 binds to the same receptors as ghrelin, it is likely to have similair effects.
SIDE EFFECTS OF MK-677 IBUTAMOREN
The most common side effects associated with the use of MK-677 are:
- An increase in appetite, especially during the first weeks
- Mild lower extremity edema during the first weeks.
- Muscle pain during the initial few days.
Because Ibutamoren increases IGF-1 (Insuline-like growth factor 1), it can also increase blood sugar, which is a risk for people with diabetes or high insulin sensitivity.
Stacking Ibutamoren
Stacking Ibutamoren is a common practice among bodybuildders. It can be combined with androgenic anabolic steroids or with other SARMs. When combined with substances that target the androgen receptors, the anabolic effects of MK677 are increased.
MK-677 questions
During clinical trials MK-677 was well tolerated by the subjects. No serious adverse effects where observed in any of the patients.
There are no studies on the long-term side effects of MK-677 have been conducted.
Ibutamoren does not suppress testosterone levels, which means that a PCT is not needed.
Yes, Ibutamoren is completely legal. More info about the legal status of SARMs can be found in our blog.