MK-677 (Ibutamoren/Nutrobal)

MK-677, also known as Ibutamoren or Nutrobal, is not technically a SARM but shares similar anabolic properties. Studies have shown it targets the ghrelin receptor and triggers a signaling cascade that has the potential to increase growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels. When MK-677 binds to the ghrelin receptor, it appears to mimic the action of ghrelin and activates it, which could lead to an increase in the secretion of GH and IGF-1 from the pituitary gland. GH and IGF-1 are vital anabolic hormones that support muscle growth, bone density, and metabolism while reducing fat. The potential benefits of MK-677 are not limited to anabolic effects, as it may also increase appetite, improve sleep quality and duration, and support the healing of soft tissue injuries. The potential increase in GH levels may also contribute to  neuroprotective and cognitive-enhancing properties.

YK-11 (Alpha Strength)

YK-11 is generally classified as a SARM, although it may also have some steroid-like properties. Some researchers have suggested that YK-11 may be more accurately classified as a "myostatin inhibitor" due to its unique ability to selectively inhibit myostatin, a protein that regulates muscle growth. However, because YK-11 binds to androgen receptors and has androgenic effects, it is still typically classified as a SARM. YK-11 is known for its potential potent muscle-building properties and research suggests it works by inhibiting the action of myostatin, a hormone that limits muscle growth, and increasing the production of follistatin, a protein that promotes muscle hypertrophy. Theoretically, this could lead to increased muscle mass and strength beyond what is achievable with other SARMs. YK-11 may also increase bone density and promote fat loss by activating the protein kinase B signalling pathway and promoting the production of brown adipose tissue. Furthermore, YK-11 may even have the potential to increase endurance and speed up recovery times by increasing the levels of PPARδ and reducing inflammation through COX-2.