S107

S107 was developed in the laboratory of Andrew Marks as a tool to test whether stabilizing leaky ryanodine receptors could correct disease. The unifying concept is that under chronic stress, disease, or oxidative and nitrosative modification, RyR channels lose their stabilizing calstabin subunit and become leaky, allowing calcium to escape the sarcoplasmic reticulum and disrupt normal signaling. Rycals such as S107 restore calstabin binding and close the leak.

Across a broad set of models this mechanism has proven remarkably consistent. Leaky RyR2 channels drive atrial fibrillation and ventricular arrhythmias, and S107-type stabilization reduces these events ^[2][4], while RyR leak contributes to myocardial ischemia-reperfusion injury [3-adjacent work]. In skeletal muscle, remodeling of the RyR1 complex causes leaky channels and decreased exercise capacity that Rycal treatment improves ^[3], and RyR1 leak is a therapeutic target in inherited myopathies ^[1]. Strikingly, the same channel biology extends to the brain, where leaky neuronal RyR channels were linked to stress-induced cognitive dysfunction, connecting S107 to research on post-traumatic stress and memory ^[5].

S107 remains an experimental research compound. It has been influential in establishing RyR calcium leak as a druggable mechanism and in guiding later clinical-stage Rycal molecules, but it is not itself an approved drug and has no established human safety data.

S107 is a research compound with no approved human use and no established human safety profile. Preclinical studies report benefit without major reported toxicity at the doses used, but ryanodine receptors are essential to normal heart, muscle, and neuronal function, so the consequences of chronic pharmacological RyR modulation in humans are not defined. It should be treated strictly as an experimental laboratory substance.

S107 was created in the 2000s in Andrew Marks's laboratory at Columbia University as part of the Rycal program investigating ryanodine receptor calcium leak. It became the prototype tool compound for demonstrating that stabilizing leaky RyR channels could improve outcomes in models of heart failure, arrhythmia, muscular dystrophy, muscle fatigue, and later stress-related cognitive dysfunction, informing the development of successor Rycal molecules that advanced toward the clinic.

In cardiac and muscle physiology S107 is a well-regarded proof-of-concept tool that helped establish RyR calcium leak as a legitimate therapeutic target, and it is widely cited in that literature. It has minimal consumer presence and is not sold as a supplement. Its reputation is that of an important mechanistic research compound rather than a finished therapeutic, with clinical translation carried forward by related Rycal molecules.