GLPG-0492

GLPG-0492, also identified by its chemical name as a 4-(hydroxymethyl)diarylhydantoin, is a non-steroidal small molecule belonging to the class of selective androgen receptor modulators, or SARMs ^[1][4]. SARMs are compounds designed to bind the androgen receptor, the same protein activated by testosterone, but to do so in a tissue-selective way, with the goal of reproducing the muscle- and bone-building effects of androgens while minimizing unwanted actions on tissues such as the prostate ^[4]. GLPG-0492 was developed by the company Galapagos as a candidate for musculoskeletal disorders.

The compound emerged from a medicinal-chemistry program exploring hydantoin-based androgen receptor ligands ^[1]. Chemists refined a diarylhydantoin scaffold to obtain a potent partial agonist of the human androgen receptor, and in a standard rodent model using orchidectomized (castrated) rats the molecule stimulated muscle growth in a manner strongly dissociated from its effect on the prostate after oral dosing ^[1]. These properties, together with favorable pharmacokinetics, led to its selection for further development and its entry into phase I clinical trials ^[1].

Much of the published research on GLPG-0492 comes from animal models of muscle loss ^[2][3]. In the exercised mdx mouse, a model of Duchenne muscular dystrophy, the compound increased strength and preserved running performance and diaphragm function while reducing markers of fibrosis, with effects broadly comparable to the steroids methylprednisolone and nandrolone but without their full androgenic load ^[2]. In a separate mouse model of muscle atrophy caused by hindlimb immobilization, GLPG-0492 partially prevented muscle loss and was reported to be as effective as testosterone propionate at reducing atrophy while sparing reproductive tissues ^[3]. These findings supported interest in the molecule for conditions such as sarcopenia, cachexia, and disuse atrophy ^[2][3].

Despite promising preclinical data, GLPG-0492 has not become an approved drug and remains an investigational compound. As a selective androgen receptor modulator it sits within a broader class that has been widely studied but that, as of the mid-2020s, had yielded no agent approved for muscle-wasting indications ^[4]. Like other androgen receptor ligands, GLPG-0492 would be expected to influence the body's own hormonal feedback, and its long-term safety in humans has not been established. It is not a licensed medicine and is sometimes encountered only as a research chemical.

There is no meaningful human safety data. Expected class risks include testosterone suppression, cholesterol changes, and possible liver strain with oral use. Since it is only available through research channels, quality and dosing are unreliable.