The methoxy radical (CH₃O) was identified in 2012 by Cernicharo et al. toward B1-b, a low-mass protostar that exhibits complex chemistry. Several rotational lines were observed with the IRAM 30 m radio telescope. No confirming evidence for the presence of CH₃O has been reported to date.

The methoxy radical is related to one of the most common astromolecules, methanol. Removing the H from methanol's O yields CH₃O. Another radical, CH₂OH, can be formed by taking a H off methanol's C instead: it is known as the hydroxymethyl radical, but it has not yet been the subject of a search in the ISM.