Cardarine (GW-501516) is grouped in the category of SARMs, however in structure and definition, it is a PPAR modulator.
Ibutamoren (MK-677) is a chemical that has the characteristics of human growth hormone (HGH). It is an orally active growth hormone secretagogue. A secretagogue causes substances to be secreted.
Ligandrol (LGD-4033) is categorized as a SARM. LGD has the capability to bind to the AR (androgen receptor) with an extremely high affinity. LGD is generally classified as an AR ligand that is tissue selective.