HD Labs OstarineHD LABS SARMS OSTARINE(MK 2866)12. 5MG TAB=50TABS. MK 2866 Builds Muscle And Burns Fat With multiple published human trials under its belt, MK 2866 (also called ostarine) is one of the best studied SARMs. Those studies found powerful results, too. Ostarine shows no meaningful side effects and is very effective at building muscle. Elderly men and women who took modest doses of ostarine for 12 weeks grew 3 pounds of muscle and lost a pound of fat, with