This yellow, oval pill imprinted with 5 6 W is a sertraline (as sertraline hydrochloride) 100 MG Oral Tablet, per the NIH.
Sertraline Hydrochloride is a human prescription drug. The active pharmaceutical ingredient is sertraline hydrochloride and is classified as, "Serotonin Reuptake Inhibitor [EPC], Serotonin Uptake Inhibitors [MoA]."
This pill is made by a total of 3 firms: (1) West-ward Pharmaceutical Corp, (2) PD-Rx Pharmaceuticals, Inc., and (3) Med-Health Pharma, LLC.
There is 1 other yellow pill that with a similar imprint: "5 6 W". They may be a different dosage of the same drug or a different drug entirely.