This pink, oval pill imprinted with M L 13 is a Levothyroxine Sodium 0.2 MG Oral Tablet, per the NIH.
Levothyroxine Sodium is a human prescription drug. The active pharmaceutical ingredient is levothyroxine sodium and is classified as, "l-Thyroxine [EPC], Thyroxine [Chemical/Ingredient]."
This pill is made by a total of 2 firms: (1) Mylan Pharmaceuticals Inc., and (2) Physicians Total Care, Inc.
There is 1 other pink pill that with a similar imprint: "M L 13". They may be a different dosage of the same drug or a different drug entirely.