The 436 pill most commonly refers to prescription Naproxen 500 mg, manufactured by ScieGen Pharmaceuticals, Inc. (imprinted with SG and 436). Naproxen is a nonsteroidal anti-inflammatory drug (NSAID) with potent analgesic, anti-inflammatory, and antipyretic properties. It is not a controlled substance.
The yellow, oblong tablet debossed with SG and a score line on one side and 436 on the reverse is an oral prescription nonsteroidal anti-inflammatory drug (NSAID) containing Naproxen (500 mg).
(Note: Another pill bearing this numerical imprint is a white, round tablet with 436 inside a raised hexagon, which contains Allopurinol 300 mg. Below is the detailed clinical profile for the Naproxen 500 mg (SG 436) formulation).