Disclosed is a method of reducing and/or regulating the level of hydrogen in a polymerization reactor comprising contacting a first feed comprising a first amount of hydrogen with a hydrogenation catalyst prior to entering a polymerization reactor to form a second feed; then contacting the second feed having a second amount of hydrogen with monomers and a polymerization catalyst in a polymerization reactor to form a polymer. The first and second feeds may reside in a feed line from one reactor to another, a monomer feed line to the reactor, or in a recycle line to and from the same reactor.