I don't know the name of the movie and I haven't seen it completely. I just watched it for the last 15-20 minutes and so, I can't tell all the details.
The movie was in black and white. I saw the movie from the scene where the mad scientist sent a humanoid, gorilla like bipedal monster (its hide was hairy or grassy) to capture the female lead. The lady just had a shower and was wrapped in a towel when the monster captured her.
The protagonist went to the scientist's hideout and after a long fight (he destroyed the lab and killed or defeated the monster) he rescued the heroine still lying on the OT, unconscious and wrapped in the same towel.
The hero took the girl to his car where she gained her senses and kissed and embraced her rescuer. The closing scene shows the hero is still in her embrace, unbeknown to the fact that the girl's shoulder is turning hairy, suggesting that the scientist was indeed successful in his vile plan.
I saw the movie some 6-9 years ago on the Zee MGM channel. The time was probably 10-11 AM IST (Indian Standard Time). It was in English and had subtitles. It was an older movie probably during the 1950-1960s.
The movie didn't have any "alien" element (extra terrestrial) entity in it. The female lead was a blonde and the protagonist was wearing a suit.