Yes, VIRILIZING is a Scrabble word!

Letter values in Scrabble US: V 4, I 1, R 1, I 1, L 1, I 1, Z 10, I 1, N 1, G 2.

Is it a valid word?

VIRILIZING is a valid word in the official Scrabble dictionary (US) and the UK Scrabble Dictionary, but not in Words with Friends (ENABLE).

produce virilism in or cause to assume masculine characteristics, as through a hormonal imbalance or hormone therapy

Not playable in Scrabble US: VIRILISE.