Is oxycodone all right to take if your 14 years old?

Oxycodone is available as single-ingredient medication in immediate release and controlled release. Parenteral formulations of 10 mg/mL and 50mg/mL are available in the U.K. for IV/IM administration (Extract taken from Wikipedia).

It is a pain relief that works within 10-15 minutes on an empty stomach and longer on a full stomach.

You should always consult a Doctor before giving or taking any prescription medication, especially for children. Never estimate any medication.