Can I use the business expenses of my side business to reduce the income tax incurred from my full-time employment?

This assumes that the company I'm working for allows me to run my own business. If my side business is running at a net loss, can I use the remaining side business expenses less the income to offset my full-time employment's income?

My current gross annual income is about 500k and paying 7k a month as income tax. I'd like to start a business in order to pursue my passion while reducing the income tax instead of earning a fortune.