Pros
Fast growing company, no worries about layoffs. Opportunities to be innovative, conceptualize and deliver a better way of doing things. Depending on your department, managers are generous with flex time. "To help people get the medicine they need to feel better and live well" is the company purpose statement, it's empowering to be a part of an organization working to help others. Lots of fun little perks, quality benefits, dedicated charity partners with the ability to participate and volunteer. Very smart and inspiring coworkers. I spend most of my days surrounded by very intelligent people.
Cons
High growth equals high turnover. If change freaks you out this is not the company for you. The project you are working on, manager you are working for will change, enough to make you a little batty. Work loads are always very high, there is more to do than you can manage so you have to be able to project manage efficiently and set boundaries for yourself.