The Deputy First Minister said she has assured the other airports, particularly Glasgow, that ministers would remain neutral over which gets support.
She told MSPs on the Scottish Parliament Infrastructure Committee that the Government wanted to return the Ayrshire airport to profit then sell it back to a private operator, recouping the tax-payers' investment.
However, she said that will take years.
She said: "We aim to ensure it has no impact on 'team Scotland' airports. We will operate in a neutral way in terms of route development. It is important to give that assurance to other airports, particularly Glasgow, being the closest."
She said when support is given there will be "no special treatment given to Prestwick."
The Government has already invested £3 million at Prestwick and will put in a further £2m for the next financial year, with a package of improvements already authorised, and a report due from a special advisor next month for the airport's future business strategy.
Ms Sturgeon added: "A return on the investment is a longer term period and I'm not putting a guillotine on this. I can't say in three, four or five year it will be profitable."
She said there were opportunities at the airport, with land under used and more scope for income to be generated from retail and food and drink outlets than at present. Ms Sturgeon also said there were no plans to change the name of the airport to Robert Burns International, despite understanding the motives of local campaigners.
She said: "The Pure Dead Brilliant signage has gone. I was happy to see that when I visited.
"I have heard different opinions on it, but we have to market the airport outside Scotland and Glasgow Prestwick puts it in a geographical location where people know where they are flying to.
"The focus has to be on what has the best chance of returning the airport to profit. If there is evidence that calling it Robert Burns International will help do that or will make it harder we will look at it. We have not ruled it out."
Ms Sturgeon offered to return to the committee when more details were available.