Private student loans can be tricky to deal with.  If you have them, and you are looking for a better interest rate, it is possible that you could refinance, but the terms you get will depend on your credit.  Since the credit crises, fewer private consolidation loans are available.

Mark Kantrowitz of finaid.org has a web page about private consolidation loans here: http://www.finaid.org/loans/privateconsolidation.phtml

He lists some banks and lenders that might be offering these “products”. 

Be careful about assessing your options and for goodness sake, don’t consolidate federal student loans into a private student loan unless you are absolutely sure you know what you are doing.  Federal loans have important flexible repayment options and borrower benefits that would be forever lost.

Is there a way to consolidate private student loans without a cosigner if you don’t have much credit and a low income?

The obvious benefits to consolidating a student loan are that there will be a single payment, probably a lower payment, and one fixed interest rate. The fixed interest rate is especially attractive because this helps a person set up a budget easier. Of course the drawback to a fixed interest rate in this type of loan is that you may not be able to take advantage of future drops in interest rates if they occur.

Another drawback to student loan debt consolidation is the length of the term. It could be that you end up paying this loan longer than you would have otherwise and in the end pay more total interest. So be careful to get all of the data about your student loan debt consolidation loan before you sign the agreement..