Most forms of credit can have a positive influence on your Credit Score when managed correctly.
Loans can be seen as a positive way to build your Credit Score as it is often more difficult to build up debt on a Loan than on a Credit Card. Provided that you are able to make your monthly repayments as set up when agreeing upon the loan, this should help to build up your Credit Score.
If you are ineligible for most loans, you may find you are more likely to be accepted for Guarantor or Secured loans as these have a much lower associated risk. Lenders are more likely to accept customers for these loans, with a poor history, as if you are unable to make a repayment they have a contingency in place. However, you will need to ensure that payments are maintained as failure to pay could put your home at risk for a secured loan and mean your guarantor is pursued for payment for a guarantor loan.