The short answer is no, using Credit Karma does not lower your credit scores.
Credit Karma requests your credit report information on your behalf. This is known as a soft inquiry, and it won’t impact your scores.
Hard inquiries, on the other hand, can influence your credit scores. They’re typically placed on your reports when you apply for a new line of credit. So if you apply for a credit card or loan through Credit Karma or elsewhere, you will receive a hard inquiry.