How can I get a loan for breast augmentation?

Your surgeon can help. After discussing surgery with your plastic surgeon, they should be able to help. Most plastic surgeons work with at least one cosmetic loan company. The most well known is probably CARE CREDIT, but there are many others that can offer good rates.
Credit for BA. There are credit companies that loan mopney for cosmetic surgery. I use Credit Care. You can also us money from a home equity loan. Probably the most expensive way would be to use a credit card.
Many options. Typically it is best to see a plastic surgeon first and make that your first priority. In many instances, they may have resources that they can suggest. Commonly this will be listed in their website under financing options. There are a few innovative but suspect sources of funding including myfreeimplants.com.